How do I find other kids ages 12-14 to play Dungeons and Dragons with

I have been trying to find sites online, like  to find kids around my age to play d&d with, and that would mostly have a general idea of the game and rules, but no results.  One of the biggest issues is that I live in clarksville, and there aren't many people that are interested, while in a place like Nashville, several tabletop RPG group would let someone join with open arms.  The second biggest issue is that most friends and family would rather use their time playing fortnite and other video games and not take the time for what they think of a stupid and nerdy games that only losers play (except my father). I hope that the internet will have the answer, and know my fate depends on YOU.


Asymptotics of uniformly continuous functions over $\mathbb R$

For $\alpha >1$, $x^\alpha$ is not uniformly continous over $\mathbb R$ , essentially because $\forall \delta>0, \lim_n (n+\delta)^{\alpha}-n^{\alpha}=\infty$  I don't have a clear intuition about the behavior of uniformly continuous functions over an unbounded interval.      Is is safe to say that if $f$ is uniformly continuous over $\mathbb R$ then $\displaystyle \forall \alpha >1, f=o_{\infty}(x^{\alpha})$ ?


What is the logarithm of a kilometer? Is it a dimensionless number?

In log-plots a quantity is plotted on a logarithmic scale. This got me thinking about what the logarithm of a unit actually is.  Suppose I have something with length $L = 1 \:\mathrm{km}$.  $\log L = \log \mathrm{km}$  It seems that the unit of $\log L$ is $\log \mathrm{km}$, but I can also say $L = 1000 \mathrm{\:m}$ and now:  $\log L = 3 + \log \mathrm{m}$  This doesn't appear to have any units at all.  This suggests that $\log \mathrm{km}$ and $\log \mathrm{m}$ are actually dimensionless numbers. But wait, I can do this with any unit! Does it actually make sense to talk about the logarithm of a unit, or some other function for that matter?


How is it solved: $\sin(x) + \sin(3x) + \sin(5x) +\dotsb + \sin(2n - 1)x =$

The problem is to find the summary of this statement: $$\sin(x) + \sin(3x) + \sin(5x) + \dotsb + \sin(2n - 1)x =  $$  I've tried to rewrite all sinuses as complex numbers but it was in vain. I suppose there is much more complicated method to do this. I think it may be solved somehow using complex numbers or progressoins.   How it's solved using complex numbers or even without them if possible?  Thanks a lot.


Sometimes, when installing things its says "dependencies" are missing.    What are dependencies?


Get file extension from filename with php

I got the filename and path (gallery/thumbnail) where thumbnail can be png,jpg or mp4. it will always have the name "thumbnail" and i will always know the path.  How to find out what format the file is with php?  Edit.  I do not have the full file name (gallery/thumbnail.png) I only go the path without the extension (gallery/thumbnail.)  $fileName = "gallery/thumbnail.png' //file could be this $fileName = "gallery/thumbnail.jpg"; //or this $fileName = "gallery/thumbnail."; //but i only know this


does foreign key really slow the performance and better not to use it?

I'm trying to construct a database by using laravel relationships. As far as i know, foreign keys are a good way to ensure data integrity and correctness. Why not? I'd want to use it.   My questions are :  a)does using foreign keys in mysql really slow the performance at all? if yes, why does it slow?  b) If it slows, what should I do? Is it better not to use it at all ?


Problems when trying to uninstall Ubuntu 19.04 and install Windows 10

I am trying to remove Ubuntu 19.04 from a Lenovo Ideapad 320 laptop and convert it back to Windows 10. I have tried creating a Windows iso bootable USB but I have not been able to get the laptop to boot from this USB.   What I have tried is:  (I was unable to use Boot-Repair as it seemed 19.04 does not support it)  (In the first method the USB was recognized in the boot manager but it when selecting it it just opened normal Ubuntu; Installation failed on the Woeusb method )  I am wondering if anyone has any suggestions. I simply want to wipe this hard drive that contains only Ubuntu and reinstall Windows.   Thanks for the help guys. I have found that the easiest way to do it is to download the windows media creation tool that will make the usb for you. However you must use a windows computer to do this. To create this bootable USB without windows requires some workarounds in Ubuntu that I was not able to get to work.


Convergence of $\sum_{n=1}^\infty\frac{n!\, i^n}{n^n}$

I need to study this sum: $\sum_{n=1}^{\infty} \frac{n!\, i^n}{n^n}$. Taking: $$\lim_{n\rightarrow \infty} \; \left|\left(\frac{n!\: i^n}{n^n}\right)^{\frac{1}{2}}\right|$$ $$\rightarrow \lim_{n\rightarrow \infty}  \left|\left(\frac{n!}{n^n}\right)^{\frac{1}{2}}\right|$$  Using Stirling approximation considering the limit:  $$\ln n! \approx n \ln\:n-n$$ then $n! \approx (\frac{n}{e})^n$ (is this correct?):  $$\rightarrow \lim_{n\rightarrow \infty} \left|\frac{n}{n\, e}\right| = \frac{1}{e}$$ This doesn't make too much sense because I know the series diverges.  I think I'm missing a $\sqrt{2\pi n}$ in Stirling approximation but I don't understand why that pops out taking the $e^{(\;)}$ from the first expression.


How can I apply curve modifier to a mesh without it changing position?

Basically I have 3 meshes connected to each other I want them to rotate in the positions they are in but I also need them to bend at a certain point. The rotation is fine the problem is with the bending. The bending effect will be done with a curve modifier. The curve will change shape at a certain point and I'll save it as a shape-key. The problem is when I apply a curve modifier to one of the meshes and choose the curve that passes through the three meshes, the mesh changes position and messes up the whole thing. how do I apply a curve modifier while maintaining the position of the mesh I apply it to?


Problem: Prove there are no simple groups of order $1,000,000$.   So, I have used Sylow's Theorem to get that the number of Sylow $5$-subgroups is either $1$ (and we're done) or $16$.  I am assuming we have $16$, and let $H$ and $K$ be two of these Sylow $5$-subgroups. I'm trying to show $H \cap K$ is normal in $G$.  So, $|H\cap K| = |H||K|/|HK| > |H||K|/|G| \approx 244.14$  So since $H\cap K<H$, $|H\cap K|$ divides $|H|$. Thus, $|H \cap K| = 625$ or $3125$.  IF $|H\cap K| = 3125$, then $[H \cap K:H] = 5$ which is the smallest prime divisor of $15625$. So $H \cap K$ is normal in $H$ and normal in $K$. This forces $HK$ to be contained in the normalizer of $H \cap K$. Since the normalizer of $H \cap K$ is a subgroup of $G$, then its order must divide $G$. The size of $HK$ is $3125^2$, which is contained in the normalizer. So $3125^2$ must divide $1,000,000$. Contradiction.   So the normalizer of $H \cap K$ is all of $G$, and $H \cap K$ is normal.  I am completely stuck on what to do if $H \cap K$ has order $625$. Any help would be much appreciated.


How "smooth" is the evolution of the universe?

Mathematicians have developed different definitions for how "smooth" a function might be. A function (e.g. from or to $\mathbb{R}^n$ or $\mathbb{C}^n$) might be continuous, or once-differentiable, or twice-differentiable, or infinitely differentiable (smooth), or analytic. I am interested in the question of how smooth the evolution of the universe is. More precisely, for any physical theory, we can look at those trajectories in the relevant phase space (or configuration space) of that theory which conform to the laws of physics. For example, in classical mechanics, we can look at those trajectories in phase space that conform to Newton's laws. My question is the following: Can it be shown that every trajectory in phase space/configuration space that conforms to Newton's Laws (or Maxwell's Laws, or the Schrodinger equation) is continuous/differentiable/smooth/analytic? I realize this is a fairly open-ended question (because it asks about different laws of physics), but any partial answer would be appreciated.


geocoder = new Geocoder(MapsActivity.this);                 List<Address> addressList = null;                 try {                     addressList = geocoder.getFromLocation(firstLocationLattiutde, firstLocationlongitude, 5);                 }                 catch (IOException e) {                     e.printStackTrace();                 }                  Address obj = addressList.get(0);                 add = obj.getAddressLine(0);                 guardAddress.setText(add);   but sometime it give error like this     java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.Object java.util.List.get(int)' on a null object reference at com.example.fahadaziz.securityapplication.Services.MyService.onLocationChanged


What is the best place to ask for help, and tips, on designing a web application?

I'm new to web applications, and have some broad questions about designing a back end, and model view controllers. Where is the best place to ask?


A $\log \Gamma $ identity: Where does it come from?

$$\log \Gamma (n)=n\log n -n +\frac{1}{2} \log \frac{2\pi}{n}+\int_0^\infty \frac{2\arctan (\frac{x}{n})}{e^{2\pi x}-1} \,\mathrm{d}x$$  Is an identity that is derived from using Sterling's approximation. I can't quite figure out how it was used, and was wondering for a proof.


Unusual behavior logging in to stackexchange.com only (not other SE sites)

When I am logged in to one SE site, then type the url for another derivative SE site in a new tab, I'm already logged in there as usual.  However, when I type stackexchange.com I see the page not logged in.  Curiously though, if I click Log In, I get what looks like the Sign Up page.  And if I click Sign Up, I get a white page with a long url as text:  THe page's url is https://stackexchange.com/users/signup?ssrc=head&returnurl=https%3a%2f%2fstackexchange.com and the text shown on the page (I've truncated it in case there might be some security reveal in the code: https://openid.stackexchange.com/affiliate/form?affId=11&background=transparent&callback=https%3a%2f%2fstackexchange.com%2fusers%2fauthenticate&color=black&nonce=%2brsQWgAAAADlmwDRpG5zEQ%3d%3d&openid.sreg.requested=email&signupByDefault=true&onLoad=loaded&authCode=u%2bdDP1cFtRe5N13hdCOFt6EOZK2w5371%2bLZFRpDf0jtqjwV24gUVxhe%2fE1OUr52WthdUSh3FCX one hundred characters deleted    Screen shot of what looks like a sign up page that appears when I click Log In:        Screen shot of white page with url text that appears when I click Sign Up (truncated):


How can I set a script to run a newline is added to the end of a file?

I have a file called alarm.log, and I want a script to automatically run when this file is changed.


Is reimbursement of a brokerage transfer fee taxable income?

I switched the brokerage for a taxable investment account last year. The new brokerage reimbursed the transfer out fee of $50 from my old brokerage. I don't have my 1099s yet but I noticed in the online tax information at my new brokerage, it has that $50 as taxable income. Is this correct? Since it's a reimbursement it doesn't seem like it should be. Unless perhaps my old brokerage would put -$50 on my 1099 from them? That seems unlikely though.


Programmatically Dial a Phone number and pass DTMF using the iPhone SDK

How do you programmatically do the following from the iPhone SDK:   Programmatically Dial a Phone Number through the iPhone SDK Bypass the dial / cancel prompt that the iPhone brings up Send additional DTMF after the number is dialed just like how you would program pauses into a regular phone.    I know you can make a tel:// call but the issue is that it brings up the dial / cancel prompt and after that it prevents any future DTMF from being sent.


How can i turn a few Planes upside down?

