I am interfacing an SD card to the Z80, one of which uses 5 V logic (Z80) and the other uses 3.3 V logic (SD).  I believe the 3.3 V to 5 V level shifting will be taken care of by the 74HC595 I am using for serial input to parallel conversion (it considers 3.3 V to be logic level high and will output 5 V logic to the Z80).  However, the 74HC165 I am using to output serial data (MOSI) from the Z80 to the SD card will output 5 V logic which might fry the SD card.  I don't have any level shifting ICs laying around and would like to avoid having to wait for one to arrive in the mail.  I have read that I can use a crude voltage dividing circuit on the MOSI line, but I read that it tends to cause issues at higher clock frequencies.  Would the following circuit using two NPN transistors work (switching the input voltage to 5 V and the output voltage to 3.3 V)?    Or would it be better to replace the leftmost transistor with an inverter that feeds into the base of the rightmost transistor, keeping the emitter grounded, and having the collector pulled up to 3.3 V?  The 5 V MOSI signal from the 74HC165 would feed into the input of the inverter, and the 3.3 V MOSI pin of the SD card would be connected to the collector of the transistor.  So if I'm not mistaken, if the output is a logic level low, the inverter will power the base of the transistor, causing the output to the SD card to be logic level low as well.  If the output is a 5 V logic level high, the inverter will not power the base of the transistor, causing the output to the SD card to be a 3.3 V logic level high.  Or would this still be crude?  As long as there would be accurate data transmission at the correct voltage, I'm not concerned.  But please let me know what you think.  If this will lead to inaccurate or inconsistent data transmission, I would rather just wait for the correct IC.


Best practice between using LEFT JOIN or NOT EXISTS

Is there a best practice between using a LEFT JOIN or a NOT EXISTS format?  What is benefit to using one over the other?  If none, which should be preferred?  SELECT * FROM tableA A LEFT JOIN tableB B      ON A.idx = B.idx WHERE B.idx IS NULL     SELECT * FROM tableA A WHERE NOT EXISTS (SELECT idx FROM tableB B WHERE B.idx = A.idx)   I am using queries within Access against a SQL Server database.


Are Destiny characters backwards and/or cross-compatible?

From what I heard and remember hearing correctly, characters that are leveled up through the PS3 can be transferred to the PS4 version (assuming that both consoles have the game).  So what if I wanted to go back to the PS3 version with some friends? I only have the PS4 version at the moment--would my PS4 characters transfer over to the PS3 side? What if I wanted to go to the 360 version too to play with some other people too?


How can I create a 64-bit virtual network with VirtualBox?

I can't find an option to install a 64-bit OS on VirtualBox. I have a 64-bit host, but I can't find an option to make a 64-bit guest, only 32-bit.  Help please?


Is there a term that defines nostalgia for something you've never experienced?

Often I find I have a sense of nostalgia for things I've never actually experienced, in a way that rivals the same sort of feelings I have for things I have experienced.   For example when listening to music that was big before one's own generation or seeing old black and white photos of how people lived their lives generations before you were born.   It's an odd feeling I've heard many people talk about, but I've never quite had a word for explaining it.   Is there a term that describes this? Or is it still nostalgia?


gls option breaking hyperref howto combine options with hyperref

\glsadd{arts:BouguereauLeGuepier}   works just fine, but if I try to mark the main entry I lose the hyperlink in the PDF. Guess I am just using the format option wrong but after about half an hour searching manual and Google I am now just asking...  \glsadd[format={textbf}]{arts:BouguereauLeGuepier}   how do I use the format option correctly without breaking hyperref linking it to the page from the glossary?


How long does a spell last in the Harry Potter universe?

I didn't find this question or a related answer to my question.  Some spells like "Avada Kedavra" are spells that are intended to do one thing, the conjurer focuses on that spell and when they stop focusing, or the blast doesn't hit it's target, or the wizard dies, the spell ends.  A spell that opens a locked door for is another example, it either fails immediately or the door unlocks, either way the spell is over.  However, what about spells like the charming spells Harry, Hermione, and Ron used to conceal themselves?   They would get to a camp site, one of them would walk around the perimeter of the camp site and cast spells to conceal their location. Does the spell last in perpetuity? Does it only last while the conjurer is focusing on it? Does it last until it is dispelled by a counter spell? Does it just run out eventually?   I don'think the conjurer has to focus on it. It always appeared in the books and the movie that once these spells are cast the conjurer doesn't think about it again.  The charm spells are just an example. A love spell would fall into the same category as well. I believe the love spell Voldemorts mom put on his dad lasted until her mom released it and she didn't have to focus on it. There are many other examples of these types of spells as well.  You might want to consider Lily Potter's spell on the fish she gave to the professor as a gift in your answer. I believe it lasted until she died.  I don't know if each spell has a distinct amount of time that it lasts or if spells of this category follow a general rule.  Author's notes, interviews, etc. are welcome.


What is the easiest way to get reputations? As you guys can see I have one reputation in Stack Exchange and also for Stack Overflow, and I want to learn how to get a lot of reputation.


The below exception flown     LINQ to Entities does not recognize the method 'Boolean   Contains(Int32)' method,      and this method cannot be translated   into a store expression.   while trying to execute the below query  List<int> studentIDs = Common.getFilterStudents(); var query = from a in studentTable             where studentIDs.Contains(a.StudentID)             select a;   How can I filter the query using the studentIDs list?


I know that this is valid because by thinking about it, you can see it's true, but I'm just not sure how I would go about actually proving it mathematically. I've kind of tried proof by contradiction, since that's what I use most of the time, but it doesn't seem to work.    In my mind, A ∪ B ⊆ C kind of just implies that A ⊆ C and B ⊆ C.


As I ask this know; I purely ask this from a social point of view. As in conversations with others. It's a random thought and kinda funny when I started thinking about it.  What's a fact? Something believed and proven right. What's the Truth? Something believed to be what is right.  Why is it a fact can be the truth but the truth isn't always the fact? Opinions  But on the same notion...the facts can be changed with the Truth?  The fact of the matter is...I believe it is the truth.  What are the facts and what is the truth?


Find whether $\sum_{n=2}^\infty\frac{1}{n\ln^2(n)}$ converges

I tried to compare it with $1/n$ which I know diverges:  $$\frac{1}{n\ln^2(n)} \le \frac{1}{n} \Leftrightarrow \\ n\ln^2(n) \ge n \Leftrightarrow \\ \ln^2(n) \ge1\Leftrightarrow \\ \ln(n) \ge 1 \Leftrightarrow \\ n \ge e$$  If $1/n$ diverges and it is greater than the given series for all $n \ge e$... it should diverge, right? Yet the solutions say it converges. Is it because $2 < e$ and $a_2$ is part of the series? Does that make it converge or does that just mean $1/n$ isn't good for comparing?  Note: I could solve this by comparing with $1/\sqrt{n}$ instead but I am still wondering why this failed.


All is in the question, we can duplicate object with SHIFT+D but also with ALT+D, which is quite handy, because as you know every changes done on a linked duplicate object will be repeated on others linked objects ("same objects").  I've used it as example to create all the UVs of a box, all at once.. But now I would like to break it, to stop it... And I don't know how to do that...


Evaluate the line integral  $$ \int_C (\ln y) e^{-x} \,dx - \dfrac{e^{-x}}{y}\,dy + z\,dz $$  where C is the curve parametrized by $r(t)=(t-1)i+e^{t^4}j+(t^2+1)k$ for $0\leq t\leq 1$


This question can have many answers. For one, I would be enlightened to understand whether two photons can truly create an electron-positron pair, as well I would like to know if a photon is able to change other photon's directional path.  I've read on wikipedia about  and that it is possible to convert two bosons into two fermions, yet I haven't found a single experiment that says this has been done. I as well cannot find anything online that says whether a photon can influence another photon's path.  Finally, I want to just say that my brother has put this idea in my head that photons simply pass through one another without any effect whatsoever, so if you can ingrain a more true to reality understanding of photons affecting one another, that would be phenomenal.


Mid-century novel read in elementary school, about a woman with coloured skin and her guardian on a distant planet

Any help with this would be much appreciated, as it's been slowly driving me insane.  In elementary school (c. mid 90s), the entire class read a sci-fi novel about a girl with coloured-skin (green or blue maybe ?) essentially deserted on a (dusty/not an abundance of life ?) planet (in a different system) with her guardian (I don't think it was the same species, may have been AI), and she performs scientific observations and research, and something major obviously happens in the book (I think at one point she is separated from her guardian) for the sake of plot development.  I feel like I may have not finished reading it, so my apologies for not being more help.


What's going on here with the quoted quarter reputation?

This user is shown to have a +6268 change in quarter reputation when the user doesn't have that much reputation in the first place. What's going on here?


I was just teaching someone a little about SSH & VNC. I said I'd show him some things with TeamViewer. Then he asked me "Soo.. is this a VNC client? And I wasn't sure.   What protocol does TeamViewer use? It's obviously similar to VNC & RDP and so on. However, I can't seem to find much information on it.


Altas with rules on different layer than the cover layer

I need to generate an atlas based on a polygon shapefile, but I'd like to see just what is inside the polygon itself. Maybe with rules that involves other shape's attributes. Any suggestion?


I want to use python to move the UVs of the selected objects. I am having trouble with moving the UVs. When I run my script I moves the objects instead, not the UVs. All object have exactly 1 UV map.   My approach the problem:  for mesh in selection:   for UVs in mesh   select all UVs   move UVs     Here is my code.  import bpy  scene = bpy.context.scene for count, ob in enumerate(bpy.context.selected_objects):     if ob.type == 'MESH':         scene.objects.active = ob         bpy.ops.object.mode_set(mode='EDIT', toggle=False)          bpy.ops.mesh.reveal()         bpy.ops.mesh.select_all(action='SELECT')          # execute any editmode tool         move_x = count % 10         move_y = count // 10         bpy.ops.transform.translate(value=(move_x, move_y, 0), constraint_axis=(True, False, False), constraint_orientation='GLOBAL', mirror=False, proportional='DISABLED', proportional_edit_falloff='SMOOTH', proportional_size=0.263331)           bpy.ops.object.mode_set(mode='OBJECT', toggle=False)


I am searching for an appropriate possibility to render my scenes. Therefore I am searching for an adequate render farm which supports Blender + Octane. I am working with OctaneRender® Prime (Free Tier | CUDA). Does anyone have experience with this? Greetings Max


Word or phrase for "one needing to see it to believe it"

What's a word or phrase that could be used to describe a person who needs to see the evidence for a claim in-person before believing it?


Restore Python to default on ubuntu 12.04

I am totally aware a question of similar nature is asked before. But the answer there is not doing any good for me.  I have installed python 2.7.6 in addition to system default 2.7.3. And now my system is screwed up completely. Now I want to remove the 2.7.6 and get back to my system default. update-alternatives command on python is not working!  I have installed the 2.7.6 by downloading source and triggering "config, make, sudo make install" commands.  Please help.


