From the datasheet the open loop phase shift is given as 90 degrees for a range of frequency. But why doesn't a a normal open loop inverting amplifier does not show this characteristics of the phase shift of 90 degree.Instead it just inverts the output(Or say 180 degree phase shift).    What happened to the phase shift given by a Op amp?


amsmath: error using subequation environment "Missing \endgroup inserted \end{align}"

Here's my minimal problem-causing example:  \documentclass{standalone} \usepackage{fixltx2e} \usepackage{amsmath}  \begin{document}      \begin{subequations}         \begin{align}             a &= b + c\\             a' &= b' + c'\\         \end{align}     \end{subequations}  \end{document}   Here's the log output:  line 14: Missing \endgroup inserted \end{align} line 14: Missing \endgroup inserted \end{align} line 14: Missing } inserted \end{align} line 14: \begin{document} ended by \end{align}. \end{align} line 14: Missing $ inserted \end{align} line 14: Display math should end with $$ \end{align} line 14: Extra \endgroup \end{align} line 15: \begin{document} ended by \end{subequations}. \end{subequations} line 15: Extra \endgroup \end{subequations} line 17: Too many }'s \end{document}   What is the issue?


How long does it take before journals reject a submission?

If an academic submits a paper to a journal, it is helpful to know as fast as possible whether that journal will accept it, so that he/she can submit it to an alternative journal as fast as possible.  How long will it generally take before you know that the first-choice journal rejects your paper? Does it ever happen that the journal simply doesn't respond? (as some employers do when you send an application for a position).  I know that it is considered unethical to submit to multiple journals at once, but that does mean that the journal has a responsibility to let you know as fast as possible whether the paper is accepted or not.  (ps. I haven't published anything before)


Why does a $1/2$ appear in this simple capacitor equation?

The maximum energy stored by a capacitor is when it’s (theoretically) fully charged, or just before it reaches dielectric breakdown, if you will. It seems, then, that the maximum energy ($E$) $=QV$, where $Q$ is the maximum charge attained and $V$ is the maximum ‘voltage’. However, the correct equation for the maximum energy is $E=\frac{1}{2}QV$. Why? I’m looking for a simple, intuitive explanation because my reasoning that $E=QV$ seems sound to me. I know about , but I’m looking for a reason to disprove my specific argument that $E=QV$ and not the “Oh, it comes from integration.” response.


Feats for an Advanced, Mindless Plant Creature

So for story purposes I'm advancing a CR 2 Plant Creature called a  to a CR 20.  Now when I read over the rules of advancement, they talked about giving the advanced creature feats. Now as a mindless creature I'm not sure what feats would be beneficial/are legal for it to acquire.


How to perform a boolean check in Processing on a value from serial string?

I have a simple push button connected to pin 2 on my Arduino. I can read this value and print it to the serial monitor without any trouble:  int pushButton = 2;  void setup() {   Serial.begin(9600);   pinMode(pushButton, INPUT); }  void loop() {   int buttonState = digitalRead(pushButton);   Serial.println(buttonState);   delay(1); // delay in between reads for stability }   This prints a value of 0 when the button is not pressed, and 1 if it is.  In Processing, I want to check if the value is zero or one, and perform some conditional logic. But I can't get the equality right:  Serial myPort; String resultString;  void setup(){   size(640,480);   printArray(Serial.list());   String portName = Serial.list()[2];   myPort = new Serial(this,portName,9600);   myPort.bufferUntil(10); }  void draw() {   // }  void serialEvent(Serial myPort){   String inputString = myPort.readStringUntil(10); //until newline or ("\n");   inputString = trim(inputString);   println(inputString);   if (inputString == "1"){ //this doesn't work, even though println will render ("1") plus the newline if button is pushed.     println("on");   } else {     println("off");   } }   How do I set up this conditional to do one thing if the button is pushed, and another if it is not?  I've tried converting the string to an int using   inputInt = Integer.parseInt(inputString);   and then performing the check, but it didn't work.


After catching the first pokemon you are left to catch pokemon as you wish with no further explanation on how best to catch these pokemon.  After throwing around 10 balls and having them hit away/dodged and just rolling pathetically on the ground, I realised there must be a technique I missed.  How should you approach a wild pokemon encounter so as to maximise catching probability?


I'm having a rough time getting blender (2.79) to play nice with user preferences.  Per the documentation @ :     For locally extracted Blender distributions, the user configuration   and runtime data are kept in the same sub-directory, allowing multiple   Blender versions to run without conflict, ignoring the USER and SYSTEM   files.   However, with a locally extracted version of blender (I have both an installed and an extracted version of blender, both 2.79), it refuses to use a local preferences file, rather it is using the "global" or system-based user preferences file.  This was a big hit to my DCC station's setup, as I wasn't expecting this behavior.  I made a TON of changes in the locally extracted version, not expecting those changes to affect the installed version.  Now we've lost a highly customized base user-preferences file.  My bad...  Alas, I need to figure out how to force blender to use a local preferences file, and not modify the system based preferences.  I don't feel like hitting my self in the face with a brick.  I'm not sure if I should submit a bug report about this, as well?  I assume I've made a mistake, yet the official documentation literally states the intended behavior is for locally extracted versions to use local configurations and runtime data, to AVOID conflicts like this.  Any guidance here would be greatly appreciated!