Im currently modeling a 3D Character in Blender. Im learning from a Video Tutorial Serires of Darrin Lile on Youtube, because im a total Blender Noob. I finished the surface of my Character using Planes. But now half if my Blender figure is covered in Shadows/Dark (?). Its really hard to describe that, especially when youre not a native speaker so here are some screenshots.   PLS HELP. Thank you :D


How can I move files and view the progress (e.g. with a progress bar)?

When moving large directories using mv, is there a way to view the progress (%)? The cp command on gentoo had a -g switch that showed the progress.


Show that a given analytic function is constant

Let $f:\mathbb{\Omega}\to\mathbb{\Omega}$ be an analytic function such that there exist $z_0$ and $z_1$ $\mathbb{R}$-linearly independent$f(z+z_0) = f(z)$ and $f(z+z_1) = f(z)$ for all $z$. Show that $f$ is constant.  I can show that $f(nz_0+mz_1) = f(0)$ for $n$ and $m$ natural numbers, and I know that if  I could show it for $n$ and $m$ rational, it will be enough to conclude. But I'm not really sure how to continue or whether that's the right way or not (maybe I could use the maximum modulus principle o some similar theorem). Any help will be appreciated


Can a Dragon really also be Half-Dragon?

I was playing D&D 3.5 when it was pointed out to me that the half-dragon template can be added to any living corporeal creature which includes dragons. That seems really weird — how can a creature be half of something it already is?  Can a dragon really have the half-dragon template applied? Is there any official errata saying it can't?


Every time I get an email message in Gmail, the notification bar shows me 3 notifications instead of one: the first labeled important, the second labeled priority inbox, and the third is the regular one. How do I get only one notification and make my incoming mail regular/normal, without the auto-label important or priority?


Probabilistic predictions from a frequentist point of view

I'm trying to understand how a frequentist would approach statements like "having observed X, the probability of Y happening is Z". For concreteness, let's say we conducted $n_1$ identical, independent Bernoulli trials, and observed $n_1$ successes and 0 failures. We want to attach a probability to the statement "the next $n_2$ trials will also all succeed". The Bayesian approach is straightforward: choose a prior for the Bernoulli parameter $p$, let's say a Beta distribution $\mathrm{Beta}(\alpha, \beta)$, incorporate the likelihood of the first $n_1$ observations to obtain a posterior, then compute the expected value of the probability of $n_2$ additional successes according to the posterior. If I'm not mistaken, the result is: $$\text{Prob}(\text{$n_2$ additional successes}) = \frac{B(\alpha+n_1+n_2, \beta)}{B(\alpha+n_1,\beta)}$$ I'm less sure about how a frequentist would look at the problem. Here is what I think. We decide a priori that we are going to make our claims according to the following decision tree:  If there is any failure in $n_1$ trials, then make no claim.  If there are no failures in $n_1$ trials, then claim that there will be no failures in the next $n_2$ trials.   The probability that this decision tree will lead to make an incorrect claim is: $$\text{Prob}(\text{incorrect claim}) = p^{n_1}(1-p^{n_2})$$ and this probability is maximized if the Bernoulli parameter is $$p_{\text{worst case}} = \left( \frac{n_1}{n_1+n_2}\right)^{\frac{1}{n_2}}$$ So the probability of making an incorrect claim, in the worst case scenario, is: $$\text{Prob}(\text{incorrect claim, worst case}) = \frac{n_2}{n_1+n_2}\left(\frac{n_1}{n_1+n_2}\right)^{\frac{n_1}{n_2}}$$ And this would lead me to conclude that, from a frequentist point of view: $$\text{Prob}(\text{$n_2$ additional successes}) =  1 - \frac{n_2}{n_1+n_2}\left(\frac{n_1}{n_1+n_2}\right)^{\frac{n_1}{n_2}}$$ Here the meaning of the probability is that if the experiment is repeated many times, for every time that the decision tree leads to claim there will be $n_2$ additional successes, the claim will wrong at most this fraction of the time, regardless of the true value of $p$. I am suspicious of this approach mainly because it appears to be less conservative than the Bayesian, for any reasonable choice of the prior.


Extended permutations, how does it work mathematically if you keep adding categories?

I'm a little bit unsure how to approach this problem of permutations when you add categories:  Each object can contain 3 attributes out of the 10 possible available.  Because order doesn't matter, there would be 10 x 9 x 8 = 720 possible choices. If duplications of attributes don't matter (eg. you can have 3 of the same attribute), then there will be 10 x 10 x 10 possible choices. This part is easy.  But what I don't understand, is what happens if this object can randomly come from any of 30 countries?  And what if this object can be of any 5 sizes?  How many possibilities are there?


getting all values for a custom field key (cross-post)

I know how to get a custom field value for a specific post.   get_post_meta($post_id, $key, $single);   What I need is to get all the values associated with a specific custom post key, across all posts.  Anyone knows of an efficient way to do this? I wouldn't want to loop through all post id's in the DB.  Example:  4 posts all with different values for a custom field called 'Mood'. 2 posts have the value 'happy', 1 post have 'angry' and 1 post has 'sad'  I want to output : across all posts we have: two happy, one angry and one sad author(s).  But for LOTS of posts.  What I'm looking for is either:   a WP function to get this. or a custom query to get this as efficiently as possible.


Story identification: Quantum tunnelling let everyone see anything and anywhere in the past

Knowing my luck I'm again asking for something obvious like Harry Potter or LOTR but hey, Google hates me...  It was a story that I've read about early 2000s and the story was describing social changes in the society caused by a new way of data transmission via "quantum tunnelling".   This technology was initially developed as a mean to send information almost instantaneous over long distances and involved creating a tiny portal on the sender and receiver end, that allowed to transfer electromagnetic waves.  Soon after, this invention has been upgraded and started allowing to see also events in the past.  Initially, this technology was held only by a giant telecommunication agency (and rented to government and press) but thanks to a leak it became widespread to population, that started using implants allowing everyone to see any events that has happened almost whenever in time: privacy, secrecy almost ceased to exist, since without much effort you could see not only your neighbour changing but also JFK having sex with Marilyn Monroe (and then see from dozen angles who actually shot him on who's order etc.). Getting away with crimes also became impossible, since police could clearly see "whodunit", although people started to commit low-level crimes (like littering) on purpose, as a strange way to annoy the ever-watching Big Brother.   One of the plots involved an old crime - father of the family of two has been convicted and executed for killing his son, while the real culprit was his mentally unstable daughter. Blaming the quantum tunnelling inventor for the loss of her whole family (because he didn't invent it before the execution and because review of the crime found the real murderer) wife of the executed guy starts plotting to kill him.  This book must have been written some time post cold-war era, I remember that it mentions Russia (not USSR) and the Internet


Condition on p for convergence of $\sum{\frac{1}{n(\log(n))^p}}$

For what values of $p$ is the series $\sum{\frac{1}{n(\log(n))^p}}$ divergent and for what values it is convergent?


How would you describe a sound "appearing"?

The idea behind something appearing is more visual in nature; it comes into sight.  What would I say if something "appeared audibly"? The sound of the oncoming car appeared to my ears!   all seem to stick to visual, material, or abstract concepts; nothing for auditory elements stand out.


$f$ is bounded and continious $\Rightarrow$ the convolution integral $\int f(\tau)g(x-\tau)\text{ d}\tau$ is bounded and continuous

Let $g\in L^1(\mathbb{R}^n)$ and $f:\mathbb{R}^n\to\mathbb{R}$ be bounded and continuous. Why is the convolution integral $$f*g:\mathbb{R}^n\to\mathbb{R}\;,\;\;\;\int f(\tau)g(x-\tau)\text{ d}\tau$$ also bounded and continuous?  *Proof*$\;\;\;$ It holds $$|(f*g)(x)|\leq\int |f(\tau)g(x-\tau)|\text{ d}\tau =\int |f(x-t)g(t)|\text{ dt}\le \sup_{x\in \mathbb{R}^n}|f(x)|\int |g(t)|\text{ dt}$$ Since $f$ is bounded and $g$ is integrable the supremum and the integral exists. This should be enough for at least the boundedness of $f*g$. While I would like to be sure that this is correct, I would also like to know how we show the continuity.


I think an update may have created a network problem on Artful ardvark. How do I delete the last update? I can't connect to a network to update any patches.  I can not connect to a wireless network. I used to be able to connect and then a few days ago it started disconnecting and reconnecting. After that it would no longer connect. I could connect to a wireless printer and print. I need solutions that don't include connecting to the internet to update or get any packages as I can't do either.


How to make a digital comparator with multiple inputs?

I have been attempting to make a digital comparator but I am struggling to get in more than one input. The idea is that I have 2 sets of 2 numbers (4 inputs total) and I want to have the output take all 4 numbers into account rather than just 2. Here is what I roughly have so far:    What I want the circuit to do is have the two inputs in the two sets treated as separately. Any ideas on how to achieve this would be very welcome.


How do I check where devices are mounted?

What is the command that lets me see what and where devices are mounted?  I'm having trouble changing songs on my old iPod, and I have a feeling it's because of the mount point.


i just installed ubuntu 14.04 and when i'am connected with wifi i can't post or register on any site or forum there is no problem when iam using wired connection  i've got broadcom 43142


Unable to install any updates through update manager/apt-get upgrade

I have been running Ubuntu 12.04 for the past few weeks. I recently tried to download and install some files through the Update Manager. It located a few files, downloaded them, but then failed to install them. It gave the error:  installArchives() failed: (Reading database ...  (Reading database ... 80% dpkg: unrecoverable fatal error, aborting:  reading files list for package 'libasn1-8-heimdal': Input/output error   I tried using apt-get upgrade but a similar error was produced:  Reading package lists... Done Building dependency tree        Reading state information... Done The following packages will be upgraded:   icedtea-6-jre-cacao icedtea-6-jre-jamvm openjdk-6-jre openjdk-6-jre-headless   openjdk-6-jre-lib 5 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B/34.6 MB of archives. After this operation, 1,024 B of additional disk space will be used. Do you want to continue [Y/n]? y (Reading database ... 80% dpkg: unrecoverable fatal error, aborting:  reading files list for package 'libasn1-8-heimdal': Input/output error E: Sub-process /usr/bin/dpkg returned an error code (2)   Any help would be greatly appreciated. Thanks in advance.  Edit: Here's some extra information that may be useful. My original problem was that the Ubuntu Software Centre would not open. I found that the Update Manager and Synaptic Package Manager also failed to open. They all gave an error along the lines of:   "installArchives() failed: dpkg: error: reading package info file '/var/lib/dpkg/available': Input/output errorError in function:"   After much googling I seemed to fix that problem as the package managers would open again. When I then tried to download and install any updates from the Update Manager I got the error at the beginning of this post.