Prove that $(1+\frac{1}{m})^m > (1+\frac{1}{n})^n$ when $m>n>0$ are real numbers, using elementary way.

Please tell me how to solve this one. Given that $m, n$ are positive real numbers and $m>n>0$. Prove that $(1+\frac1m)^m > (1+\frac1n)^n$.   Now I am willing to prove this through elementary inequality techniques( like AM-GM inequality etc). I know that the same can be proved using calculus and the fact $\{(1+\frac1x)^x: x >0\}$ is an increasing function.   But without using the calculus stuff, can we prove it in simple inequality way ?  Thanks in advance


Does control and target matter in the CZ (Controlled-Z) Gate?

IBM Quantum Experience and other Algorithm Creators generally draw the CZ gates like this:  Does it not matter which qubit is the control and which is the target? If so why?


To do the equivalent of Python list comprehensions, I'm doing the following:  some_array.select{|x| x % 2 == 0 }.collect{|x| x * 3}   Is there a better way to do this...perhaps with one method call?


I have made many figures with tikz and want to include them in a template. Unfortunately I used ex as a measure and the template I have to use redefines the font size. THis leads to wrong distances in the figures. is there a way to set the font size for all tikz figures in a document, so I do not have to adjust my figures?


How to check object values is null or not?

I'm creating one Object and assign null value then push some values into created object now i want check object is null or not?  here is my code  var data = {};     if(typeof first_name != 'undefined'){         data['first_name'] = first_name;     }      if(typeof last_name != 'undefined'){         data['last_name'] = last_name;     }  //checking value is null or not  if(typeof data !== null){     console.log(data);     }     else{     console.log('No Any values');        }   its give O/P this: Object {}


I have this limit: $$\lim_{n\rightarrow\infty}\sin\left(\pi\sqrt[3]{n^{3}+1}\right)$$ I don't even know if it exists. If so, what its value ? Really don't have any idea..


I'm not going crazy or anything but after I hibernate my PC it just decides to turn back on again without me doing anything. I have checked my BIOS and it shows nothing that will turn it back on.  Any suggestions on what I should check?


I have two questions about using regular expressions inside a shell.  1. Use of *  According to :     *: The asterisk indicates there is zero or more of the preceding element. For example, ab*c matches "ac", "abc", "abbc", "abbbc", and   so on.   However, when I write rm test*.iso, it will delete all files beginning by "test" and finishing by ".iso" whatever there is (or not) between "test" and ".iso". So, the file "tes.iso" will be not deleted.   If you take the abc example, according to wikipedia, "ab*c" matches "ac". Therefore rm ab*c should delete an "ac" file. Why rm does not use regular expression as wikipedia describes them?  2. Use of - and ?  Still according to :     ?: The question mark indicates there is zero or one of the preceding   element. For example, colou?r matches both "color" and "colour".      +: The plus sign indicates there is one or more of the preceding element. For example, ab+c matches "abc", "abbc", "abbbc", and so on,   but not "ac".   "?" seems to work like "*", that is to say "?" symbol replaces one or zero element (but not the preceding one contrary as what wikipedia says).  I don't know how to use "+" and this is my second question. I'm also interested by any tricks concerning regular expressions and rm, cp, ....


Does option "-h" for "ls" display size in MB or MiB and is it consistent over Unix-based systems?

The usual ls command can display the size of files with the option -h and I am having a little doubt about it being display in  or .  For example :  $ ls -lha drwxr-xr-x 2 user group 4.0K Apr  2 21:49 .  drwxr-xr-x 5 user group 4.0K Apr  2 21:49 .. -rw-r--r-- 1 user group 129M Apr  2 21:49 2018-04-02T21:49:08.981976.hdf5   So, this leaves me with 2 questions :   Does ls -lha displayed the size in MB or MiB? Is it consistent across Unix-based operating systems and their own versions over time?   N.B.: Not only commercial Unix-based operating systems should be considered for this question.


How to permanently block udp on all ports on all connections including pppoe

I'm getting swamped with outbound udp requests and it's blocking my internet connection.  While I figure out what's going on I'd like to block all outbound and inbound udp. I'm connecting via pppoe dial up but want to block on all ports and all connections. Is there a way to do this that won't interrupt my pppoe connection?  I've tried updating iptables but this seems to only block one port at a time if I understand correctly.  Though I have rules in my firewall to block the ports it seems to be too late.   For newbies like me it is difficult to get the pieces together and I couldn't find the answer on searching because didn't know to search for iptables and that doesn't cover the udp component. I have my question answered by think this should remain open for others as I believe it might be helpful.


How to post a link to an android market app?

You can post a link to an android market application by useing a link that looks like:     market://search?q=pname:package    While browsing the market, is it possible to find an app's package name? Or is there a convenient way to get or share a link to a market app? Is there any way to post a link to a market app that normal (non-android) browsers can make use of?


Confidence Interval for predicted value in a simple regression model

hope all is well. I am taking an econometrics class now and I have stumbled upon a problem that I hope that you can help me with. I want to calculate a 95 % confidence interval for a predicted value in a simple regression model. I have found the Residual Sum of Squares for the model, and it is $20.5465$. $\hat Y$ is $1.7354$ when $X$ is $19$. Do you have an idea of how I can go on a about to calculate the confidence interval. I understand that you guys are used to more complicated problems, but I thought I would ask as I am eager to understand.


For positive, real $a$, $b$, $c$ with $a+b+c=1$, show $\sum_{cyc}\frac{a^3}{a^2+b^2}\geq \frac12$

I have some problem solving the following inequality:  Let's assume that $a$, $b$ and $c$ are all real, positive numbers, and $a+b+c=1$. Prove the following: $$ \frac{a^3}{a^2+b^2}+\frac{b^3}{b^2+c^2}+\frac{c^3}{c^2+a^2}\geq\frac{1}{2} $$  The only thing I could prove (using the Radon inequality) is that the left hand side is greater or equal with $\frac{1}{4}$. Any ideas? I almost tried everything.


How to uninstall software that was installed by "make install"

If I install a software by executing:  ./configure make make install    Is there a generic way to uninstall it (like sudo apg-get remove)?


I trying to get info in database and sending for an object called Question.  When i got null in database and send it to the field of the object.. I suppose that field will be "null", cause the field is an String.  But i tried all ways to verify it and i cant...  I tried:      Question a = new Question();     a.setAnswer(database.getAnswer(id));     // Way 1     if(a.getAnswer() == null) {             Log.d("Way 1", "successfully");     }      // Way 2     if(a.getAnswer() == "null") {             Log.d("Way 2", "successfully");     }     //Way 3     if(a.getAnswer().equals(null)) {             Log.d("Way 3", "successfully");     }     // Way 4     if(a.getAnswer().equals("")) {              Log.d("Way 4", "successfully");     }   But I didn't got result...  I put in log to log my Question.getAnswer() too:  And here's the result:      D/Here == >: null


General Attitude: Stack Overflow: Non-constructive attitude, rather than constructive criticism

Is it just me, or is there a general non-constructive attitude, rather than constructive criticism on Stack Overflow?   I am having difficulty aligning my internal compass. I understand that certain questions need to be thrown out, and I understand that certain questions are fitting for certain Stack Exchange sites. I understand that the sites ore community moderated, and that a general "average" of community members' persona's will be reflected.   My issue is with the fact that, in my opinion, some users are a bit trigger happy with the down vote button, or are just downright rude, without providing any feedback to the user in question.   This is in my opinion much more non-constructive to the site than a Q that is slightly off topic, or not worded correctly. When did the down vote become a feel good weapon? I see this regularly where questions not deserving of down votes (in my opinion), get down voted by a what seems like a factor, because a trigger happy user down voted the Q, rather than tried to fix it. And now a bunch of users exercise their down vote button, because someone else did, and they can also do it.  I know we cant possibly moderate each down vote before it is applied, and I understand an "average" will be the outcome, but it seems like the good guys, interested in actually contributing in a constructive manner, are outweighed by the, in my opinion, non constructive guys. Its almost like the perceived anonymity of down voting, is being exploited.   I attempted to flag one such post, and the moderator replied with (We can't say why people vote the way they do). I understand that the community moderation is the power of these sites. But is it being abused?  Situations are created where legitimate questions, that may have been genuinely helpful to other users, are being "played" with by people exercising their privileges instead of their contribution.  (Again, the above all in my personal opinion)  From personal experience, I can attest to the fact that this behavior is demoralizing, to say the least.   I am personally trying hard to contribute. Not for rep, but to give something back as SO has really been helpful to me on multiple occasions.  An example, but not specifically aimed at for the above, is provided in the link below this post.  The original question, although broad, could be answered or "nudged in the right direction" in my personal opinion.   The original question was aggressively acted upon, which I understand needs to happen in some cases. In this case, I feel the original poster, instead of being chased away with a broom, could have been pointed or helped, even if not on SO.  I indicated in a comment that this might have to be moved to a different site, like programming, if its not fitting for SO. I attempted to use the community wiki option, and created a new Q&A, which I thought would go to the wiki, and not as a new question. I again, indicated that SO might not be the right place, and that I was making an "attempt" to contribute.  Instead of constructive behavior, I experienced more non constructive criticism, than what I would care for when trying to contribute.  As I said, maybe its just me. I guess my question revolves around determining if its just me seeing things.   (10k only)


Prove that for the series $\sum_{n \in \mathbb{N}}|\zeta_n\mu_n|$ to be convergent for all $\zeta \in l^p \implies \mu \in l^q$

Prove that for the series $$\sum_{n \in \mathbb{N}}|\zeta_n\mu_n|$$ to be convergent for all $$\zeta \in l^p \implies \mu \in l^q$$  I used Holder's inequality to prove that $$\sum_{n \in \mathbb{N}}|\zeta_n\mu_n| \leq \|\zeta\|_p \|\mu\|_q $$  But I cannot find a $\zeta= (\zeta_1, \zeta_2,....)$ such that $A(\zeta)=\sum_{n \in \mathbb{N}}|\zeta_n\mu_n|=(\sum_{n \in \mathbb{N}} |\mu_n|^q)^{\frac{1}{q}}$. $ \zeta=??$


Why Ubuntu 18.04 has LibreOffice 6.0.7? How can I upgrade that to version 6.28?

I recently saw a social media post from Libre Office about them phasing out Libre office 6.28 and moving to Libre office 6.3. But when I checked my fully updated 18.04, I see that I am having Libre office 6.0.7. Why my version of Libre Office is so old ? What can I do to get it updated to 6.28 and then automatically to 6.3 when Libre Office pushes it?