So I have been searching for a simple example to hopefully a simple problem.  I have a simple object a List of ListTest (List)  public class ListTest{ {     public string perName { get; set; }     public string perSex { get; set; }     public ListTest(string pName, string pSex)     {         this.perSex = pSex;         this.perName = pName;     } }   I have loaded it with some data:          List<ListTest> tryIt = new List<ListTest>();         tryIt.Add(new ListTest("Karen", "F"));         tryIt.Add(new ListTest("Kate", "F"));         tryIt.Add(new ListTest("Glen", "M"));         tryIt.Add(new ListTest("Tiger", "M"));         tryIt.Add(new ListTest("Clementine", "F"));         tryIt.Add(new ListTest("Magnolia", "F"));   Now I want to query it using a Lambda Expression:          var things = tryIt                      .Where(sex => (sex.perSex == "F"))                      .OrderBy(sex => sex.perName);   But I want to do it dynamically, just in case I want to change my where to "perName".  I am able to create the Lambda Expression your Expressions, but I can't figure out how to take it across the goal line and actually assign it to a where clause and execute it.          IQueryable<ListTest> iq = tryIt.AsQueryable();         ParameterExpression pe = Expression.Parameter(typeof(ListTest), "Person");         Expression paEx = Expression.Property(pe, "perSex");         Expression right = Expression.Constant("F");         Expression eqEx = Expression.Equal(paEx, right);         Expression lE = Expression.Lambda<Func<ListTest, bool>>(eqEx, pe);   This should be a simple 4 or 5 line solution, but I can't find an easily decipherable solution example.  Should I use a MethodCallExpression or something down those lines?  Thanks,


Windows Defender: Disable real time; keep scheduled and on demand scanning

I just upgraded to Win 10 (RTM build). I have disabled the built in AV's (Defender) real time protection because I do not run it, never did and have never gotten a virus (and I've had a computer for 30 years).  I was able to disable real time scans by turning on the Group Policy's Disable Defender Policy. But this disables the application entirely. Is it possible to use this profile (which I used with Win 7's Security Essentials) with Win10 Defender:   Real time scan off Scheduled scans (2AM) active On demand (shell integration right click) scans active   ?  Or do I have to install a 3rd party scanner? I already run  Premium,  and  (those are protecting in real time, as their impact on performance is minimum), but I would really like to avoid a 3rd party AV.  TIA


What is the metric tensor describing spacetime around an infinitely long rod?


How can I redirect the contents of a file to the pastebinit command?

Whenever I was to store something to show someone here, I run  command-with-output | pastebinit.   That returns the link to the paste online. For example:  echo sometext | pastebinit   gave me the link    Which I can share. How can I do this with a file - for example a log file. Surely I don't have to open - > copy all - > open paste.ubuntu.com -> paste it?


What are the “savings” one makes by choosing a server install over a desktop?

I’ve been using 18.04 server for several months to host a few services.  I’ve recently started diving into Docker and in many of the guides I encounter they give command line calls that use NetworkManager, which is not installed with server.  This is annoying to the point I’m asking myself why I’m not using Desktop.  I chose the server flavor mostly because I like the geekiness of the command line.  I also figured it is less resource intensive than its Desktop counterpart.  I know I can install Desktop and still use the command line, but what am I “saving” by using Server over Desktop, especially if both versions use the same kernel?  If I’m using the machine as a server, how much is Desktop costing me in terms of resources and performance?


I am trying to achieve the effect bellow (source: Twitter official blog header image).  I have a background color and a few colorful flat objects that I want to bend into the background color like bellow.


How can i only shine/shoot one proton/electron per second?

I would like to test out the two slit experiment but only one electron or proton at a time.   This question is different from the rest that people are saying are duplicates as I am clearly asking how can "I" shine/shoot one proton/electron per second? The answer clearly explains how I can do this. I am not tring to understand how it works, or see experiments, im asking how it is possible for "me" to do it. As you can see from my accepted answer.


I'm looking for a place in Brussels where I can leave my luggage (It's 28 inch suit case) for about 10 days. I found Brussels Midi train station offers storage but not sure if it offers it for such a long time.  Is it possible to store it long term at Midi train station or are there other alternatives?


In a case study  Scattering of light affects the image captured by camera.  Now how to write  The scattering affected image...  Or  The Scattering effected image...  And  Image affected by scattering  Or  Image effected by scattering...  Which one is correct?


How to browse the server to upload files from there in Drupal 7

I need to upload the audios and videos on server in a specific folder via FTP and then let the content managers to select them when they want to upload any of them in add/content path (because it takes a long time to upload them via the Add Content user interface). Is there such a capability in Drupal 7?


I have tried the code:  \begin{thebibliography}{0} \bibitem{item1} author 1 and author 2 \textit{The title}. Thesis. SchoolName, 2018. \end{thebibliography}   It outputs "References", but since I am using only one reference, I want to use "Reference"; that is, without the "s".  EDIT I used \documentclass{article}. What worked for me was using  \renewcommand\refname{Reference}


MacBook Pro's battery charging only to 27%

I have a 2017 15" MacBook Pro.  A while ago I posted question related to issues with battery here:      What's funny is that that problem solved itself eventually (The next day it charged as expected). Two weeks later I kinda got into the same problem, but now it charges only to 27%.  Interestingly, I don't have any performance problems if I am on battery and the battery usage is normal.  If someone has experienced similar problems, I am curious to know if they have done something to fix it. I have tried resetting the SMC multiple times but to no avail.


I noticed Blender 2.79 doesn't show the "save & reload" option anymore.  I used to use that to clear any unused materials.  How can I do this?  I tried making all objects single users, the orphan add-on, nothing seems to work.


$x,y,z$ independent and uniform random on $[0,1]$, $P(x \geq  yz)$?

$x,y,z$ are independent and uniform random on $[0,1]$.  I know that $P(x \geq yz) = 3/4$ by triple integrating the triple density function.  However, is there a easier way to get this solution? Without triple integration.


Difference between loss functions in neural networks

Supose I would like to build a neural network with a sigmoidal function in the output layer, why is there a preference in the use of cross-entropy as a loss function in regard square loss for example? I can understand that in a simple logistic regression the cross-entropy would make the loss a convex function but in neural networks the domain is always non convex, so why the preference?


[root@datacenteronline ~]# ssh root@192.168.1.172 Last login: Wed Apr 17 09:55:45 2013 from 192.168.1.187 [root@localhost ~]# ls /proc/ | grep 2266 [root@localhost ~]# cd /proc/2266 [root@localhost 2266]# ls attr             cpuset   limits      net            root       statm autogroup        cwd      loginuid    numa_maps      sched      status auxv             environ  maps        oom_adj        schedstat  syscall cgroup           exe      mem         oom_score      sessionid  task clear_refs       fd       mountinfo   oom_score_adj  smaps      wchan cmdline          fdinfo   mounts      pagemap        stack coredump_filter  io       mountstats  personality    stat [root@localhost 2266]# ls -al /proc/2266 total 0 dr-xr-xr-x   7 apache apache 0 Apr 17 09:45 . dr-xr-xr-x 266 root   root   0 Apr 17 09:11 .. dr-xr-xr-x   2 apache apache 0 Apr 17 09:45 attr -rw-r--r--   1 root   root   0 Apr 17 09:45 autogroup -r--------   1 root   root   0 Apr 17 09:45 auxv -r--r--r--   1 root   root   0 Apr 17 09:45 cgroup --w-------   1 root   root   0 Apr 17 09:45 clear_refs -r--r--r--   1 root   root   0 Apr 17 09:45 cmdline -rw-r--r--   1 root   root   0 Apr 17 09:45 coredump_filter -r--r--r--   1 root   root   0 Apr 17 09:45 cpuset lrwxrwxrwx   1 root   root   0 Apr 17 09:45 cwd -> / -r--------   1 root   root   0 Apr 17 09:45 environ lrwxrwxrwx   1 root   root   0 Apr 17 09:45 exe -> /usr/local/apache2/bin/httpd dr-x------   2 root   root   0 Apr 17 09:45 fd dr-x------   2 root   root   0 Apr 17 09:45 fdinfo -r--------   1 root   root   0 Apr 17 09:45 io -rw-------   1 root   root   0 Apr 17 09:45 limits -rw-r--r--   1 root   root   0 Apr 17 09:45 loginuid -r--r--r--   1 root   root   0 Apr 17 09:45 maps -rw-------   1 root   root   0 Apr 17 09:45 mem -r--r--r--   1 root   root   0 Apr 17 09:45 mountinfo -r--r--r--   1 root   root   0 Apr 17 09:45 mounts -r--------   1 root   root   0 Apr 17 09:45 mountstats dr-xr-xr-x   6 apache apache 0 Apr 17 09:45 net -r--r--r--   1 root   root   0 Apr 17 09:45 numa_maps -rw-r--r--   1 root   root   0 Apr 17 09:45 oom_adj -r--r--r--   1 root   root   0 Apr 17 09:45 oom_score -rw-r--r--   1 root   root   0 Apr 17 09:45 oom_score_adj -r--r--r--   1 root   root   0 Apr 17 09:45 pagemap -r--r--r--   1 root   root   0 Apr 17 09:45 personality lrwxrwxrwx   1 root   root   0 Apr 17 09:45 root -> / -rw-r--r--   1 root   root   0 Apr 17 09:45 sched -r--r--r--   1 root   root   0 Apr 17 09:45 schedstat -r--r--r--   1 root   root   0 Apr 17 09:45 sessionid -r--r--r--   1 root   root   0 Apr 17 09:45 smaps -r--r--r--   1 root   root   0 Apr 17 09:45 stack -r--r--r--   1 root   root   0 Apr 17 09:45 stat -r--r--r--   1 root   root   0 Apr 17 09:45 statm -r--r--r--   1 root   root   0 Apr 17 09:45 status -r--r--r--   1 root   root   0 Apr 17 09:45 syscall dr-xr-xr-x  29 apache apache 0 Apr 17 09:45 task -r--r--r--   1 root   root   0 Apr 17 09:45 wchan   Cound anyone tell me what it is?


Proving that $\frac{1}{1\cdot 2} + \frac{1}{2\cdot 3} + \frac{1}{3 \cdot 4} +\ldots + \frac{1}{n(n+1)} = \frac{n}{n+1}$

How would we go about proving that $$\frac{1}{1\cdot 2} + \frac{1}{2\cdot 3} + \frac{1}{3 \cdot 4} +\ldots +\frac{1}{n(n+1)} = \frac{n}{n+1}$$


How to take the night skies and meteor showers?

I have a Nikon D5200 and last night I went to take few night sky pictures hoping to capture a passing meteor. There were plenty of meteors I seen last night, but I was able to capture only one. Question is, I keep on seeing those amazing pictures of the sky and of passing meteors, how can I take them?   I took the following pictures on Manual mode. The ISO was set to 600 I think, Aperture was 4.0 or 4.5 and the Shutter Speed was set to Bulb and I gave it roughly 20-40 seconds. The camera was mounted on tripod and I did not extend the legs. It was not windy, but I was on the shore. The pictures were taken (start and end) with a remote control so the camera was not touched. However, the pictures seen to be unfocused and smudgy. What can I do to improve the picture's quality?  The third picture here shows the one faint meteor passing (there is a second one on its left, but its even fainter).


Python - while loop returns print across?

how do I make the result below print on a single line instead of down the column? Thanks. i = 3 while not i<=0:     i-=1     print(i)  expected: 2 1 0


How to show 4  on one row and the others 4  on the other one

I have the query on php which takes a lot of images from database, I need to show 4 images on the first row, the other 4 images on the next row and so on.  I thought I could do that with the help css, but I can't =(  HTML  <div id="photo_block" style="border:2px dotted <?echo $color;?>; height:1000px;" >      <?         while ($item=$select_items->fetch()) {     ?>

             <img src="<?echo $item['src']?>">

      <?         }     ?>
   CSS  #photo_block{     width:800px; } .items li{     display: inline; } .items li .item_block img{     width: 100px;     height: 100px; }   thank you for helping me!


If I have 3 domains, domain1.com, domain2.com, and domain3.com, is it possible to set up a default virtual host to domains not listed? For example, if I would have:  <VirtualHost 192.168.1.2 204.255.176.199> DocumentRoot /www/docs/domain1 ServerName domain1 ServerAlias host </VirtualHost>  <VirtualHost 192.168.1.2 204.255.176.199> DocumentRoot /www/docs/domain2 ServerName domain2 ServerAlias host </VirtualHost>  <VirtualHost 192.168.1.2 204.255.176.199> DocumentRoot /www/docs/everythingelse ServerName * ServerAlias host </VirtualHost>   If you register a domain and point it to my server, it would default to everythingelse showing the same as domain3. Is that possible?


Prob. 13, Sec. 30, in Munkres' TOPOLOGY, 2nd ed: Every collection of disjoint open sets in a separable space is countable

Here is Prob. 12, Sec. 30, in the book Topology by James R. Munkres, 2nd edition:     Show that if $X$ has a countable dense subset, every collection of disjoint open sets in $X$ is countable.   My Attempt:     Let $D$ be a countable dense subset in the topological space $X$. Then $D \subset X$ and $\overline{D} = X$.      Let $\mathscr{A}$ be a (pairwise) disjoint collection of open sets of $X$.       For each $A \in \mathscr{A}$, we must have $$ A \cap D \neq \emptyset, $$   by Theorem 17.5 (a) in Munkres; let us choose a point $x_A \in A \cap D$.      Now if $A_1$ and $A_2$ are any two distinct sets in $\mathscr{A}$, then since $A_1 \cap A_2 = \emptyset$, therefore we must also have   $$  \left( A_1 \cap D \right) \cap \left( A_2 \cap D \right) = \left( A_1 \cap A_2 \right) \cap D = \emptyset, $$   which implies that   $$ x_{A_1} \neq x_{A_2}. $$   [Please refer to the preceding paragraph.]      Thus the map $\mathscr{A} \rightarrow D$, $A \mapsto x_A$ is an injection of $\mathscr{A}$ into the countable set $D$. Therefore the collection $\mathscr{A}$ must be countable.   Is this proof correct and satisfactory enough? Or, are there any lacunas?  Here I have assumed that our collection of open sets is pairwise disjoint.   What if our collection is disjoint in the sense that $$ \bigcap_{A \in \mathscr{A} } A = \emptyset, $$ but there exist sets $A, A^\prime \in \mathscr{A}$ such that $A \cap A^\prime \neq \emptyset$? Does the conclusion still hold?


How to find files containing two strings in different lines

A real example is: I have a Python file util.py, and I changed one of the function name from foo to bar. There might be other files using foo as function name and they are irrelevant.  I want to update all the Python files in the project from foo to bar. So I would like to do a search on files for imports such as:  import project.path.util   or   from project.path.util import foo   and any calls to foo such as one starting with:  foo(   The solution has to be whitespace tolerant. I can search each of them using grep but I am uncertain about the combined search. Any suggestions will be appreciated.


Should I replace the Canon 18-55mm f/3.5-5.6 kit lens with a 40mm f/2.8 or 50mm f/1.4?

So I'm about to buy my first DSLR (definitely a Canon, probably the 700D) and my original plan was to buy the one with the included 18-55mm f/3.5-5.6 kit lens.  At the same time I was thinking about picking up the 50mm f/1.8 on account of the fact that it's cheap and I love taking photos of people with a shallow depth of field.   A couple of friends who are big into photography both suggested that the kit lenses aren't that good and produce blurry, distorted and drab imagery. They also both suggested that I should use the money saved by just getting the body to offset the cost of a decent prime lens.  At this point their views differed:   One suggested that I should get the Canon EF 40mm f/2.8 STM. This works out at only £12 more expensive than the kit. They said it takes much better photos than the 50m f/1.8 for only a small amount more and it's very light. Another suggested that I go directly to the Canon EF 50mm f/1.4 as it's a lens that I'll never ever need to replace. This works out at £150 more expensive than the kit, although I can take (very small) comfort in the fact that I'm saving £80 by not buying the f/1.8 as a stepping stone to the f/1.4.   Both also suggested that once I'd had some lessons, learnt how to use the camera and absolutely must have a zoom lens, then I save up and look to buy something decent at that point in time, rather than use the kit lens.  Should I drop the kit lens and pick up a decent prime? Will I be missing out on some types of photography without the kit lens? Or should I start off with the kit and nifty-fifty and upgrade each component over time?


How do I turn off Windows 10 searching the store when I press start and type?

I just upgraded to Windows 10 1903 and now when I press Start and type Windows is showing store results    How do I turn that feature off? I don't want windows searching the store when I press the start key and type  Note: I tried the solutions listed . The Group Policies didn't make any noticeable changes (yes, I rebooted after enabling them). The notebook reference seems to be non-Pro as no such options show up.


Sequence of words in the non-question sentences

I have certain doubts, shall we say, about which of the following is correct:   I don't know where precisely you live; I don't know where precisely do you live.   For some reason I feel that the first one is correct, but I'm not sure about any actual rules governing the decision in this specific instance.  Would you please be so kind as to educate me what is the general guiding principle for such cases?  Sincerely Yours, Adrianna W. McCrory


What are all the font styles I can use in math mode?

As can be seen in above picture, there are lots of fonts or font styles that can be used in math mode.  What are all the fonts or font styles I can use in math mode, and which packages are required in order to use them?  Let's assume I'm using standard Computer Modern or Latin Modern (lmodern) fonts.  Edit: It'd be great to see examples of what the different styles look like, probably via images.    I'm not interested in a reproduction of the picture, which can be found at ; the picture is for illustration purposes only. Furthermore, this is supposed to become a one-catches-all question for questions like the beforementioned. If I actually were looking for these fonts, I wouldn't just lazily ask here but look e.g. at  , tables 3.14 and 6.4 first.)


Which function ($f$) is continuous nowhere but $|f(x)|$ is continuous everywhere?   I found this question , the question seems much interesting but for obvious reason it is closed there, I was wondering how to derive such a function?


Background colour in cycles render turning pink

I'm trying to set the background to blue yet whatever I do it still comes out as pink. Any ideas how to fix this?


Proof that exponential function's limit definition increases monotonically?

It is well known that we can define $e^x$ by the following limit  $$e^{x}=\lim_{n\to\infty}\left(1+{x\over n}\right)^n$$  I would like to show that the RHS sequence is always less than or equal to $e^x$ for all $-n\le x\le0$ and $n>1$, and what I had currently done is to study the property of this sequence (which is defined as $f(x)$)  $$f(x)=\left(1+{x\over n}\right)^n$$  I also find its first and second derivative $f'(x)=\left(1+{x\over n}\right)^{n-1}$ and $f''(x)={n-1\over n}\left(1+{x\over n}\right)^n$ and show that they are strictly positive for all $x\in[-n,0]$. As a result $f(x)$ is monotonically increasing and concave up. By plugging in the end points I found that $f(0)=1\le e^0$ and $f(-n)=0<e^{-n}$, I wonder if these conditions allow me conclude that $f(x)\le e^x$ for all $x\in[-n,0]$.


How does egg hatching distance relate to the hatched Pokémon?

I have different Pokémon eggs. One takes 10km to hatch, three take 5km, and the rest take 2km.  Which Pokémon can I get by hatching these eggs?


Added: 5 times down vote for now! Down voter is this religion or physics, please try to explain your decision.  I'm confused about this.  In physics we know for a , but I think that there is a contradiction in this term. The  are the phenomena that  contradicts the vacuum existence because, according to them, the vacuum isn't the empty space.  In vacuum the creation of particle-antiparticle pairs is allowed for small times and this is also proven in practice.  From the other side, the relativistic theory says about space-time that interactions like gravitation bend the vacuum (empty space). There seems to be a contradiction to me. If vacuum is an empty space then we can't bend it, because we can't bend something nonexistent. In other words: we can't bend 'nothing'.  Can empty space really exist in physics?  EDIT1: quote: Luboš Motl     "By definition, the space without   energy is the space whose total value   of energy is equal to 0."   But this space is nonexistent, so it is abstract and should exist only in our mind... Why is so? My second statement of this post says that in physics we cant bend nothing because such a bending is only thinking and not physics!  Another possibility is that space is unknown kind of energy, but this is contradiction in modern physics!  EDIT2:  Can any physics believe that nothing exists? By mathematical logic no! And mathematic is elementary tool in physics. Anything other than that is religion!  Nothing (empty space without energy) is only a logical state!  EDIT3: quote: Roy Simpson:     The General Relativity Vacuum is a   space-time model region without   matter.   and Luboš Motl says: "By definition, the space without energy is the space whose total value of energy is equal to 0."  Agree...   But this is only mathematical Euclidean space + time so this is only a mathematic and not physics! With other words: this is only a method of mathematical mapping. But, in real (not theoretic) physics we can't mapping empty things. Empty is only a logical state!  EDIT4:   Roy Simpsons argumentation seems to me acceptable.   quote: Roy Simpson:     Einstein struggled with this too, and   the problem has come to be known as   the "Hole argument" within GR. You   have to decide whether you are just   interested in GR's vacuum (empty   space) or the full physical vacuum   which includes quantum aspects as   well.   Thanks


Algebraic Proofs in Combinatorics $\binom{n + m}{2} = nm + \binom{n}{2} + \binom{m}{2}$

Prove the following identity using an Algebraic Proof.   $$\binom{n + m}{2} = nm + \binom{n}{2} + \binom{m}{2}$$  I have no idea where to begin on this problem or let alone finish it.