Proof that $n!\leq {(\frac{n+1}{2})}^{n}$

I don't know what to do with this. Nothing works. I hope somebody can help me to find a decision $$n!\leq {\left(\frac{n+1}{2}\right)}^{n}$$


Having problems with ACL in Trusty desktop version, I want to know if the acl mount option is really mandatory for an ext4 partition?   Since with or without this option, setfacl never complains support is missing, I wonder if setting the option when it is not mandatory anymore would cause issues?


Is it possible to answer a question that has been closed and put "onhold"?

I came across this , which is kind of asking about books, and has been close voted and put onhold.  I was the last person that voted to close (at that time there was no answer).    First, I thought it was a few seconds lag, but the difference is 1+ minutes.  Not sure whether this is a bug or problem with timezone?


When do we use "any" with countable nouns?

I was reading these questions and I noticed that in one of them, "any" is used with a singular countable noun. And in the other one "any" is used with a plural countable noun. I wanted to know why that is ?


Where should code optimization questions be asked?

Is there any site on SE where someone can ask a question on how to optimize a piece of code they have?  If yes, which?  itself? Or maybe ?


google-chrome-stable keeps asking if it should be set to default

Since the Ubuntu 15.10 upgrade, google-chrome-stable keeps asking if it should be set as default browser, even though it already is. I tried to reinstall it, but that didn't help. Any ideas?


Hi I want to draw a performance profile directly from python, and the results of implementation are stored in lists, what can I do next? New to python, hope someone can help, thanks in advance.


How to write today's date which does not change afterwards?

In latex, the command \today displays today's date.  Consider that I write something like: Updated news: \today. It appears like     Updated news: Saturday, October 24, 2015   After a while, when I recompile the document, say 4 days later, it will say     Updated news: Thursday, October 29, 2015   at the very same line. Is there a way to make a \today static? In other words, I'd like my document like a blog. When I insert a date, I want that date to stay.  How can I do this?


Polynomial with $f(x) =17$, show that it has at most $3$ integer roots

Problem:    Suppose $f(x)$ is a polynomial with integer coefficients. If $f(a)=17$ for some integer $a$, show that $f(x)$ has at most $3$ integer roots.  I tried to solve this problem but ended up getting the result as a maximum of $4$ integer roots. Here's the method I used:  Assuming that the three integer roots are $\alpha$,$\beta$,$\gamma$ $f(\alpha) = f(\beta) = f(\gamma) = 0$  As $f(m) - f(n) = k  * (m-n)$, where $m,n,k$ are integers  $f(17) - f(\alpha) = k  * (17-\alpha)   17 - 0 = k * (17-\alpha)$  $(17-\alpha)$ can now be $-17 , -1 , 1 \text{ or } 17$ Thus $\alpha$ can be $34 , 18 , 16 \text{ or } 0$  Similarly $\beta$ and $\gamma$ can take any of the remaining values, leaving one last value for a fourth root.  Could anyone suggest any other methods or point out where exactly I went wrong?


I have a simple question about static variables. If I declared a static variable in a function:  void main() {     int k = 0     while(k<=4)     {         fun();         k++;     } } int fun() {     static int i=5;     i++;     printf(Value %d\t", i);     return 0; }   As I know, the function will deallocate after returning. But where is the i value stored. Is a static variable like a global variable.


Does the curvature of spacetime theory assume gravity?

Whenever I read about the curvature of spacetime as an explanation for gravity, I see pictures of a sheet (spacetime) with various masses indenting the sheet to form "gravity wells." Objects which are gravitationally attracted are said to roll down the curved sheet of spacetime into the gravity well. This is troubling to me, because, in order for objects on the locally slanted spacetime sheet to accelerate, gravity must be assumed. Therefore I ask; does the explanation of gravity as the curvature of spacetime assume gravity? If yes, what is the point of the theory? If No, what am I missing?


Please implement hats in the mobile StackExchange App

I am aware of  . This is a feature request to the developers to add hats to the app.  I know everyone would love the ability to see those amazing pieces of apparel, and I'm wondering if they are coming to iOS and Android apps. Why should / shouldn't hats be implemented on the mobile app?    As you can see, it's a very boring profile picture I have without a hat.  I am not asking "Why aren't hats supported?" but instead I am asking this as a feature-request, one that I hope will make it to the mobile app, and one that I believe that most users would enjoy.


Is there an Edge Crease tool for the Smooth option (similar to that used for the Sub surf modifier)

I know this is a long shot (and I'm going to have to go back and delete/recreate my arrays with a subsurf mod) but since I've already locked in most of them:  I was wondering if there is a tool that acts as an Edge Crease (for the smooth option) that'll allow me to sharpen up some of the edges on a tire.  Currently my rendered tire looks like this:    When smoothing things definitely get a little TOO smooth.    In the end, I'm ok if there's not, just hoping to save some time :)


AbiWord is launching on every reboot on ubuntu 15.04 gnome

As the title says, AbiWord is launching every time after logging into my desktop without any user interaction. I've tried to find an entry in init.d but couldn't find something. This happens since the first day I installed ubuntu.   I found this , the only "answer" is      My solution is simple uninstall Abiword. Libre is fine for my   purposes.   Does anybody know why this happens or where I could disable it?


Disable vertical tabs by content type or user role

Some users may only have the ability to edit one of the fieldsets that shows up in vertical tabs on the node edit form. In such a case it looks rather silly to be using vertical tabs since there is only one vertical tab to choose from. See screenshot:    So, is it possible to disable vertical tabs by user role? Or, barring that, disable them altogether for certain content types? For my use case I just want Location to not be displayed in vertical tabs.   I tried Renderable Fields and Field Group together but they managed the form incorrectly (buggy, I think). Arrange Fields can't separate out Vertical Tabs.


Why each sphere admits an orientation reversing diffeomorphism onto itself? (For even dimensional ones can we take conjugation map?) And why complex projective spaces do not admit? Is there a geometric way to see this without using characteristic classes?


Linear Regression - with or without intercept

Difference between linear regression with or without intercept? Why and when to use which one?


Complete Sign Up problem on Stack Overflow Portuguese

I have same problem of this , but I can't comment that because don't have reputation.


About the geodesics in general relativity

I'm learning general relativity from the book " ". The field equations are derived by the Hilbert - Einstein action and are written in the form  $$ R_{\mu\nu}-\frac{1}{2}R\,g_{\mu\nu}+\Lambda\,g_{\mu\nu}=kT_{\mu\nu}$$ where $k$ is acostant that should be determined. The authors find this $k=\frac{8\pi G}{c^4}$ by imposing the well known conditions of "Newtonian Limit". The first requirement is the following      The particles in free fall moving along geodesics induced by $g$.   This is a postulate? By the Einstein equivalence principle we know that locally we can eliminate the effects of gravity and so living in a (flat) Minkowskian space-time but there is not mention of the above statement. I agree on the fact that once we have a curved space-time, in presence of gravitational fields, it is natural to require that the free falling particles move along the geodesics, but this can be proved or it is postulated?


Is it possible to directly access files out of a symlink-directory?

Say I have this directory structure: foo  │ ╲ bar baz  │    ╲ wun ← wunl  │ blarg  Here, wunl is a symlink pointing to ../bar/wun. Now I can $ cd foo/baz/wunl/blarg  At this point, I'm not “actually” in wunl, which is after all not a directory but a symlink, yet pwd suggests just that: $ pwd /home/.../foo/baz/wunl/blarg  I can also cd out again with relative paths, as if baz/wunl had been a normal directory: $ cd ../../ $ pwd /home/.../foo/baz/  However I cannot use such relative paths to, say, copy a file: $ pwd /home/.../foo/baz/ $ touch test.txt $ cd wunl/blarg $ cp ../../test.txt . cp: cannot stat '/home/.../foo/bar/test.txt': No such file or directory  So cp tries to use the “realpath expansion” and tries to .. from there, instead of from the “pseudopath” that pwd and cd work with. I can still get the desired copy with this hack: $ ( cd ../../ ; cp test.txt wunl/blarg )  but this is fiddly and doesn't support tab-completion. Is there a better way?


Why can't a rope be pulled completely straight?

I have found several discussions on how to calculate the sag of rope that is tied off at two points (like a tightrope), and I understand it to a certain extent. What I can't wrap my head around is how come it is impossible to pull the rope tight enough that the sag goes away completely? I'm talking about big thick ropes, like a tightrope that has to be strong enough to hold at least one person. I can pull a piece of string so that it's perfectly straight...does this just have to do with scale?  I like physics, but I'm not great at it, so if someone could answer this in as close to layman's terms as possible, that would be greatly appreciated.


Insert Bash code with coloration into my latex report

I am writing a long report, and I need to include some code I wrote. I would like my code to appear colorized, as can be seen in some text editors, but not by using the verbatim package.  I need to colorize two distinct languages:   Bash language (Java language)<= Already have it, thanks!   Thank you in advance for your help.


Is there an updated pGRouting tutorial to this:    Trying to following it using QGIS 2.14.0 Essen +  PostgreSql 9.5 (pgAdmin III) but can't get it to produce the query output result route, in fact there is not result from running the query (0 rows)


I'm currently running 14.04lts but i want to upgrade to 15.04. The things is that in the file where you change the prompt=lts to normal, when I try to change it to normal i can't save it and i just want to know how.


Stack Exchange Presence at Local Conferences?

got me thinking about conferences.  Stack Overflow has  (for the most part),  with , has , etc.  All in all, great exposure and lots of community support.  But I feel like there's a gap between the big conferences and the meet-ups... The local conference scene.  At least in my area there are lots of , , , etc.  (The links are just for the stuff I know about off the top of my head and have attended in recent months.)  And I feel like the Stack Exchange community has enough of a presence in enough areas that we can perhaps bring something to those local events.  I'm sure it would have to be a lot more formal than the local meet-ups, since sponsorship funds are generally involved.  At the same time it should be much less formal than the big conferences, since Stack Exchange staff doesn't necessarily need to be involved.  The question just becomes, how do we connect the volunteer community organizers (such as the meet-up organizers, who've done a fantastic job) with Stack Exchange on a formal enough level that we as a community can effectively represent the community and the company at these local events?  I've specifically said Stack Exchange rather than Stack Overflow because the latter might not be the only applicable community.  It's certainly the largest, but communities like Server Fault could certainly stand well enough on their own at local conferences as well.  And the groups can mix very easily, being all under the Stack Exchange umbrella.  (For example, I imagine both Stack Overflow and Server Fault could be interested in a weekend event about setting up, administering, and developing against Windows Azure.)  What does the community think of this?  I'd love to hear from users who have organized events in the past and can share their expertise on the matter, as well as Stack Exchange personnel who can speak to the idea from the company's perspective.  Is something like this even viable?  It is something we can drive by features in the current site engine, new small features added to it, a new site altogether, or direct contact between staff and volunteers?  I'll volunteer to help where I can, as I'm pretty much addicted to the local conference scene (at least Microsoft's stuff for now, since that is my bread and butter at work) and there's always a time slot or two (or more) where I'd rather man a booth than stare at a projector screen.  Thoughts?