Concatenate many rows into comma-separated list based on unique id

I'm new to SQL (running SQL Server 2012), the query I'm running is returning these results.  IDNum   Email ----------------  1      a@a.com  1      b@b.com  1      c@c.com  2      d@d.com  2      e@e.com  3      f@f.com  3      g@g.com  3      h@h.com  4      i@i.com  5      j@j.com  5      k@k.com   I would like to get the following result set (a comma separated list unique to each id)  IDNum   Emails ---------------------------------  1      a@a.com,b@b.com,c@c.com  2      d@d.com,e@e.com  3      f@f.com,g@g.com,h@h.com  4      i@i.com  5      j@j.com,k@k.com   I've been trying to follow some of the answers from other questions but not having any luck. I'm sure it's some combination of my inexperience & all the other questions I'm finding with this are just results from a single table. My query is getting results from multiple tables if that makes a difference, would be similar to  SELECT DISTINCT      s.idnum, e.email FROM     student s JOIN      email e ON e.guid = s.guid WHERE      s.activeYear = 1 AND e.activeEmail = 1   Can anyone help? Thanks.  ******UPDATE******  I ended up using the following query after reading a few more articles here and on another website. Hope this helps someone in the future.  USE databaseName  SELECT s.idnum, STUFF(( SELECT ',' + e.email AS [text()]         FROM email e         WHERE         e.guid = s.guid AND e.activeEmail = 1         FOR XML PATH('')         ), 1, 1, '' )         AS emails     FROM student s  WHERE s.activeYear = 1


Jquery JavaScript click function does not work property

Hello guys I'm havin some troubles with a a little program, I hope you can help me. The issue is that when I make a click in a div it suppose to add and other in the other box div, and it words fine but the problem is when I'm trying to get the index of those divs added it iterate over the all divs each time.  <!DOCTYPE html>                <meta charset="UTF-8">         <title>Document</title>

uno

dos

tres

          This is the result when I click in them, it iterate each time    If I add directly in the console it words fine.  $('.dentro_contenedorb').click(function(){     console.log( $(this).index() ) }


Can't find circuit example for a solenoid valve 2W025-08

I recently bought  solenoid valve for an Arduino project where I need to flow liquid between 50 and 100 degrees Celsius.  I didn't find a circuit example or a technical sheet specific to this component. Based on a circuit I found for a different solenoid valve, I know I need a transistor and a rectifier diode in order to make it work but I'm not sure if I can use the very same components : A TIP120 Darlington Transistor and a 1N4001 Diode (  ).  Thanks for any help


...my phone thinks I need to know what amenities the hotel has. I've managed to shut off most of the other annoying alerts my phone wanted to throw out, but this one I haven't found in the menus. Where do I go to tell my phone I don't need to know about every hotel?


I want to calculate the limit $\displaystyle{\lim_{x\rightarrow 0}\frac{x^2\cos \left (\frac{1}{x}\right )}{\sin x}}$.   I have done the following:    It holds that $\lim_{x\rightarrow 0}\frac{x^2\cos \left (\frac{1}{x}\right )}{\sin x}=\frac{0}{0}$.   So, we can use L'Hospital's rule:  \begin{align*}\lim_{x\rightarrow 0}\frac{x^2\cos \left (\frac{1}{x}\right )}{\sin x}&=\lim_{x\rightarrow 0}\frac{x^2\cos \left (\frac{1}{x}\right )}{\sin x} \\ &=\lim_{x\rightarrow 0}\frac{\left (x^2\cos \left (\frac{1}{x}\right )\right )'}{\left (\sin x\right )'} =\lim_{x\rightarrow 0}\frac{2x\cdot \cos \left (\frac{1}{x}\right )+x^2\cdot \left (-\sin \left (\frac{1}{x}\right )\right )\cdot \left (\frac{1}{x}\right )'}{\cos x} \\ &=\lim_{x\rightarrow 0}\frac{2x\cdot \cos \left (\frac{1}{x}\right )-x^2\cdot \sin \left (\frac{1}{x}\right )\cdot \left (-\frac{1}{x^2}\right )}{\cos x} \\ & =\lim_{x\rightarrow 0}\frac{2x\cdot \cos \left (\frac{1}{x}\right )+\sin \left (\frac{1}{x}\right )}{\cos x}=\lim_{x\rightarrow 0}\left (2x\cdot \cos \left (\frac{1}{x}\right )+\sin \left (\frac{1}{x}\right )\right ) \\ & =\lim_{x\rightarrow 0}\left (2x\cdot \cos \left (\frac{1}{x}\right )\right )+\lim_{x\rightarrow 0}\left (\sin \left (\frac{1}{x}\right )\right )\end{align*}   We calculate the two limits separately   $\lim_{x\rightarrow 0}\left (2x\cdot \cos \left (\frac{1}{x}\right )\right )$ :    \begin{equation*}\left |\cos \left (\frac{1}{x}\right )\right |\leq 1 \Rightarrow -1\leq \cos \left (\frac{1}{x}\right )\leq 1  \Rightarrow -2x\leq 2x\cdot \cos \left (\frac{1}{x}\right )\leq  2x\end{equation*} we consider the limit $x\rightarrow 0$ and we get \begin{equation*}\lim_{x\rightarrow 0} \left (2x\cdot \cos \left (\frac{1}{x}\right ) \right )=0\end{equation*}    How can we calculate the limit $\lim_{x\rightarrow 0}\left (\sin \left (\frac{1}{x}\right )\right )$ ?


Is the product of closed subgroups in topological group closed?

Just out of curiosity: If $G$ is a topological group and $H, K$ are closed subgroups, is $H\cdot K$ a closed subgroup?  Thanks!


How to inspect an element's associated event handlers?

Possible Duplicates:              I am using Firebug to inspect HTML codes and CSS. I need to find what are the events and the handlers associated to an element.  Using the Inspect button, I can see all the CSS, but can't find the event handlers.


If else statement not being executed correctly

I am facing a very strange problem. I have written the below code.      if (verifiedStatus.equals("1")) {     imageView.setImageResource(R.drawable.ic_verified_user_black_24dp);     }      else if (verifiedStatus.equals("0")) {     imageView.setImageResource(R.drawable.ic_not_interested_black_24dp);     } else {}   As the code runs, if the value is 1, first the verified image comes but later it changes to the not interested image. I tried debugging and I saw that the code goes into an internal file/code and in the below lines, it changes the image to the other image.  for (;;) {     Message msg = queue.next(); // might block     if (msg == null) {         // No message indicates that the message queue is quitting.         return;     }   Can someone help me in resolving this issue?


How to redefine x,y,z orientation of a model?

I need to reset my model's x,y,z orientation.  The back of it needs to be aligned with the z axis so I can use the edge-fade method described here:    Right now the model's orientation seems to be at an odd angle.  Thank you for help!  EDIT: Problem solved.      This answers the question.  I am leaving my question here in case anyone else does not know to look for "normal orientation"!


Proof if $AB = BA$ is not verified, then $AB$ is not symmetric.

They ask me the following question:     Let $A$ and $B$ be two symmetric matrices of the same order, show that if   $AB = BA$ is not verified, then $AB$ is not symmetric.   I have tried the following but I do not know if it is correct:  if $AB \neq BA \Rightarrow (AB)^t = B^tA^t = BA \neq AB$


Is there a difference between  PRF and a hash function?  For example: Creation of a secret key is using PRF and creating a secret key is using hash function.


Are "there is" and "there are" with a compound subject, both correct?

Good pm, I would like to be further clarified if the following sentences are correct or incorrect, but I believe both are correct.     There is a cat and a dog.   There are a dog and a cat.    My point is, are these sentences correct? Yes or no? And why?


Prove for every two sets $A$ and $B$ that $A-B$, ${B-A}$ and $A \cap B$ are pairwise disjoint.     I'm really stuck on this one. I know pairwise disjoint means no two elements in $A$ and $B$ are the same. $A \cap B$ is the empty set, but how would I prove this?


External links to YouTube result in "video currently unavailable" in Chromium

BTW I don't consider this a duplicate as I am strictly speaking not troubleshooting codecs.  I have no problem playing you tube videos, if they are started from within the youtube website.  Ubuntu 12.04 LTS  Linux xxxx 3.8.0-35-generic #52~precise1-Ubuntu SMP Thu Jan 30 17:24:40 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux   Consistently, if I copy a link to a Youtube clip from any source, say Pidgin, and paste&go said link into Chromium, it results in "This video is currently unavailable". If I go to the same video after searching for it from Youtube, still in chromium, video runs just fine.  This would imply it has nothing to do with flash/html5/chromium-codecs-ffmpeg.   Videos work fine if I start them from the Youtube site.  Videos fail if I paste&go copied links.    In fact, if I pick a random video which is playing.  Copy the URL. Open a new tab and paste&go, it results in the "This video is currently unavailable" message.  So far, no explicit question in here, so I guess I should ask one. Where would I even begin troubleshooting this?    Asked to edit my "question" with what I've done to TS from thread   I have tried uninstalling and reinstalling chromium-codecs-ffmpeg, as well as the -extra variant.  claims I am using the default player and presents me the option to try html5.  This would imply I am not using html5. I have cleared cookies.  Once I realized chromium has no problems with playing any video if I start it from a link within the youtube site, I really stopped troubleshooting the actual player.   I can play any video, I just have to start it from within the youtube page. It is when I paste&go from a copied link that it always results in the error message.  I have not tried a proxy. I can do that later and update.  Proxying makes no difference.


Lightning Support for overloaded methods on server-side controller

Apex method being overloaded as:   Method(String param1, String param2) Method(String param1, String param2, String param3, String param4)   Whatever number of parameters we pass from helper.js to the server-side action call, it always calls the 2nd one(method with 4 params) listed above.   Any specific reason of overloading not supported?


Association of Python files in Windows not working

On my system (Windows Vista Home Premium 64bit) Python files are associated with Python interpreter:  C:\Users\Piotr>assoc .py .py=Python.File C:\Users\Piotr>ftype Python.File Python.File=c:\python\2.7\python.exe "%1" %*   Nevertheless when I run any Python script from command line a window titled Open With pops up asking me to Choose the program you want to use to open this file.


LaTeX to MathML conversion: tools, limitations, and approaches?

As far as I understand there are two ways to display LaTeX on the web:   The MathJax JavaScript library, which allows you to embed LaTeX directly within HTML tags, but such LaTeX is converted by MathJax to MathML, an XML format which browsers can understand, unlike LaTeX. The disadvantages of this approach is that MathJax support for LaTeX is limited (and perhaps it would be useful if someone could outline some of its most important limitations). Use a command-line tool to convert LaTeX to MathML (I've found , but wonder if there is a command line tool I can install on Linux or Windows or better on both). Apparently, this solution has fewer limitations. I would like to know what the best tools to use for this conversion are, and whether MathML has any limitations as far as the following go:    the MathML language's ability to encode everything that can be encoded with LaTeX syntax, and  any possible limitations due to incomplete browser support for MathML (judging from , Chrome support seems to be severaly limited compared to Firefox, but this also means that if a user of my site is not using Firefox, then they will not be able to see math properly, which is a real drawback!).    Furthermore, if there are any other approaches to displaying math on the web, without resorting to images and PDF files, then I would like to know about them, but I think the alternatives I mentioned are most likely the two and only most viable ones.