Where should I ask a question about processes?

I have a question on how to be compliant with all mail server's expectations, but it's not a technical question about how to configure the mail server itself. It's more about respecting best practices on that field.  Where should I ask for this?  If more details needed, I actually asked the question in the wrong place:


If gravity can bend light, why can't gravity slow light. At least momentarily? Wouldn't that give the illusion of the universe expansion speeding up?


Any way to tell apart a CPU defect from a mainboard defect?

I have a fairly modern desktop computer, an AMD Athlon II X2 based silent PC, that does not work.  When turned on, it will start physically (all fans are rotating, disks start up...) but not give a signal on any of the graphics ports (DVI, VGA, and HDMI, I tried all three). Also, the reset button does not seem to have any effect.  I have stripped the mainboard bare of all SATA connections, extension cards, and the one 2GB RAM chip to eliminate them as the problem source, but to no avail, so I think it's fair to assume it's either the mainboard or the processor that are at fault.  However, I have neither a replacement mainboard, nor a replacement processor handy to identify which one is broken. The cause of the defect is unknown, so for all I know, it could be both. Therefore, I'm reluctant to buy replacement hardware blindly before knowing more.   Is there any way to further diagnose (or at least get some indication) which component is broken without buying replacement hardware?


why is the foot skin still kinda sticking on the ground?

is this happening because of the rig or something else? and how can i fix


Solve the triple integral $\iiint_{K}\left(x^{2}-z^{2}\right) d x d y d z$

How does one go about solving the integral:   $\iiint_{K}\left(x^{2}-z^{2}\right) d x \,d y \,d z$  where K is the body that is given by   $x \geq 0,\: y \geq 0,\: z \geq 0$ and $x+y+z \leq 1$  I assume I am to convert this to spherical coordinates but I'm really unsure as to how to proceed.  Thanks in advanced


Just curious to get an idea of how it works, could I pause a project to shutdown my PC for the night and then continue the next day, as I'm aware it can take a long time to render some projects.  It's different from the question it's been link to for similarities, in the sense that it wouldn't be in the same session, the PC would  be turned of then back on, it's a difference worth considering.


Say I am playing clash of clans or boom beach. A crash in the middle of an attack could be very fatal.  What happen is I was playing and then suddenly the screen go back to the home screen. No other apps are running. I can click the multi task button (or whatever button in bottom right) and the original apps shows up. However, it seems to be a crash because if I select it it reloads.  Does android have event logs I can check. What's going on? I got 4 GB memory. It's asus zenphone 2


Why does the single slit in Young's Double slit experiment need to be narrow?

I've read in many places that it's to do with illuminating both double slits by diffraction, even though the interference pattern on the screen would be an overlap of different interference patterns.   However, would the light that emerges from this wide single slit still be coherent? That is, has a constant phase difference, assuming that it's light from a filament lamp that has just passed a filter.  I thought that it wouldn't be coherent, since light can pass through it coming in all different directions, whereas a narrow single slit confines the waves into an almost perfect narrow path to provide a constant phase difference. Is this right?


Does every complex (or real) vector space posses a vector topology in which it is separable?

Let $E$ - be a complex (or real) vector space. Is it always possible to find a Hausdorff locally convex topology $\mathcal{T}$ on $E$ such that $(E, \mathcal{T})$ is separable?  The motivation goes from this question . While answering on that I had to note that not all vector spaces possess a metric in which they are separable. Now I wonder if the same thing works without metrizability.  It seems to me that separability makes some constraint to the cardinality of $E$ or its algebraic basis (also called Hamel basis). I can prove that if $E$ possesses a metrizable topology such that $E$ is separable then $E$ is not larger than continuum. But for arbitrary topology there is an issue with the cardinality of local base of $E$. Also I can't imagine a general construction that gives a topology $\mathcal{T}$ if it is possible for all vector spaces.  Assume that such topology exists. If we consider a local base $U_\alpha$ where $\alpha \in I$ then there is an injective map from $E$ to $2^{S \times I}$ where $S$ is a dense set. This function maps $x \in E$ to a subset $\{(s,\alpha): x \in s + U_\alpha\} \subset S \times I\}$. It is injective since $S$ is dense and $E$ is Hausdorff. Then cardinality of $S \times I$ equals cardinality of $I$ since $S$ is supposed to be countable. Therefore $E$ is not greater then $2^I$. For simple case of metrizable spaces (for which I is countable) it gives that $E$ is not greater then continuum. But in general I don't know how to estimate cardinality of $I$.


Keep sourced file after script execution

Is it possible to keep source from an executed script  without sourcing it ?  Here is the script install.sh:  JJJ=bar   When i execute the script like ./install.sh, after execution, i got the following prompt JJJ :      user1@localhost% echo $JJJ          When i source the file, like source install.sh, i got the following value for $FOO :     user1@localhost% echo $JJJ   bar   For, now all is ok.  But i would like to know if there is a way to set the JJJ value and keep the value of JJJ after script execution, without sourcing the script. In other words, is a their a way that after ./install.sh, the following prompts gives :     user1@localhost% echo $JJJ   bar


How does having multiple permanents with the same name affect those permanents' abilities?

Many abilities in MTG use a permanent's name in the ability. Does this mean that if I have 2 copies of that permanent, the ability will affect both permanents?  Activated ability example:  - If I activate the ability of one of my Vector Asps, can I choose which of them gain infect until end of turn? Or will they both gain infect?  Triggered ability example:  - If I cast a second Sin Collector, when it enters the battlefield, will each Sin Collector trigger and allow me to exile a total of 2 cards instead of 1?


Eek! My Photos app says it's going to delete a huge bunch of my images in 28 days!

I have a MacBook Air and just updated to macOS Sierra, which automatically installed the "Photos" app to replace my old "iPhotos" app. As I scrolled through the "Photos" app sidebar I checked to see that all of my photos were there in the "Photos" folder (at the top of the sidebar). Then I scrolled down to the "Recently deleted" folder and to my horror saw a huge number of my images shown under the advisory that these photos would be permanently deleted in 28 days! They are  photos that I didn't delete from iPhotos or Photos, and I don't want them deleted. I looked again at the "Photos" folder and saw that those same photos — the ones destined for deletion in 28 days — were also showing up in the "Photos" folders. I don't need two copies of them but I am wondering if they are safe if I see them in the "Photos" folder?  Now I did keep copies of my images both in my old iPhotos app and in another photo app (called My Pictures), and I did recently delete a large number of them from my "My Pictures" file to get more disk space, but I didn't delete the duplicates of those same photos from my iPhoto files. Is it possible that the photos I now see as listed for deletion (under Recently Deleted) are those duplicate photos I deleted from my My Pictures folder?


Book, probably published before the 1980s, about a pair of teenage girls (twins?) raised by dolphins and slowly integrating into society

I picked up a copy of this in my grandmother's house, probably 10-20 years ago. I think my mother said it belonged to my aunt Mary, who probably would have read it around the 1970s (high school / college age). The primary characters were a pair of teenage girls who had an older male professor as their guardian. I'm pretty sure the girls had long blonde hair and blue eyes. I don't remember if the girls were feral children raised by dolphins or if they were part of an experiment by the professor, but they were amazing swimmers who could hold their breath for longer than any normal human. Other than that, I just have a few scenes dancing around it my head. First, the professor kept the girls on a boat, presumably so that they could be closer to water. Second, there was a scene where one of the girls put on makeup to try to be normal, and went off on a date. Her sister observes from a hiding place. The date in question sees the sister watching and assumes that this is a sign that they're both interested and he gets more aggressive. She interprets her date's kiss as an attack and goes off of the side of the boat, leading him to think that he killed her (my vague memory is that said date might have been an assistant to the professor or he might have just been a local townsperson).  The girls might have had a psychic connection with each other, but I'm less sure about that. Unfortunately, I read this over a decade ago, and I don't think I even got to finish the book. The front cover had one of the girls on the boat and I want to say that the title talking about them as "dolphin girls". It might have been part of a series.


Is dd able to overwrite parts of a file?

I have a 1TB big file (disk-image from a damaged drive) and a 1.3MB small file (beginning of a disk-file).  Using the contents of the small file, I want to overwrite portions of the big file. That is, I want to insert/overwrite the first 1.3MB of the 1TB-image using the small file.  Using small temporary files for testing I was unable to overwrite parts of the files. Rather, dd overwrote the files completely. This is not what I want.  Is dd able to do this?


Reading GeoJSON from external file in Leaflet

I found the following script on the web but I don't know how to change the way to read JSON code. In the script the JSON code is included in a var called sitec but I need to read that code from an external file. Any ideas how to do?  <!DOCTYPE html>       <title>JSON - Leaflet</title>     <link rel="stylesheet" href="https://unpkg.com/leaflet@1.5.1/dist/leaflet.css"           integrity="sha512-xwE/Az9zrjBIphAcBb3F6JVqxf46+CDLwfLMHloNu6KEQCAWi6HcDUbeOfBIptF7tcCzusKFjFw2yuvEpDL9wQ=="           crossorigin="" />


I can't seem to type or paste Japanese characters into a text object. Is there a way or is is this just a known deficiency or bug? ありがとう。 Thanks!


Vigilant is an adjective, so "The vigilant worker spotted a problem" is correct but what about "We must remain vigilant"?


Creating "Inner Buffer" using ArcGIS for Desktop?

I am currently searching for how to create an "Inner Buffer" in ArcGIS for Desktop?  I have a lot of polygons (houses) in one feature class, and one big polygon (in another feature class).   I want so select all houses contained in that one big polygon within a distance to the outer border (e.g. 1000 meters).  Select Layer By Location could be one possibility to solve this but I can't figure out how.


I want to unintall Ubuntu which I installed alongside windows 10

I recently installed Ubuntu 16 alongside windows 10. Now i want to uninstall Ubuntu and without touching windows 10


Who first actually enslaved house elves and why did they? There is basically nothing out there to help you.


Process a text file and a gunzipped text file in single command

I have a use-case to process following file types:  1 - mylog_1.log 2 - mylog_2.log.gz   I have to run two different text processing commands on each of them as follows:  cat mylog_1.log | grep text | sort | uniq -c zcat mylog_2.log.gz | grep text | sort | uniq -c   (cat, grep, awk and sed are the frequently used commands)  Is there a way to process both file types in a single command without unzipping the file?


constucting a matrix with lists of lists in Python

I try to construct a matrix with a lists of lists in Python3. When I implement the following function,  def myfunction(h, l):     resultmat = (h+1) * [(l+1) * [0]]     for i in range(1,h):                 for j in range(1, l+1):                resultmat[i][j] = i + j      return resultmat   I get the following result:   myfunction(2,3) Out[42]: [[0, 2, 3, 4], [0, 2, 3, 4], [0, 2, 3, 4]]   I had expected that the first rows and columns would be filled with zeroes, and that all other elements would be the sum of the row and column index. This is not exactly what I get here, where each row is a copy of the others. Can someone explain me (a) what is going on (b) how I can solve this problem?


I have nested gather and align according to  \begin{gather}        \sum\limits_{i=1}^n i + \text{expression} = \dfrac{n(n-1)}{2} \label{l1}\\        \begin{align}             a+\text{expression}&=b \\ %\label{l2} doesnt work             c&=d+\text{expression} \\             e+\text{long expression}&=f-\text{expression}        \end{align}  \end{gather}   to get an output looking like this:   The problem is that it is not possible to label all equations separately. The problem is identical to that discussed in , except  that in my problem the first line needs to be centered.  Thanks for any help.


If X1 X2 are independent Uniform variates on (0,1), Find the distribution of Z=X1/X2.   I tried using the CDF method where P(X1<=zX2) is equal to z/2 when z is in(0,1). However, I am unable to find the CDF when z is greater than 1


I had created the xml document with xml version="1.0".  In that document I need to use the greater than symbol > and less than symbol <.  How should I include those symbols? It's not working.  &gt; and &lt; are not working for me.  Is there any special encoder for this?


Using (Math.random() * ((upperbound - lowerbound) + 1) + lowerbound) in JAVA generates a number out of the specified range

I know how this works in principle:      (Math.random() * ((upperbound - lowerbound) + 1) + lowerbound);   But if I use this for negative numbers for example: I want to generate random numbers ranging from -30 to -35, I use the same formula:      (Math.random()*(-30-(-35)+1)+(-35));   But the generated numbers contain -29 too. Is there a way to avoid this ? I found the upper solution in one of the older answered questions, I would like to know why it does not work in this case.


I am using Ubuntu 14.04. How can I sync my OneDrive account on Ubuntu 14.04? I know that OneDrive is a Microsoft cloud storage service and that Linux is not  supported. But there is a a tool called "OneDrive-D".  How can install and use "OneDrive-D"?


Unlike rotations, the boost transformations are non-unitary. Therefore, the boost generators are not Hermitian. When boosts induce transformations in the Hilbert space, will those transformation be unitary? I think no. If that is the case, what is the physical significance of such non-unitary transformations corresponding to boosts in the Hilbert space?


Two apalike.bst file in unix texlive distribution: One in ./local/texlive/2016.. and other in ./share/texlive/

In trying to force the author name to be in capital letters in citation while keeping normal letters in the reference list. In this  there is an answer that suggests small changes in the file apalike.bst as a way to achieve this goal. Well, for my surprise, when I searching for the mentioned file through the folders of my linux distribuition, I got two matches instead of one. The two files apalike.bst are in the following paths:  ./local/texlive/2016/texmf-dist/bibtex/bst/base/apalike.bst ./share/texlive/texmf-dist/bibtex/bst/base/apalike.bst  From the exposed, my questions is:  What is the purpose to be two copies of this file?  Which one should I copy and change to achive what I want?  There is a better solution to work around this issue with natbib?


Where does the summation formula $(c^n - 1)/(c -1)$ come up? What does it apply to?

A solution I'm looking at employs this formula to find the sum of a finite series, but I haven't been able to find any information on this formula online or in my textbooks. Where does it come from, and what situations does it apply to? (It doesn't seem to be a reorganization of the formula for finite geometric sums...)


Replicate   Go to any question Click "close" to vote to close the question. Select "Off-topic". Click "Other (add a comment explaining what is wrong)". Click any other close reason.   Expected Results  The Vote to Close button should be enabled.  Actual Results  The Vote to Close button is disabled.  Work Around  Close the dialog and don't make a mistake the next time.


Object Oriented Python, if __name__ == '__main__'?

I am following a tutorial on wxPython and the tutorial shows the following code:  class Example(wx.Frame):      def __init__(self, parent, title):         super(Example, self).__init__(parent, title=title,             size=(350, 250))   def main():      app = wx.App()     ex = Example(None, title='Sizing')     ex.Show()     app.MainLoop()   if __name__ == '__main__':     main()   I am assuming   if __name__ == '__main__':         main()   is how the main() method is called but I am not really sure. Can someone explain what this bit of code does?


I have a code here that calculate a rate for payment. It works however certain value will result in numerous number of decimal points. I want the result to be converted into only 2 decimal point. How do I do this? below is the attached code:              double rateConv=(((new Double(4.4) * transaction.getAmount())/100)+(transaction.getAmount()+new Double(0.30)));                   System.out.println(rateConv);             transaction.setCurrencyPsy(rateConv);             transaction.setUserId(getLoginUserProfile().getUserId());             transaction.setTransType(WalletConstant.TRANS_DEPOSIT);             transaction.setIsApproved(false);             transaction.setCreateDate(new Date());             transaction.setIsCiTrans(false);             transDAO.save(transaction,getLoginUserProfile(),getText("email.admin"));             if(transaction.getDepositType().equals(WalletConstant.DEPOSIT_WIREDTRANSFER)){                 addActionMessage(getText("msg.success.tt"));             }else{                 addActionMsg(getText("msg.success"));             }             transaction = new WalletTransaction();         } catch (Exception e) {             e.printStackTrace();             addActionErr(getText("Error in system.Please contact system's administrator."));             return ERROR;         }                execute();         return "paymount"; }   Thanks in advance


prove or disprove that if a sequence does not have a converging subsequence then the sequence tend to infinity

how should I approach this?  "Prove or disprove that if a sequence does not have a converging subsequence then the sequence tend to infinity or negative infinity."


If $n > 0$ is an even composite integer, then $\varphi(n)$ is even?

If $n > 0$ is an even composite integer, is the corresponding totient $\varphi(n)$ also even?   I found that it is not the case for $n$ odd; for $\varphi(15) = 8$.


I have programmed my ATtiny1616 to output the clock on a pin.  Here is my reading:    Why is there all that ripple? How might I reduce it?


Why does this loop generate an error after the first conversion?

When I execute the program and I enter C or F and complete the process, this is the image of what I see:    I want to hide the line in the red rectangle. This is the code I have:  #include <stdio.h>  int main(void){     float f,c;     char var;     int x;      while(var!='x'){         printf("x=Ende c=Umrechnung c->f f=Umrechnung f->c:");         scanf("%c",&var);         if(var=='c'){             printf("Grad Celsius =");             scanf("%f",&c);             f=(c*1.8)+32;             printf("%.2f Grad Celsius sind %.2f Grad Fahrenheit\n",c,f);         }         else if(var=='f'){             printf("Grad Fahrenheit =");             scanf("%f",&f);             c=(f-32)/1.8;             printf("%.2f Grad Fahrenheit sind %.2f Grad Celsius\n",f,c);         }         else if(var=='x'){             printf("fertig !! chao\n");         }         else {             printf("Ungiltige Umreechnungsart!!\n");         }     }     return 0; }


5 random numbers were recorded: 100,32,76,52,17. If we know that these are elements of random sample took from set {1,2, ..., N}, how do we estimate the parameter N?


Standards of classifying a spell as an Unforgivable Curse

Three unforgivable curses are as follows:  1. Killing Curse  2. Imperius Curse  3. Cruciatus Curse  I just wanted to know if what are the standards of classifying a curse as unforgivable.


How to extract specific file(s) from tar.gz

How can we extract specific files from a large tar.gz file? I found  but, when I tried the mentioned command there, I got the error:  $ tar --extract --file={test.tar.gz} {extract11} tar: {test.tar.gz}: Cannot open: No such file or directory tar: Error is not recoverable: exiting now   How do I then extract a file from tar.gz?


How to change main query to only query posts from a single category?

I did create a custom page template and assigned to a page.  I have this code inside:  $news_filter = array(      'category'        => '53',      'posts_per_page'  => 5, );  $news = get_posts( $news_filter );  echo count ( $news );  foreach ( $news as $post ) :  setup_postdata( $post );     the_post_thumbnail();    the_title();    the_content();    endforeach;   It works, but I would learn more and more wordpress so, I would ask, if is there is a way to avoid having to run two queries? For example, I know existing of (custom) filter. Instead to make the loop twice (by WP and by me), can we add a filter, block WP and perform a custom loop?


Time duration between two time instances

Is there any method for getting duration between two time instances in hours and minutes ?


I have just started learning C from Ritchie and Kernighan's book. I am trying to reverse a string recursively, however, I get a segmentation fault with this code: #include <stdio.h> #include <string.h> void reverse (char s[], int l, int r);  int main () {       reverse("hello world", 0, 10); } void reverse (char s[], int l, int r) {           int temp = s[l];     s[l] = s[r];     s[r] = temp;          if (++l >= --r) {         return;     } else {         reverse (s, ++l, --r);     }     }  I'm not sure what im doing wrong, but I found that the segmentation fault occurs at s[l] = s[r];


Apparent bug with # of pending suggestion edits notification

On the , I am getting the pending suggested edit notice, but there aren't actually any I can approve.      The notice appeared right after I submit a tag wiki edit for approval, so the pending one is probably my own.  This didn't happen before I earned the "approve tag wiki edits" privilege, which I did happened today.  Thus, I think it is probably something having enough rep to approve the tag wiki but not enough to have the suggestion auto approved causes the system to think you should be able to approve it even though it is your own edit.


So I'm trying to get my laptops NVIDIA fx 880m to pass to a virtual box running window seven on a linux mint 17 install.  So far everything seems to be (maybe) heading in the right direction:  the device passed through happily, when I booted the virtual box it installed a bunch of new drivers, but when I try to install the NVIDIA driver on the guest it can't find the card. I looked under the device manager and there's no listing for the nvidia card under the pci bus, my guess would be that I need to disable it in the host so that it can be passed through to the guest (the virtual box manual said they can't be shared) but I'm not sure how to do so. Can anybody help with this? This question does not seem to me to be a duplicate of , because here the given solution was that it was not possible with a windows host, however in this case the host is linux


How to extrude inwards without leaving faces?