Set TextView of a Fragment with value generated in another Fragment (NPE)

I have an Activity QuestScreen, which at its creation holds the Fragment FragmentQuest. If i press at the Button, this triggers the next() Method of the Screen activity, leading to replace the FragmentQuest with FragmentAction.  The replacing works so far. The problem is, that after the replace i want to set a TextView in the FragmentAction, to avalue which is generated in the  QuestScreen Activity.  My first attempt was to set the TextView outside the onCreatView of  FragmentAction. This lead to a Nullpointer exception adressing the TextView.  So far I have looked at: , ,  and   The attempt seen below leads to an NullpointerException marked in the code.  In The QuestScreen Class   private void next(){      //The needed value for the TextView is stored in nextTransition     Transition nextTransition;     //Check if an entry is in the list     if(quest.getTransitionsAbleToFire().size() > 0){         nextTransition = quest.getTransitionsAbleToFire().get(0);          fragmentAction = (FragmentAction) fm.findFragmentByTag(TAG_FRAGMENT_ACTION);          // create the fragment and data the first time         if (fragmentAction == null) {             Log.d("QuestScreen onCreate" , "create fAction for first time");             // add the fragment             fragmentAction = (FragmentAction) Fragment.instantiate(this, FragmentAction.class.getName(), null);              fm.beginTransaction().add(fragmentAction, TAG_FRAGMENT_ACTION).commit();             FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();             fragmentTransaction.replace(R.id.flFragmentContainer, fragmentAction);             fragmentTransaction.commit();         }          //Triggers the corresponding activity in fragmentAction, to set the TextView to a value which is stored in nextTransition         fragmentAction.nextAction(nextTransition);         nextTransition.fire();      }     else{         CharSequence text = "Quest END";         int duration = Toast.LENGTH_SHORT;         Toast toast = Toast.makeText(getApplicationContext(), text, duration);         toast.show();     } }   In the FragmentAction Class  public class FragmentAction extends Fragment {  private TextView txtYourQuest;  @Override public void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setRetainInstance(true); }  @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {     // CREATE VIEWS HERE      View layout = inflater.inflate(R.layout.content_action_fragment, container, false);     txtYourQuest = (TextView) layout.findViewById(R.id.txtV_Your_Quest);     return layout; }  @Override public void onActivityCreated(Bundle savedInstanceState) {     super.onActivityCreated(savedInstanceState); }  public void nextAction(Transition prmTransition){      // --> Here in the enxt Line comes the NPE :  java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.app.Activity.findViewById(int)' on a null object reference      FrameLayout container = (FrameLayout) getActivity().findViewById(R.id.flFragmentContainer);     LayoutInflater.from(getActivity())             .inflate(R.layout.content_action_fragment, container, false);      txtYourQuest.setText("Your " + prmTransition.getAction().getPosition() + ". is to:\n "     + prmTransition.getAction().getActionName()); }


Exponential integral $ \int_0^\infty \frac{x^t}{\Gamma(t+1)}\text dt$

Now since the sum $$ \sum_{n=0}^\infty \frac{x^n}{n!},\quad x\in\Bbb R, $$ does have some relatively nice properties, is the same true for its analogues integral? If we take the gamma function to be a generalisation of the factorial with $\Gamma(n+1) = n!$, an obvious analogues integral formula would be $$ \int_0^\infty \frac{x^t}{\Gamma(t+1)}\text dt,\quad x\ge 0. $$ Does this integral have any similar, nice properties?


What should I do when a moderator deletes my post?

If a moderator deletes your post, what does it imply (assuming that no reason was given for the deletion)? Are you "in trouble"? For instance, if it seems to have been deleted inappropriately, is it fine to undelete it? And more generally, is it possible to get notification when your post is deleted? [Background: , which was deleted and is now locked.]


Standalone python app that uses qgis.core without installing qgis

I am building a standalone python application that has its own GUI, i would like to use qgis.core/pyqgis as a map display only. But from my searches on this topic, it seems that the full QGis software has to be installed on both developer and prospective users' machine to have this work. Is there not a way to embed Qgis map display without installing the full version of Qgis software?


Why do I keep getting 'failed to download' error whenever I try to download anything from the terminal?

W: Failed to fetch http://ppa.launchpad.net/ferramroberto/java/ubuntu/dists/raring/main/binary-amd64/Packages  404  Not Found W: Failed to fetch http://ppa.launchpad.net/ferramroberto/java/ubuntu/dists/raring/main/binary-i386/Packages  404  Not Found E: Some index files failed to download. They have been ignored, or old ones used instead.   I keep getting this when I download anything from the terminal.  How do I get around this?


Excel 2007 doesn't preserve asian characters when converting to csv

I am trying to save a spreadsheet as a CSV file. The file consists of korean characters, and the resulting csv has those characters literally converted to question marks (0x3F).  I am running on an English version of Windows but I (should) have the appropriate charsets installed.  The default encoding for non-unicode programs is English. I have no problems saving the files in other formats (xls or txt, for example).  This issue occurs for Japanese and Chinese characters as well.  The sample strings I used (in separate files) are  안녕하세요 你好 おはよう   None of files are exported correctly. Does Excel support asian characters when saving as CSV?  UPDATE  Decided to do some testing. Instead of trying to export from xls to csv, I instead created a csv manually that contains the following chinese characters: 你好. I am using Notepad++ to save the files. The purpose of this is to test whether excel can actually save CSV files with certain characters properly.  First, I encoded the file in UTF8 without BOM with .csv extension. I opened the file in Excel, and it rendered the characters as ASCII (therefore, incorrectly. Looks something like ä½ å¥½). However, when I saved the file, the characters were preserved when I opened it in notepad++ in UTF8.  Second, I created a new copy of the test file, but this time encoding it in UTF8 (with the BOM). I opened the file in Excel, and it read the file correctly (as 你好). I then re-saved the file, but this time it converted the characters to two question marks.  I found it interesting that while Excel correctly reads the file, it cannot re-save it correctly, but when it reads it as ASCII, it doesn't try to convert them but instead just outputs them as is. Seems like there is an issue when Excel tries to save unicode characters?  Workaround Solution  I saved the the document as Unicode Text which produces a tab-separated text file and it preserved the asian characters. There should be tools available to convert tab-separated files to comma-separated files.  Because the file is unicode encoded, all of the sample strings I've presented at the top (from three different charsets) appear properly.


What is the difference (if any) between "I should go," and "I ought to go"?


Do the penalties from Two Weapon Fighting and its improved version stack?

Does the additional off-hand attack penalty from Improved Two Weapon Fighting stack with that of the off-hand penalty from Two Weapon Fighting?  I ask because I am unsure if the -5 penalty for the additional attack granted by Improved Two Weapon Fighting stacks with the -4 offhand penalty for Two Weapon Fighting for a total of -9 or if the -5 replaces that penalty.


How can mesh have different material than particles?

I'd like to make the earth brown and the grass (particles) green. I've tried to follow tutorials and I don't find anything wrong about my settings. Here's the file:


GUI Card Layout- Action Listener not working

I only have the first button set up to work. It was working fine until I updated panel one to have additional panels (oneTwo,oneThree, etc.). I did this because I have to make the program look like this   but now when i click the first button it no longer switched to card two. I cant figure it out.  Here is my code  public class AddressBook implements ActionListener {     static CardLayout contentPaneLayout;     static JButton B1= new JButton("Create a New Address"),  B2= new JButton("Load Contacts"), B3= new JButton("Add New Contacts"),             B4= new JButton("View/Delete Contacts"), B5= new JButton("Backup Contacts"),  B6= new JButton("Exit"), B7 = new JButton ("Cancel");     static JTextField TF1 = new JTextField(13), TF2 = new JTextField (13);     static JLabel L1 = new JLabel ("Use The Buttons Below To Manage Contacts",JLabel.CENTER), L2 = new JLabel ("This is Card 2"), L3 = new JLabel("Username:",JLabel.CENTER),             L4 = new JLabel("Number of Contacts:",JLabel.CENTER);;     static Container contentPane;       public void actionPerformed(ActionEvent e) {         Object click = e.getSource();         if (click==B1) contentPaneLayout.show(contentPane,"Card 2");          if (click==B6) System.exit(0);         if (click==B7) contentPaneLayout.show(contentPane, "Card 1");         }      public static void main(String[] args) {         JFrame frm = new JFrame("Address Book");         contentPane = frm.getContentPane();         contentPane.setLayout(new CardLayout());         JPanel one = new JPanel (new GridLayout( 5,5 ));         JPanel two = new JPanel (new GridLayout(4,6));          JPanel oneTwo = new JPanel(new FlowLayout());         JPanel oneThree = new JPanel(new GridLayout(2,3,6,5));         JPanel oneFour = new JPanel(new GridLayout());         JPanel oneFive = new JPanel(new GridLayout());             one.add (L1);         oneTwo.add (L3);         oneTwo.add (TF1);         TF1.setEditable(false);         TF2.setEditable(false);         oneTwo.add(L4);         oneTwo.add(TF2);           one.add(oneFive);         one.add(oneTwo);         oneThree.add(B1); oneThree.add(B2);oneThree.add(B3);oneThree.add(B4);oneThree.add(B5);oneThree.add(B6);         one.add(oneFour);         one.add(oneThree);          two.add(L2);         two.add(B7);          contentPane.add("Card 1", one);         contentPane.add("Card 2", two) ;         //contentPaneLayout.show(contentPane, "Card 1");            ActionListener AL= new AddressBook();         B1.addActionListener(AL); B7.addActionListener(AL); B6.addActionListener(AL);         frm.pack();         frm.setSize(550,250);         frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);         frm.setVisible(true);     }  }


Is there any way to read deleted users' questions?

I was trying to access via Chrome's favourites links to an old question but when I try to do it, it says that the question is unavailable.  Seems that the user who asked it has deleted his/her account so the question is now also reachable with a Google search but not readable.  Is there any way to read a question even if the user who asked it deleted his/her account?  Thanks!  P.S.: Seems linke 10k+ rep users can read deleted questions. Does it concern also deleted users' questions? Should i be >10k rep?


How do i move apps and then information from the phone to the sd card

How do I move apps from my phone to the external memory. There is no option in settings to do this.


What if I received a check with two different amounts written on it (words vs. number)?

I received a check personally written to me from a family member.  The family member that wrote & sent me the check wrote where you write out the amount of what the check is suppose to be for, in words, "Fifty Dollars-------00/00".  Then, in the box above where you write the amount with numbers, they wrote "25.00".  They signed the check and mailed it to me to cash.  What should I do?


After I compile my code, I see this as the output:  [I@7852e922  I'm assuming I need to use Array.toString after some searching but when I  I seem to have other errors so I'm assuming I'm not putting it in the right place.  Here is my code:  public class TwoSum      {         static int[] arraynums = new int[]{2, 7, 11, 15};         static int target = 9;          public static void main(String args[])         {             //TwoSum name = new TwoSum();             //name.twoSums(arraynums, target);             System.out.println(twoSums(arraynums, target));         }             public static int[] twoSums(int[] nums, int target)              {                 int sum = 0;                  for (int i = 0; i < nums.length; i++)                 {                     for (int j = 0; j < nums.length; j++)                     {                            sum = nums[i] + nums[j];                         if (sum == target)                         {                             //System.out.println(i + " " + j);                             return new int[] {i,j};                         }                      }                 }                 return new int[] {};             }     }


Why generics cannot be used in Exception classes in Java?

An attempt to use generics with any class that extends Throwable produces an error saying "Generic class may not extend 'java.lang.Throwable'".    Sample code:  public class GenericException<T> extends Exception { }  // Compilation Error   I am not able to understand why generics cannot be used inside classes that extend Throwable.  Could someone explain?


Using Mac to create bootable usb stick for Windows

What directions should i be following to use my friends mac to create a bootable usb stick for an old hp pavilion dv4?  The hp pavilion doesn't seem to have any operating system, it tries to boot windows but it's 'missing' something and tells me I need to install Windows, but I'd rather install ubuntu. Please help me!