Here is the image to explain what i want    left box shows how i have set loopcuts (green is the face that i am extruding and moving). Middle one is what i want to get. The right is the issue with blender. the red faces will remain. (i have removed doubles on those faces) So is it possible to extrude inwards so that you dont have those faces hanging ? I know i could just delete those faces and thats it. but if you have lot of elements with similar idea it will get time consuming.  Thanks


From the Fourier transform we see that $L^2([0,2\pi])$ is isometrically isomorphic to $l^2(\mathbb{Z})$.  Is this true for other spaces and values of $p$ besides $p=2$?  What about if we ask about isomorphisms that are not necessarily isometric?


java.lang.NullPointerException error, how to fix?

when i run my program from the main i get the error on this line:  private class Node  I have a (circular) linked list class with a bunch of methods (only the first one shown here) and then a separate main.  I'd like to know what is causing this issue. Any help would be greatly appreciated. thanks.       public class CircleGame      {         //Node class (inner class)         private class Node         {             private int data;             private Node next;              //constructor of Node             private Node(int data, Node next)             {                 this.data = data;                 this.next = next;              }         }          /****************************************************/          private Node head;         int size =0;         int k = 0;         int s = 0;          //constructor of list         public CircleGame()         {             head = null;          }          /****************************************************/          public void addToEnd(int data)         {             //insert at beginning             if (head == null)                 head = new Node(data, null);              //insert at other positions             else              { Node temp = head;                 int i=0;                 while(i <size)                 {                      temp = temp.next;                     temp.next = new Node(data, head);                       i++;                 }             }              size ++;         }          /**************************************************/      //main     import java.util.*;  public class CircleGameMain {     public static void main (String [] args)     {         Scanner keyboard = new Scanner(System.in);         CircleGame game = new CircleGame();          System.out.println("***********WELCOME TO The CIRCLE GAME************");         System.out.print("How many players are in the circle? ");         int size = keyboard.nextInt();         System.out.println();         int data;          for(int i = 0; i < size; i++)          {             data = i+1;             game.addToEnd(data);         }          game.print();         System.out.print("What position would you like to start at? ");         int s = keyboard.nextInt();         System.out.println();          System.out.print("Eliminate the kth player. k= ? ");         int k =keyboard.nextInt();         System.out.println();         game.game(s,k);      } }


Delete invisible files on removable media

I have an external hard drive. macOS automatically saves files like ".Trash" and ".DS_Store" ".fseventsd". I was able to delete some files using the terminal. However, ".Trash" remained, which I cannot remove. What should I do? root@home Volume # sudo rm -rf .Trashes rm: .Trashes: Operation not permitted root@home Volume #


MacOS 'Big Sur' bad cpu type in executable error

I'm trying to follow along with this simple tutorial () to install Flutter SDK on my new MacOS. I reach step 3 which is to run the program "Flutter Doctor" by typing "Flutter Doctor" in the terminal. I am then greeted with the following error: /Users/Jake/documents/flutter/bin/flutter: line 183:  /Users/jake/documents/flutter/bin/cache/dart-sdk/bin/dart: Bad CPU type in executable  I've tried using different versions of flutter and still get the following error. I'm running a MacBook Pro with M1 if it helps. Edit: could apples new CPU be the issue?


Why do we start losing algebraic properties when dealing with hypercomplex numbers?

Every form of hypercomplex number I have seen (including the complex numbers) lose some important algebraic property. Why is that? Is there a pattern to what we lose?


Given that $\{\phi_n\}$ is a sequence of non-negative numbers whose sum is $1$ and $\{\psi_n\}$ is a sequence of positive numbers, how can I show that  $$ \prod_{n=1}^{\infty}~\psi_n^{\phi_n}~\leq~\sum_{n=1}^{\infty}~\phi_n\psi_n~? $$    Thanks.    PS: I'm not too sure about the title. Perhaps, someone could give it a better title?


How can I interpolate between two frames of a sprite-based 2D animation?

For example, I'm looking to animate at 60 frames per second, but clearly my artist isn't going to hand-author 60 frames of art for every second of an animation clip and even if he could, it would only work properly in locked-timestep.  So given two successive frames in a sprite-based animation, I want to smoothly "interpolate" or "morph" between them at runtime to produce a smoother, and higher frame rate animation based on where the update time for the current frame lies between the two frames.  Another way to look at it would be to say that my animation is authored such that the frames occur at regular intervals, much less frequent then 60 FPS. Say I'm 30% between when frame N should appear and when frame N+1 should appear. I want to render an image that looks like it's a 30% the way through a smooth transition from the frame N image and the frame N+1 image.  , but am interested in other potential solutions I could look at for implementing this. Please do not recommend a tool as a solution.


LED light fixture glows when not turned on

This past week at Menards I bought 2 Smart Electrician® 3650 Lumens 46" LED Linkable Shop Light Model Number: 0053-0011  |  Menards® SKU: 3481400.  The LED shop light fixture has a glow to it. Looked like the LEDs were turned on, but not all the way. The power switch is turned off. Don’t know why I did this but I took one of those three prong adaptors converters to two prong and to my surprise the light fixture didn’t light up. I unplug the cord with the adaptor and turned it around and it still didn’t light up. The power supply electronics inside the light fixture must be using the earth ground wire somehow. Using my volt meter. I measured to earth ground to the green wire that comes out of the adaptor and to my surprise depending how I plug in the adaptor. I’m getting 112 volts AC. That's because the adaptor isn't keyed and I'm switching the HOT and NEUTRAL around depending how I  plug it in.  I connected the LED light fixture to “Safety Analyzer tester”. When I press the “Open Ground” button, the fixture stops glowing (lightly lite LED’s).  Looks like the power supply circuit inside the fixture has a connection to “Earth Ground”.  I then switched the “Normal” on the polarity switch to “Reverse” and the LED’s were off. Switching the Neutral to open position has no effect. I'm thinking of taking them apart and see inside what's going on or take them back.  I figured out the problem.    In this light fixture you can clearly see the white wire (neutral/common) is connected to the light switch, turning the power off the LED light strip. Commonly we switch off the “HOT” to your light socket so when you change your bulb you have a less of a chance of getting electrocuted (that’s another story for later). Sometimes in Power supply circuits they place capacitors in there to help filter electrical noise out. Also known as suppressers (electronics to reduce unwanted noise or oscillation in a circuit or unwanted frequencies in a signal). Depending on how or where they are placed in the circuit it could possible cause some issue if not installed correctly or if the circuit isn’t designed correctly.   Since the BLACK live wire is connected to the LED PCB all the time, anything connected to that line will potentially be LIVE voltage, that way when I disconnected the earth ground from the socket and measured 112 volts on it. My guess is they have capacitors connected to both LIVE and NEUTRAL to the earth ground wire.  The current is flowing through capacitor C2, just enough to turn the LED’s on slightly. If the switch was on the hot side, this problem wouldn’t be happening. I still may use them just not connect the “earth ground” wire. Because that’s providing the return path for lighting the LED’s.


Showing graph nodes at various distance after pause in beamer


How do I get my -Project from View- image back in Blender v2.83?

We're doing a Motion Tracking project in class and we had to use Project From View for the UV on the building we intend to create the VFX meteor explosion, but when I went back into the Blender v2.83 file to continue my work, the picture is only a pink rectangle? (See below) Since it's a school project, I can't move into any higher versions of Blender, but need to work within this v2.83 only. Also, we're in Spring Break, so I'm unable to ask my teacher how to fix this, but I need to complete it this week. If anyone can help, please do, this is really the only part hanging me up as I do understand the rest of the assignment.  Thank you.


Are there more rational numbers than integers?

I've been told that there are precisely the same number of rationals as there are of integers. The set of rationals is countably infinite, therefore every rational can be associated with a positive integer, therefore there are the same number of rationals as integers. I've ignored sign-related issues, but these are easily handled.  To count the rationals, consider sets of rationals where the denominator and numerator are positive and sum to some constant. If the constant is 2 there's 1/1. If the constant is 3, there's 1/2 and 2/1. If the constant is 4 there's 1/3, 2/2 and 3/1. So far we have counted out 6 rationals, and if we continue long enough, we will eventually count to any specific rational you care to mention.  The trouble is, I find this very hard to accept. I have two reasons. First, this logic seems to assume that infinity is a finite number. You can count to and number any rational, but you cannot number all rationals. You can't even count all positive integers. Infinity is code for "no matter how far you count, you have never counted enough". If it were possible to count to infinity, it would be possible to count one step less and stop at count infinity-1 which must be different to infinity.  The second reason is that it's very easy to construct alternative mappings. Between zero and one there are infinitely many rational numbers, between one and two there are infinitely many rational numbers, and so on. To me, this seems a much more reasonable approach, implying that there are infinite rational numbers for every integer.  But even then, this is just one of many alternative ways to map between ranges of rationals and ranges of integers. Since you can count the rationals, you can equally count stepping by any amount for each rational. You can use 1..10 for the first rational and 11..20 for the second etc. Or 1..100 and 101..200 etc, or 1..1000 and 1001..2000 etc. You can map finite range of integers of any size to each rational this way and, since there is no finite upper bound to the stepping amount, you could argue there are potentially infinite integers for every single rational.  So... can anyone convince me that there is a single unambiguous correct answer to this question? Are there more rational numbers than integers, or not?  EDIT  Although I've already accepted an answer, I'll just add some extra context.  My reason for questioning this relates to the Hilbert space-filling curve. I find this interesting because of applications to multi-dimensional indexing data structures in software. However, I found Hilberts claim that the Hilbert curve literally filled a multi-dimensional space hard to accept.  As mentioned in a comment below, a one meter line segment and a two meter line segment can both be seen as sets of points and, but (by the logic in answers below), those two sets are both the same size (cardinality). Yet we would not claim the two line segments are both the same size. The lengths are finite and different. Going beyond this, we most certainly wouldn't claim that the size of any finite straight line segment is equal to the size of a one-meter-by-one-meter square.  The Hilbert curve reasoning makes sense now - the set of points in the curve is equal to the set of points in the space it fills. Previously, I was thinking too much about basic geometry, and couldn't accept the size of a curve as being equal to the size of a space. However, this isn't based on a fallacious counting-to-infinity argument - it's a necessary consequence of an alternative line of reasoning. The two constructs are equal because they both represent the same set of points. The area/volume/etc of the curve follows from that.


What does "knocks it out of the park" mean? Example: "All should read this book as it knocks it out of the park"


How to create frames as shown below with tcolorbox package. Although I did learn about it but did not know how to create the begging you help me thanks!


I had recently taken the hard drive out of my computer so that I could install a bigger one. But when I reconnected it to the computer, all the files on the E:\ partition and some of the files on the C:\ partition had strange names like TTv5yV5354$YVC5Wy on them. I did on one occasion move an electromagnet near the drive. Could that have caused this? Please help me, some of those files were valuable.


I'm leaning English and have a question about 'not for now'. Asked a friend of mine who got an argument, if I may ask her to go drinking sometime, and she told me 'not for now'.  This 'not for now' is confusing to me, it looks like she just turns me down, or I can ask her again in near future... :(  It would be highly appreciated if you teach me the exact meaning of 'not for now' in this sentence, because I don't want to bother her now... Thank you.


How can I contact a Slack team administrator if I'm not part of the team?

I wanted to register a Slack team, but the most obvious team name for my purpose is already taken and I can not imagine who in their right mind, apart from me, would want to use that name.   So I thought that perhaps this is one of those accounts that someone registered but did not end up using and I was hoping to contact the team administrator and ask whether they would be willing to give up the slack domain.  Unfortunately when I go to  [1] it says      This team's administrator has not enabled email signups.   So my question is: is there a way to contact the administrator and is there any precedent of giving up team domains?    [1] not the actual team name


How to handle regex syntax highlighting?

Many questions about regex include code blocks with language agnostic, POSIX compatible patterns, using default prettifying. ()  This looks kind of ugly and is confusing, since some parts are marked as literals. How should regex code be handled? Should syntax highlighting just be disabled for regex using lang-none? I think correct syntax highlighting could improve it's readability, just by marking meta-characters and escaped meta-characters. Including a language tag results in a different highlighting and seems superfluous when talking about POSIX regex - maybe even obstructive, since most people don't want to read questions about your . Including a language tag and using a full line of code, like String pattern = "[a-z0-9]+"; wouldn't add any valuable information. It would only get rid of the random highlights by showing the whole pattern as literal, so no advantage over disabling highlighting completely. Of course  has its advantage though and a new feature should wait imho until it is clear that a question's language tag .


Are there any differences between "Have been on a trip" vs "Have gone on a trip" and "Have gone crazy" vs "Have been crazy"?

Accourding to ,   We often use "been to" when we refer to completed visits to a place:  Have you ever been to Budapest?  Not: Have you ever gone to Budapest?  If the visit is not complete, we use "gone to".  Joan’s just gone to the shop. She’ll be back in about ten minutes. (Joan has not yet returned from the shop.)  Joan’s just been to the shop. She bought some cakes. Would you like one? (Joan has returned from the shop.)  Now, does that rule apply to the  "Have been on a trip" & "Have gone on a trip"?  So, "I have been on a trip" (I completed the trip & currently I am staying at home)  "I have gone on a trip" (I haven't completed the trip & currently I am on the trip)  And what about "gone crazy" & "been crazy".  Does "He has gone crazy" mean now he is still crazy?  Does "He has been crazy" mean now he is not crazy any more?  Are there any differences between "Have been on a trip" vs "Have gone on a trip" and "Have been crazy" vs "Have gone crazy"?  Note: I am not asking about "been to" or "gone to". I am asking about "been on a trip" & "gone on a trip". Do we apply the same rule of "been to" or "gone to" to "been on a trip" & "gone on a trip"?  Note2:  seems to prove that my thinking is right.


unable to boot to windows 8.1 after installing Ubuntu 14.10

I installed Ubuntu 14.10 today. But after completion of installation I'm not getting that dual boot screen. I mean its directly getting booted up to Ubuntu. I cant boot to Windows 8.1 What to do?? Please reply asap


What causes a "Rude or offensive" comment flag to sometimes cause instant deletion?

Sometimes a single "Rude or offensive" comment flag cause the comment to be instantly removed. What is causing this? This just happened to me, but I don't have the contents of the comment anymore. It included profanities, if that makes a difference.


Is there a word to describe an offensive term reclaimed by the offended group

Is there a word to describe the process, or result of the process of, an offended group reclaiming a word for themselves. For example, it is common for gay people to call themselves queers, or sexually liberated women to call themselves sluts, or black people to refer to themselves by various offensive terms.  I seem to remember there is a term for this process.  suggests "reappropriation" but I seem to remember there is a more specific term.


Taking password from a file while SSH ing into a machine

I want to SSH into a remote machine but instead of typing the password, I want to redirect it from another file.  So I have a file password.txt that stores the password. File.sh is my bash file.   In File.sh  #!/bin/bash ssh -T user@10.2.5.1   While executing the file, I did:  ./File.sh < password.txt   But I was asked to enter password anyway.   How do I get the password to be input from the file?


proof of $\sum_{i=k}^n {i \choose k}= {{n+1}\choose {k+1}}$ with another formula

I'm on an exercise for the university and have no clue what to do. The exercise is the following: You should proof that $\sum_{i=k}^n {i \choose k}= {{n+1}\choose {k+1}}$ . I've done that with an induction over $n$ and this goes very well.  But the other part is that we should use another formula an that is the following to proof it:  $$\sum_{i=k}^n {{i+1}\choose{k+1}} = \sum_{i=k}^n {i \choose{k+1}} + {i \choose{k}}$$  And there i need your help. Does anyone know what to do with this??  Thanks for your help!


Is that possible to run Ubuntu desktop installer from the existing iso on my hard drive?

I am runing debian 8 , i have a partition sd5 (100 GB ) ,Is that possible to install Ubuntu on sda5 from the existing iso without using cd or usb ?


How to write the complex number $z=-4-3i$ in polar form

According to the triangle that is formed in the third quadrant we have to calculate $ \tan (\alpha) = \frac {3}{4} $. How do I calculate the latter without using a calculator?


Can a dependent clause undergo inversion in English?

The grammars I've seen state that dependent clauses never undergo inversion. This agrees with sentences like     Tell me where he is.   But how sentences like     Tell me, where is he?   should be analyzed? Isn't where is he a dependent clause in this case?


Suppose $X$ is a normed vector space with norm $||\cdot||$. Suppose $S$ is a linear subspace of $X$ and $S$ is closed. Let $x\in X$. I was wondering whether the set $\{||x+s||: s\in S\}$ is closed in $\mathbb{R}$


How to get the current date and time to a certain format in python for GMT

What would be a good approach to getting the current date and time in the format below?  Mon, 25 Jul 2016 16:36:07 GMT   The date format must be exactly as per the HTTP-date header specifications - RFC 7231


Question regarding the validity of the big bounce

I have several questions regarding the "big bounce" theory. It appears to be popular among LQG researchers. My questions are as as follows.  1) How one reconciles it with the fact that it is now experimentally established that the universe is expanding in an accelerating manner?  2) The entropy of the universe should have been very very low (maybe zero) at the time of the big bang/ big bounce. What was the entropy "before" that event? Was it even lower? If it was lower then doesn't that mean entropy decreases indefinitely? On the other hand if we accept the entropy was higher then doesn't that violate the second law of thermodynamics?  3) What observational evidence can confirm pre-bounce physics? According to GR there are some points near the bang/bounce where one simply can't easily define time in a meaningful way. Even for a quantum gravity theory, is it possible for any theory to extrapolate itself "before" the "bounce"? If there are no observational consequences after the bounce shouldn't one apply Occam's razor?


Error : Could not resolve archive.ubuntu.com

I am getting this could not resolve issue. I have been on an open network from last two months after fresh installation of ubuntu 18.04. I have just shifted in a LAN with proxy. I have done every settings including updating the /etc/resolv.conf file and have looked at other solutions of these types. None is working.  sudo apt-get update Err:1 https://download.sublimetext.com apt/stable/ InRelease                      Could not resolve 'download.sublimetext.com' Err:2 http://security.ubuntu.com/ubuntu bionic-security InRelease                 Could not resolve 'security.ubuntu.com' Err:3 http://dl.google.com/linux/chrome/deb stable InRelease                      Could not resolve 'dl.google.com' Err:4 http://archive.ubuntu.com/ubuntu bionic InRelease                           Could not resolve 'archive.ubuntu.com' Err:5 http://ppa.launchpad.net/leaeasy/dde/ubuntu bionic InRelease      Could not resolve 'ppa.launchpad.net' Err:6 http://ppa.launchpad.net/maarten-baert/simplescreenrecorder/ubuntu bionic InRelease Could not resolve 'ppa.launchpad.net' Err:7 http://archive.ubuntu.com/ubuntu bionic-updates InRelease Could not resolve 'archive.ubuntu.com' Err:8 http://archive.ubuntu.com/ubuntu bionic-backports InRelease Could not resolve 'archive.ubuntu.com' Reading package lists... Done W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/bionic/InRelease  Could not resolve 'archive.ubuntu.com' W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/bionic-security/InRelease  Could not resolve 'security.ubuntu.com' W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease  Could not resolve 'archive.ubuntu.com' W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease  Could not resolve 'archive.ubuntu.com' W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/InRelease  Could not resolve 'dl.google.com' W: Failed to fetch http://ppa.launchpad.net/leaeasy/dde/ubuntu/dists/bionic/InRelease  Could not resolve 'ppa.launchpad.net' W: Failed to fetch http://ppa.launchpad.net/maarten-baert/simplescreenrecorder/ubuntu/dists/bionic/InRelease  Could not resolve 'ppa.launchpad.net' W: Failed to fetch https://download.sublimetext.com/apt/stable/InRelease  Could not resolve 'download.sublimetext.com' W: Some index files failed to download. They have been ignored, or old ones used instead.


I created an object but i would like to put a wood texture on it, how apply with blender 2.9?


Travelling to US with United Airlines with only one first name and only one last name

I'm flying for the first time to US with a passport. Until this day I always gave my first and last (João Martins - my full name is João Francisco Carvalho Andrade Martins) name for European flights and everything went great. While booking a flight to the US, I did the same, but I don't know if I should've done that.  My passport shows:     GIVEN NAMES: Joao Francisco      SURNAME: Carvalho Andrade Martins   But I just bought the tickets only with "Joao Martins". Am I in trouble?


Please explain why 1 4 5 6 is displayed for the last four echo statements?  I hit this by accident once, but I am now curious as to why this behavior occurs.  These statements work as expected (for me).  $ echo [ 9876543210 ]   [ 9876543210 ]  $ echo [237890]   [237890]   These echo statements consistently display 1 4 5 6.  Is there something special about these numbers?  $ echo [9876543210]   1 4 5 6  $ echo [abcd9876543210ghi]   1 4 5 6  $ echo [-123456-]   1 4 5 6  $ echo [-7654321-]   1 4 5 6   Thanks!   The possible duplicate is related and helpful, but not a duplicate. The possible duplicate is from the perspective of an rm command. This question is from the perspective of a perceived "weird behavior" of an echo command. The underlying answer for both is globbing. Someone searching for issues with an echo command would not easily find the rm question, but would more likely land here.