Power on a Linux machine at specific time

I have a Linux laptop and I want to set it up as an alarm clock (used to have it on my Mac years ago).  The problem is if I shutdown my laptop the night before, the alarm will not work.  Is there a way to set up time schedules in Linux when the machine should power on? Or do I have to do this in BIOS/UEFI...somehow?  It should also wake up from sleep or hibernation.  EDIT: The duplicate question talks about waking up the machine from sleep or hibernation. I want to turn it on from a complete shutdown. I know this can be done on Macs.


How to install GNOME 3.10 in Ubuntu 13.10?

I am using Ubuntu 13.10. Is it possible to install GNOME 3.10 in it?


PHP $_SESSION variable causing errors with mySQL

I am trying to select data from mySQL database, I execute the following code:     <?php $_SESSION["dog_park"] = $_GET['keyword'] ?>

<?php echo $_SESSION["dog_park"]; ?>

             Park Name	             Street	             Suburb	             Dog Park Area (m2)

     <?php          $result = $conn->prepare("SELECT * FROM dog_parks.items where suburb = '$_SESSION[dog_park]'");         $result->execute();         for($i=0; $row = $result->fetch(); $i++){     ?>
             <?php echo $row['Park_Name']; ?>	             <?php echo $row['Street']; ?>	             <?php echo $row['Suburb']; ?>	             <?php echo $row['Dog_Park_Area_(m2)']; ?>
         <?php } ?>

   When that script executes it displays the following error:   It has something to do with the session variable, if i enter a static value for    the mySQL query it will display table data correctly, but fail when the $_SESSION variable is present.


What's the best strategy for spell checking LaTeX documents?


soul package \hl with \cite gives error: "@citex has an extra }"

The following MWE gives me an error. This should work, shouldn't it?  \documentclass{article} \usepackage{color,soul} \begin{document} \hl{A statement \cite{hong_groups_2004}} \end{document}   Here's the error:  ! Argument of \@citex has an extra }. <inserted text>                  \par  l.4 \hl{A statement \cite{hong_groups_2004}}


Windows 7 not finding any updates after clean install

I just did a clean install of windows 7 professional 64-bit on my skylake build and I was able to install windows 7 fine, I even installed the usb drivers, chipset drivers and the rest of the drivers needed. I installed it from a dvd (it had service pack 1 on it) and had a brand new product key (never used on another pc), even when I go to system properties it says that "windows is activated," but when I plugged my ethernet in and connected to the internet, windows update isn't finding any updates. I open windows update and it has been searching for updates the last 30 minutes now and found nothing, Does anyone knoe what go be wrong because I know the dvd would not have the most recent updates? Yes, my internet works fine I am able to go on google chrome and surf the web.


Show that if $\vert G\vert = pq$, then either $G$ is abelian or $Z(G) = \{ e\}$.

The center of a group $G$ is defined as $Z(G):=\{ z\in G : gz = zg, \; \forall g \in G\}$.  The goal is to show that if $\vert G\vert = pq$, where $p$ and $q$ are not necessarily distinct primes then either $G$ is abelian or $Z(G) = \{ e\}$.  I want to suppose that $Z(G) \neq \{ e\}$ and then use the fact that $G/Z(G)$ is cyclic to imply that $G$ is abelian, which is something I have already proven. But how do I show that $G/Z(G)$ is cyclic when I am not certain what exactly $Z(G)$ looks like. I only know that it has at least one non-identity element in it, which will be of order $p$ WLOG, (the case where it is of order $pq$ is trivial).  Any help is appreciated. Thank you.


Shouldn't wiki review rejects of plagarism have a source?

I submitted a  and one reviewer said the material was plagiarized.  I don't mind saying my contributions are minor, etc.  However, this is a particularly nasty form of rejection.  I have written this text from scratch. It is possible that my memory sub-consciously found something I read in the past.  Perhaps this was an incident of clicking on the wrong reason radio button or maybe the intent was references are needed?  I actually search around the web for references, but I didn't find anything.  Wouldn't some additional text showing the source of plagiary be very helpful?    The only source I may have quoted was  were they noted a difference between backtick and $() to allow nesting.  However, I thought the text was significantly different and it originated on stack overflow?         Plagiarism is not a crime per se but in academia and industry it is a serious moral offence, and cases of plagiarism can constitute copyright infringement.    Certainly when ever I am writing a tag wiki I look at all the question tagged on stack overflow.  Is this considered an infringement?  I thought we were sort of a collective and the tag wiki shouldn't have to attribute the question the tag is describing.  Some sort of additional text on what the plagiary was would be most helpful.  Edit: For reference, here is the reject reason list [as of Dec 2013].    The copied content is the first reason in the list; which causes the plagiary reason text.  This is unknown to some lower reputation users of stack overflow.


Confidence Score for a Single Proportion

I was asked to calculate a confidence score for a single proportion representing a conversion rate. I saw a lot of documents that calculate confidence intervals for proportions based on the binomial distribution; however I did not see any material for a single conversion (or proportion). If $X \sim Bin(n,p)$, with large sample size normal approx to binomial is valid, then  $$ \hat{p} \leadsto \mathcal{N}\bigg( p, \sqrt{\frac{p(1-p)}{n}} \bigg) $$  Using this approximation, I saw statistical significance involving a second ratio (through $z$-scores) can be calculated, etc. However, can any error metric be calculated for a single proportion? Ideally this metric would be a number between 0% and 100%.


Aluffi II.3.4 asks the reader to find groups $G$ and $H$ such that $G\times H\cong G$ but $H$ is not trivial. I believe I have found a solution, but would like someone to check. Also, is there a more elementary example? I tried mucking around with $S^1\times (\Bbb Z/2\Bbb Z)$, which feels like it should be isomorphic to $S^1$ (the unit circle under complex multiplication), but I kept getting confused.  My solution  Let $H$ be a non-trivial group and let $G=H^\omega$. Then $\phi\colon H\times G\to G$ defined by $$\phi(h,g)_n=\begin{cases} h &n=0\\ g_{n-1} &n\ne 0 \end{cases}$$ looks like a group isomorphism to me. It's obviously a bijective function, and \begin{align*} \phi((h_1,g_1)(h_2,g_2))_n &=\phi(h_1h_2,g_1g_2)_n \\ &=\begin{cases} h_1h_2&n=0\\ (g_1g_2)_{n-1}&n\ne 0 \end{cases}\\ &=\phi(h_1,g_1)_n\phi(h_2,g_2)_n \\ &=(\phi(h_1,g_1)\phi(h_2,g_2))_n. \end{align*}


How does interspecies reproduction work in the Lord of the Rings universe?

So, I know that there is a race in Lord of the Rings of Peredhil  (half elf). Also, in the Hobbit (film trilogy, not book), there is a romance between a dwarf and an elf.  My question is, how do man/elf or dwarf/elf offspring work? Can they not be born? Are they born infertile because they are from parents of two different species? Are elves, dwarves, and men only different "races" of one single primordial species, and can thus reproduce any number of ways? To my knowledge, this isn't addressed in the books or films.


"ERROR while getting interface flags: no such device"

The command  airmon-ng start wlan0   gives as output  Found 5 processes that could cause trouble.   If airodump-ng, aireplay-ng or airtun-ng stops working after   a short period of time you may want to kill (some of) them! PID    Name 3258   wpa_supplicant 4175   NetworkManager 4180   dhclient 4190   avahi-daemon 4191   avahi-daemon  Process with PID 4180 (dhclient) is running on interface wlan0  Interface       Chipset       Driver    wlan0           Unknown       wl - (phy0]mon0: ERROR while getting interface flags: Onjuist apparaat                                  (monitor mode emabled on mon0)   and then I type  ifconfig mon0 down   and I get this error:  ERROR while getting interface flags: no such device   The error will probably start at airmon-ng start wlan0.


I want to know the file permission code  I have run the command and get this code, How can i know which file has which permission  ls -l  -rw-r--r-- 1 www-data www-data   4253 Mar 16 10:17 1426481278-xAx-flame.jpg --wxrw--wt 1 www-data www-data 174613 Mar 16 10:17 1426481278-xAx-flame.mp4   Please tell me  -rw-r--r--  --wxrw--wt


I am not sure how it happened but all my faces are now semi-transparent in Edit Mode.    I have tried multiple settings to get solid faces back. I am not in wire frame mode and I made sure that "Limit selection to visible" is disabled as see in the picture. I have no idea why I can't get my solid faces back.   Any help is greatly appreciated,  BloodHound27


My Nexus 4 won't upgrade - I keep getting an error

I have an unrooted Nexus 4 and running Android 5.0. When the 5.0.1 OTA update came out I could download it and start installing it and then get screen that said error with the android robot on it's back but with no helpful information. I just tried again with 5.1 and I got the same problem. I factory reset my phone and it still doesn't work!  Please can someone advise on what to do?   Thanks in advance.


This problem was inspired by .  Given $12$ numbered ($1$ to $12$) pigeonholes and $12$ numbered balls (also from $1$ to $12$); what is the probability that a random permutation would leave no balls in its corresponding hole?  Let $a_n$ be the set of permutations of numbers $1$ through $n$ such that for all $1\leq i \leq n$, $perm[i] \neq i$. Clearly $a_1 = 0$ and $a_2 = 1$. I noticed that the following recurrence relation: $$ a_n = (n - 1) (a_{n-1} + a_{n-2}) $$  was successful at predicting $a_n$ for $n = 3, \ldots, 12$. I wish to understand the following:   The justification for the recurrence relationship. My idea was the following: For the first hole, there is a total of $(n-1)$ possibilities. After one such number has been picked, we go to the index $i$ corresponding to this number. In case the $i$th hole points back to the first hole, this means the total number of possibilities is given by $a_{n-2}$. If it does not, the total number of possibilities will be given by $a_{n-1}$. This isn't quite satisfactory as there is also the possibility that $i$ points to hole $j$ and $j$ points back to the first hole. I noticed that the probability $a_n/n!$ tends to $1/e \approx 0.3678794\ldots$ when n tends to infinity. What is the reason for this? Is there a way to solve this recurrence relationship such that I can obtain $a_n$ without calculating every $a_i,i<n$?


I DON'T want Windows 10 -- what should I do to dismiss reminder?

Starting from today morning (at least in Poland) all my computers with Windws 7 started to showing a reminder, that I can reserver free future upgrade to Windows 10. Here is a Polish example:    On my home computer I registered, but on my office computer I was instructed to not reserve slot for future upgrade. However, no matter, what I do, reminder's icon in tray area (next to system clock) is always there. Closing or selecting anything brings no effect.  How to get rid of this reminder, so it would be closed permanently and never show up again?


Ways to update Ubuntu (debian-based distros) offline

What is the easiest way to update/upgrade an offline Ubuntu machine with the help of a Windows machine that has internet access?  This question also applies to installing new packages offline and not only updates/upgrades.  The Linux system shall remain completely cut off from the Windows machine, meaning there should be no ethernet connection or the likes between the two computers.  Update:  Please have patience, since I haven't updated this since two weeks. There are some complications getting apt-offline to work properly on Lubuntu and all other methods seem to be too old and deprecated:  AptOff - last update 2006 AptMedium - last update 2007 Keryx - last update 2011, looks like this project was discontinued  I hope I will be able to somehow update the offline machine, finally.  While I was still not able to update/upgrade the offline system due to authentication errors, I accepted an answer, because it's taking too long.