I installed the new version of QGIS 2.16 and I want to import an image (SVG file) as symbol for my point, but the setting style supports only xml format in import. Before, with an older version of QGIS, importing SVG files was possible.  How can I do this in the new version?      if i check svg symbol, I don't have the windows svg groups and images, my screen shot it's different


Rusty at complex integrals, finding error in steps

I am looking for some help spotting where I messed up some computations, it's been awhile... I'll show my work to my answer and then say what the correct answer is... Integrate: $$\int_0^{2\pi} \frac{\cos(3\theta)}{5-4\cos(\theta)}\mathrm{d}\theta$$  Let $z=e^{i\theta}$ for $0\leq \theta \leq 2\pi$. Then $|z|=1$ and  $$\cos(3\theta)=\frac{z^3+z^{-3}}{2}=\frac{z^6+1}{2z^3}$$ and  $$\cos(\theta)=\frac{z+z^{-1}}{2}$$ implies  $$\frac{\cos(3\theta)}{5-4\cos(\theta)}=\frac{z^6+1}{2z^3}\cdot \frac{z}{(-2z^2+5z-2)}$$ $$=\frac{z^6+1}{2z^2(-2z^2+5z-2)}=-\frac{z^6+1}{4z^2(z^2-\frac{5}{2}z+1)}=-\frac{z^6+1}{4z^2(z-1/2)(z-2)}.$$ Thus by the change of variable, $$\int_0^{2\pi} \frac{\cos(3\theta)}{5-4\cos(\theta)}\mathrm{d}\theta=\oint_{|z|=1} -\frac{z^6+1}{4z^2(z-1/2)(z-2)} \frac{\mathrm{d}z}{iz}$$ $$=-\frac{1}{4i}\oint_{|z|=1} \frac{z^6+1}{z^3(z-1/2)(z-2)} \mathrm{d}z.$$ Now obviously the poles of $f(z)=\frac{z^6+1}{z^3(z-1/2)(z-2)}$ are $z_0=0$, of order 3, and the simple poles $z_1=1/2$ and $z_2=2$. Only $z_0,z_1\in int \,\gamma$ where $\gamma=\{z\in \mathbb{C} : |z|=1\}$ (and $int \cdot$ is the interior of a set) thus by the Cauchy-residue theorem, we have $$\oint_{|z|=1} \frac{z^6+1}{z^3(z-1/2)(z-2)} \mathrm{d}z=2\pi i (Res(f,0)+Res(f,1/2)).$$  Now $$Res(f,0)=\frac{1}{2!} \lim_{z\to 0}\frac{\mathrm{d}^2}{\mathrm{d}z^2}z^3f(z)=\frac{1}{2}\lim_{z\to 0}\frac{\mathrm{d}^2}{\mathrm{d}z^2}  \frac{z^6+1}{(z-1/2)(z-2)}=\frac{21}{2}$$ by an elementary yet tedious calculus computation. I used wolfram alpha to be honest. Next, $$Res(f,1/2)=\lim_{z\to 1/2} (z-1/2)f(z)=\lim_{z\to 1/2}  \frac{z^6+1}{z^3(z-2)}=\frac{(1/2)^6+1}{(1/8)(-3/2)}=-\frac{65}{12}$$ Thus $$\oint_{|z|=1} \frac{z^6+1}{z^3(z-1/2)(z-2)} \mathrm{d}z=2\pi i\frac{61}{12}.$$ But, $$\int_0^{2\pi} \frac{\cos(3\theta)}{5-4\cos(\theta)}\mathrm{d}\theta=-\frac{1}{4i}\oint_{|z|=1} \frac{z^6+1}{z^3(z-1/2)(z-2)} \mathrm{d}z$$ $$=-\frac{1}{4i}2\pi i\frac{61}{12}=-\frac{61}{24}\pi.$$ However wolfram says the integral (in its original form) is equal to $\pi/12$. Where did I mess up?


How do I hand over a pointer to a non-static member method to an extern "C" function?

I've got a class named tmc, which now contains (among other things, which are not relevant here) a private constructor, a static factory method, and an instance method named ReadLoop (void*):  extern "C" { #include <pigpiod_if2.h> }  class tmc { public:   static tmc* Initialize ();   static int  main ();  private:   void *ReadLoop (void *params);   tmc ();   pthread_t *tmc_receiver_reader; };  tmc::tmc () : tmc_receiver_reader (start_thread (tmc::ReadLoop, NULL)) { }  void* tmc::ReadLoop (void *params) {   return params; }  tmc* tmc::Initialize () {   tmc* instance = new tmc ();   return instance; }  int tmc::main () {   return (tmc::Initialize ()) == NULL ? 0 : 1; }   The issue is now the following: How shall I use the ReadLoop as a function pointer for use with the  function contained in pigpiod_if2? The code shown here doesn't compile because of the following error:  error: invalid use of non-static member function ‘void* tmc::ReadLoop(void*)’    tmc_receiver_reader  (start_thread (tmc::ReadLoop, NULL))   I've seen several questions here at SO with the same error message, but none of them was about a pointer to a non-static member method given to a C function. Please note that even if the object created here is a singleton, I can't make ReadLoop () static. I'm using the g++ 6.5.0 on Raspbian Buster. Thank you.


If all Subgroups are Cyclic, is group Cylic?

I am having difficulty seeing if it is the case that if all subgroups of a group are cyclic, that the group itself is cyclic.


I want to put at the end of my bibliography a list of "suggested reading", that are NOT cited in the text but are present in the .bib file.  I use biber+bibtex with the numeric style. By using the \BibliographyCategory command I was able to create 2 categories and It works fine. The only thing I don't like is that the "suggested reading" are printed in the bibliography with the [number] on the left, and I don't want that, mainly because there's no citation of these in the document.  Here's a screenshot:    Is there any way I can remove the citation number only on the entries of a specific bibliography category?


How do favored classes work in Pathfinder?

I'm working on creating a half-elf paladin character for a Pathfinder game.  Full disclosure: this is the first time I've tried creating a character; I've used ones other people created before.  In the text, it mentions something about "favored classes" I believe.  What is this?


How to load and display a view with Ajax in Drupal 7?

This is the first time I've ever tried to load a view using Ajax in Drupal7 and I would be appreciated if you help me from scratch. I've spent hours to learn how to do this but I still failed!  I created a view called image_gallery, it has three blocks called hd,tablet and phone and it displays set of images.I created a tab and I want to display and load these blocks (generally views) with Ajax. this my HTML:

HD

Tablet

Cellphone

                 <?php print views_embed_view("image_gallery","hd") ?>

   I set the Use Ajax to "yes" in the views UI. this is my jQuery code:  $("#image_gallery_tab ul li").click(function(){         var id = $(this).attr("id").slice(-1);         $(".igc").css("display","none");         if(id==2)             {             $.ajax({                 url: Drupal.settings.basePath + 'views/ajax',                 type: 'POST',                 dataType: 'json',                 data: 'view_name=image_gallery&view_display_id=tablet', // Pass a key/value pair.                 success: function(response) {                   $("#igc2").innerHTML=response.display;                 },                 error: function(data) {                  alert('An error occured!');                 }               });             }     });   but it displays nothing. what is wrong here and what shall I do? thanks


Give a formal set theoretic argument to prove that, for all sets X, Y and Z, X \ (Y \ Z) = (X \ Y ) ∪ (X ∩ Z) .

Here is my question:     Give a formal set theoretic argument to prove that, for all sets $X, Y$ and $Z$, $$X\setminus(Y\setminus Z)=(X\setminus Y)\cup(X\cap Z)\;.$$   I know this is true, using the identity found , so I'm unsure how to answer the question as it appears to be an identity in itself?!  How do you think I should answer it?  EDIT: This is my final answer (thank you for your help). Is it correct?  //My interpretation of the half of your answer $$\begin{align*} &\text{Suppose }X\setminus(Y\setminus Z)\\ &\implies a\in X\setminus(Y\setminus Z)\\ &\implies a\in X\land a\notin (Y\setminus Z) &\quad\text{[Definition of complement]}\\ &\implies (a\in X\land a\notin Y)\lor (a\in X\land (a\in Y\land a\in Z)) &\quad\text{[distributive law]}\\ &\implies X\setminus Y\cup (X\cap Y\cap Z) &\quad\text{[associative law]}\\ &\implies X\setminus Y\cup (X\cap Y\cap Z)\subseteq X\setminus Y\cup (Y\cap Z) &\quad\text{[}A\cap B\subseteq A\text{]} \end{align*}$$  //My half of the answer  $$\begin{align*} &\text{Suppose }X\setminus Y\cup (X\cap Z)\\ &\implies a\in (X\setminus Y\cup (X\cap Z)) \\ &\implies a\in (X\setminus Y)\lor a\in(X\cap Z) &\text{[definition of union]}\\ &\implies (a\in X\land a\notin Y)\lor (a\in X\land a\in Z)&\text{[def of complement and intersection]}\\ &\implies a\in X\land (a\notin Y\lor a\in Z) &\text{[Distributive Law]}\\ &\implies a\in X\land (T\land (A\notin Y\lor a\in Z))&\text{[Identity]}\\ &\implies a\in X\land ((a\notin Y\lor a\in Y)\land (a\notin Y\lor a\in Z)) &\text{[Excluded middle]}\\ &\implies a\in X\land (a\notin Y\lor(a\in Y\land a\in Z)) &\text{[Distributive law]}\\ &\implies a\in X\land a\notin(Y\setminus Z) &\text{[Definition of complement]}\\ &\implies a\in X\setminus(Y\setminus Z)&\text{[Definition of complement]}\\ &\implies (X\setminus Y)\cup (X\cap Z) \subseteq X\setminus (Y\setminus Z) \end{align*}$$  Since A ⊆ B, and B ⊆ A, sets A and B are equal.


What's the known figures for the world population of magical humans? Further details, where available, is appreciated - population levels across geographical regions etc.


How many words can be formed from the letters of the word 'DAUGHTER' so that the vowels never come together?

How many words can be formed from the letters of the word 'DAUGHTER' so that the vowels never come together ?  The answer is obviously $8!-6!\cdot3!$.  My question is that if we ponder from a different perspective, that is taking $5$ consonants first and arranging them ($5!$ ways of doing that) and then placing the $3$ vowels in the $6$ places created due to the arrangement of consonants ($\frac{6!}{3!}$ ways to do that), the answer should be $5!\frac{6!}{3!}$.  What is wrong with this?


Install 12.04 on top of existing Linux Mint installation

This question has been answered before in many places but I just need some confirmation with my specific setup. I have Linux Mint installed and I just want a fresh Ubuntu 12.04 install to completely replace Mint. It's dual booted with Windows 7 and I want that to remain completely in tact.  Anyway, I'm currently running the Live CD installer. I've said I want to specify my own partitions and I'm at the following screen:     The list at the bottom expanded:     I confused by all the different partitions. Seems like I should just check the box beside sda5. But what about sda6? Do I just leave that alone?  Also just for confirmation, is the "right" way to replace Mint, or should I be deleting it first?


How to tell the compiler to user binary search

I am working on the algorithm of a project Euler problem. In this, I am processing a large list of numbers with possibly millions of entries in the list. I know beforehand that the list is sorted and I want to check if a particular element is in it or not. I can do it like:   if element in array:     #do something else:     # do something else   or like:   if((array.index(element)>=0):     # do something else:      # do something else   But I know it searches for the element linearly, which takes much time. It pains me that even if the list is sorted, it searches for it linearly. Is there a way that I can tell the compiler to search for the element using binary search, like a default parameter like:  if(array.index(element, binary_search=False):     #do something   so that I can make the second parameter to True and it works as expected. Or do I have to write the binary search function by myself and use it instead of the builtin index method or the in operator?   I am new to Python. Please bear with my ignorance. I searched for it extensively but couldn't find the exact answer. Thanks in advance.