Why do positive and negative variants of the same question elicit the same answer?

In common American English usage, these two questions elicit the same response:   Do you have a ticket? Don't you have a ticket?   These are the usual answers (I was going to say "possible answers" but I can think of a whole host of situations where one could get other answers, e.g. wake up someone in the middle of the night and ask it, the answer might easily be "I don't know" or "maybe" or "hey, just let me sleep!"... but that's neither here nor there... :-)   Positive: "Yes" or "Yes, I do". Negative "No" or "No, I do not".   But consider this: the questions are logically equivalent to:   You have a ticket, right? You do not have a ticket, right?   Here I am not so sure that a "Yes, that's right" response means the same thing to each question. (One could still, however, use "Yes, I do" as @F'x answer in  illustrates, to remain valid and unambiguous.)  (As a side note, it is interesting to compare the same question in Chinese, where one literally asks "Do you have/not have a ticket?" and the common answers are:   "[I] have" "[I] not have"   ...which also removes the ambiguity... while at the same time straying from my original question:-)  So why can I rewrite the questions so that they are essentially equivalent yet expect different answers?


Find the Fourier transform of the absolute value of a function, given its Fourier transform

It is possible to find the following Fourier transform? $ \widehat{\vert f\vert}(\xi)$, provided $ f $ has Fourier transform. I have not found any information about this statement.


problem when installing vlc on ubuntu 15.04 its taken more than 10 hrs but not successfully installed and give the msg

The following information may help to resolve the situation:  The following packages have unmet dependencies:  vlc : Depends: vlc-nox (= 2.2.1-2~ppa1) but it is not going to be installed        Depends: libavcodec56 (>= 6:11~beta1) but it is not installable or                 libavcodec-extra-56 (>= 6:11.2) but it is not installable        Depends: libavutil54 (>= 6:11~beta1) but it is not installable        Depends: libqt5x11extras5 (>= 5.1.0) but it is not installable        Depends: libsdl-image1.2 (>= 1.2.10) but it is not installable        Depends: libva-drm1 (>= 1.1.0) but it is not installable        Depends: libva-x11-1 (>= 1.0.3) but it is not installable        Depends: libva1 (>= 1.2.0) but it is not installable        Depends: libvlccore8 (>= 2.2.0~pre1) but it is not going to be installed        Recommends: vlc-plugin-notify (= 2.2.1-2~ppa1) but it is not going to be installed        Recommends: vlc-plugin-samba (= 2.2.1-2~ppa1) but it is not going to be installed E: Unable to correct problems, you have held broken packages.


Do I need to license fonts included with my OS?

I've noticed that most custom fonts include a license.txt file that requests some amount of money for a commercial license.  I am interested in whether it is also necessary to license OS (Mac/Windows) included fonts for commercial use.  As a side question, is font theft an issue in the industry?


How to install a .deb pacage without internet AND Synaptic?

I am having an issue with installing a .deb file. I have tried already: sudo dpkg -i my_file.deb (Yes I've made it executable with chmod: +x my_file.deb) and the package manager. Please Help.


Are the coefficients of $n^{th}$ order monic polynomial with distinct roots in $\mathbb C$ dense in $\mathbb R^n$

Suppose for a $n^{th}$ order monic polynomial $p(t) = t^n + \alpha_{n-1}t^{n-1} + \dots + \alpha_0$, we identify the coefficients in $\mathbb R^n$, i.e., $\alpha = (\alpha_{n-1} ,\dots, \alpha_0) \in \mathbb R^n$. Let  $$\mathcal F = \{(b_{n-1}, \dots, b_0): p(t)=t^{n} + b_{n-1} t^{n-1} + \dots + b_0 \text{ has $n$ distinct roots in $\mathbb C$}\}.$$ I am wondering whether $\mathcal F$ is dense in $\mathbb R^n$.


What do you call a person who is given money to cash your check, usually using force, when the indebted people refuse to give your money back?

There are times when you have received a check from somebody, but there is no money (or not enough money) in their account to cash it. Then you have to resort to asking someone (criminal or something) to tackle the problem and hopefully get the money (or part of it) one way or another.  Is there a word to refer to such a person (criminal)?


I've got a single page on my blog for the pdf publications embedded from sites like Issuu.com   Each of these publications is embedded using the iFrame.  These are slowly piling up and I will very soon end up with 20 iFrames embedded  into one single page.  I am quite worried about SEO in this case. Does putting several iFrames into one single page affect SEO ??


package A;    //it has a class to connect to a database    public class refer {       static connect obj = new connect();   }             I want to use the above object in another package     import A.refer;    class X {       public int calculate() {           int result = refer.obj.methodname();           return result;       }   }   Error i am getting- The field refer.obj is not visible.


If R is a Noetherian ring, is it true that there exists an integer N such that every ideal of R is generated by at most N elements?

I think, as R is an ideal of itself, and R is Noetherian thus R is finite generated, assume it is generated by N elements, then every ideal is generated by at most N elements. But my conclusion is wrong, could you tell me where I made mistakes? Thank you!


How do I extract the text content of an article site with Python 3?

I've tried the following:  import urllib  link = 'https://automatetheboringstuff.com/chapter7/' f = urllib.request.urlopen(link) myfile = f.read() print(myfile)   But that just seems to return the page's source rather than the text content.


What's the difference between "should" and "could" (in the present tense)?

I am not referring to could as a past tense of can  What is the difference between the following sentences?     You should do it.   You could do it.


Only one truthy bool value for one foreign key in postgre

Lets assume we have 2 database tables (entites). The first is named A and the second one is named B. There are 1:N (where N > 0) relationship (so every record in table A is in relation with 1+ records in B table).  Table A (for simplicity assume there is just id in this table, other table columns are not relevant for this question)  Table B    id (bigint) <- primary key defaultForA (boolean, default = false) a_id (bigint) <- foreign key for table A record   Is it possible to set table contraint that will check there is only one truthy value in defaultForA column for every present a_id value? For example we have 2 records in table A (with IDS 0,1)  And 4 records in table B  id, defaultForA,a_id  0,true,0  1,false,0  2,true,1  3,false,1  This is completely fine state. For each A record I have one "default" value from B table The constraint should not allow me to add following record to table B  4,true,0  Because there is alredy record linked to record 0 in table A that have defaultForA property set to true


Can't find smoke and color mapping options for Fluid Simulation Blender 2.9

I am trying to make an explosion with Blender Mantaflow, but I do not see the following in the Properties view in the Physics Properties:  Color Mapping Smoke   I am using Blender 2.91. Can you help me solve the problem?


I would like the Stack Exchange sites to provide a way for members to respectfully agree or disagree with the closing of a question, particularly if it is marked as "off topic" or "duplicate". Over the years I have obtained a great deal of very useful information from questions that are closed, and in most of those cases I disagree with the decision to close it. I believe this will benefit the Stack Exchange communities in two important ways:   The body of subject matter that is deemed "on topic" is controlled by a very small group of elite members. Considering (a) the number of upvotes on closed questions, and (b) the number of closed questions that appear as top-ranking results in Google searches, it seems evident that the communities using these sites do not entirely share the views of the elite. The upvote/downvote on question closure would allow the community to respectfully participate in defining the bounds of subject matter for each Stack Exchange site. The definition of "duplicate" is much more subjective than its boolean nature suggests. From one person's perspective, two similar questions may seem incontrovertibly identical, because that person finds no additional value in the subtle differences between them. But a second person may find those same two questions to be distinct in some important way, for example if one of the questions emphasizes an aspect of the issue that the other does not (and contains helpful points on that aspect). These subtle distinctions may be difficult for a moderator to see, especially since the moderator is not reading the question with the goal of solving a problem.    If this feature were implemented, it might be prudent to restrict the new upvote/downvote on question closure to members with a certain reputation level, since newer members may not have enough experience in the community to understand its values and goals. The moderators can still have the final say about closing questions, but should be notified when any of their closures has received a very large number of contradictory downvotes. They can still say "well people just don't get it," but at least they should know that the community strongly favors a different perspective.


Where to ask logic questions: not math logic but common real world problems

I wanted to know answers to questions something like:      "A man wants to take his wolf and two sheep across the river using a boat in such a way that he can take only one animal while travelling on the boat from one side to another side. Wolf eats sheep in the absence of the man. What does man do without wolf causing any harm?"   Where can I ask these kind of questions please?


I am getting a NullPointerException when i run this code

Hi guys i have a NullPointerException when i run this code ,and its pointing on the model = (DefaultTableModel) DbUtils.resultSetToTableModel(rs) , and i have imported the net.proteanit.sql.DbUtils , any ideas ?  public void setTableValues(){          try {              cn.start();              String sql = "select id,first_name as Firstname,last_name as Lastname,email,phone,description as AllergyInfo from clients where isDeleted=0";              rs = cn.executeSelect(sql);              model = (DefaultTableModel) DbUtils.resultSetToTableModel(rs);              jTable1.setModel(model);              rowSorter = new TableRowSorter<>(jTable1.getModel());              jTable1.setRowSorter(rowSorter);              cn.stop();          } catch (SQLException ex) {              Logger.getLogger(Clients.class.getName()).log(Level.SEVERE, null, ex);          }     }


Ubuntu 16.04 Installation Issue Boots Into Black Screen or Freezes - Nouveau/Nvidia Driver issue 1080ti

My research into the problem has found relevant information which I posted at the bottom.  Problem - I am trying to format my current partition of Ubuntu Gnome 17.04 and and install Ubuntu Gnome 16.04 onto my desktop and I cannot get the installation from the usb boot drive to work.   Expected solution - At first I was confused because I installed ubuntu before on this computer and didnt have any issues and thought it was a uefi issue or something. I have recently upgraded my graphics card and I believe that is the issue based on the below links. I expected the problem to get fixed by turning on nomodeset but it did not solve the issue.  I have been dealing with this problem for over a week and I appreciate any and all help.  I have not tried to download Ubuntu server like one of the solutions suggested.    What I have tried:  I know the usb drive works because I can do it on my laptop. From the    boot up menu I have a few options to boot from my usb: uefi usb, just    the usb, or uefi shell.   When I choose the uefi drive option grub    comes up and gives me 3 options (install, install oem, check disk)    and when i choose install, it goes to a black screen where there is a    cursor that blinks 6 or so times and then freezes.   If I choose the    non uefi usb option, i have a few options. A screen comes on that    shows something like a battery and a person at the bottom, if I let it run I get    many lines printed out that follow the following format (only the    first number changes) in the print out:      [6.4XXXXX(monotonically increasing numbers)] nouveau 0000:01:00.0 fifo: SCHED_ERROR 08 []    if    i hit the down arrow a Ubuntu start up screen comes up. Ive tried to    boot from that menu after hitting F6 and turning on nomodeset,    acpi=off, and nolapic but I get the same issue as the uefi boot (blank screen).   Thanks for any and all help!  Hardware:   Mobo - MSI Z97 PC Mate CPU - Xeon e3 1231 v3 GPU - EVGA 1080ti FE Monitor - 29" UHD LG    Software:   I dual boot ubuntu gnome 17.04 and Windows 10.   Similar posts:            Bug report -