Trouble with "trivial" example of a semi-simple Lie algebra

If the radical of a Lie algebra is zero, we call it semi-simple. In the lecture notes that I'm following its stated that for any arbitrary Lie algebra (over a field with characteristic zero and finite dimensional) $\mathfrak{g}$ we have, $\mathfrak{h}:=\mathfrak{g}/\mathrm{rad}(\mathfrak{g})$ semi-simple. I have trouble seeing why.   I need to show that $\mathrm{rad}(\mathfrak{h})=0$. I think we can use the fact that if $\mathfrak{I}$ is a solvable ideal of $\mathfrak{g}$ such that $\mathfrak{g}/\mathfrak{I}$ is solvable, then $\mathfrak{g}$ is solvable, but I'm not really sure how...


Why are two such similar movies being made at the same time?

Everybody perhaps knows of Jon Favreau's movie  which is going to be released in 2016. But quite recently I learned (and to my utter surprise) that another Jungle book movie is coming in 2017 and it's called .   Now, this movie has big names too with Christian Bale as Baghera, Benedict Cumberbatch as Sher Khan, Cate Blanchett as Kaa and a young Indian boy in the live action role as Mowgli.   How often does this happen, with two big productions with big cast making a movie on the same subject? I want to ask why this is happening and if there are any really significant differences between the two (apart from the cast, of course).


how i can save multiple lines inside a string in java

user have to write an email in multiple lines and stop the input when ".." (two dots) are entered by the user. then the email should be saved to the variable but the variable saves the last input which are the two dots. this is my code  any changes?  BufferedReader inl = new BufferedReader(new InputStreamReader(System.in)); String email_data;  System.out.println("Data: ");  do{     email_data = inl.readLine(); } while(email_data != "..");


I have B1/B2 Visa. Can I travel for Business trip to US with this Visa?

I have been given B1/B2 Visa, but first time when I had applied, it  was for vacation & holiday. Now I need to go to US for business meetings. Is this Visa good enough or do I have to apply for a B1 Visa again?  Note: I originally applied for vacation purposes, but in my visa it is stamped "R b1/b2"


Proving a sequence defined by a recurrence relation converges

How can I prove that this iterative sequence converges to $2$? Can I use the convergence definition?  $$a_{n+1} = \frac{a_n}{2} + \frac{2}{a_n},\qquad  a_0 = 4  $$  Thanks for the help.


I want to update my Ubuntu version. but how I can update it?


I read from  that the geometric standard deviation is  $$\sigma_g = \text{exp}\left( \sqrt{\frac{\sum_{i=1}^n\left(\frac{A_i}{\mu_g}\right)^2}{n}}\right)\,, $$  where $\mu_g$ is the geometric mean, $A_i$ is the observation $i$, and $n$ is the sample size.  How can I calculate a confidence interval for a geometric mean?  Is the standard error for the geometric mean $se_g = \frac{\sigma_g}{\sqrt{n}}$? Assuming the distribution of $A$ is normal, is my 95% confidence interval for the geometric mean $\mu_g - 1.96 \cdot se_g < \mu_g < \mu_g + 1.96 \cdot se_g$


Looking for a word that means to give for free, but is distinct from "donate"

I'm writing about how companies in a particular industry are responding to the Covid-19 situation. I'm categorising their responses and labelling each category with a single word.  Two categories are similar yet different enough to remain distinct. I'm struggling to find single-word labels for them that are sufficiently differentiated. Currently I have:  "Giving" - companies are giving some of their products and services to regular and vulnerable customers for free to help them through the crisis (and of course to generate goodwill, customer loyalty, CSR points, etc.). For example, giving an extra 50% when a customer renews, making premium services freely available for a limited period, etc.  "Donating" - companies are donating money, facilities, employee time, as well as products and services, to governments and health organisations to help them tackle the crisis. For example, donating $X million to relevant charites, making now-empty buildings available for health worker training, giving products and services to organisations working on care, treatment, etc.  Both labels describe their respective activities well, but they overlap too much. Can I replace one with an alternative that reduces this overlap? The best I've come up with so far is to replace "giving" with "subsidising", but that seems a little flaccid in comparison. This is for a business audience and should be clear, impactful, easy to read, etc.  The following thread is close, but doesn't quite answer my question ("Bestowing" may be the best option in that thread, but again is too similar to "donating", and is also a little archaic for my purposes):


What actually are compilers and what differences do they have?

I know there are a lot of compilers for LaTeX, but I actually have never bothered changing it and now I'm used to pdflatex. But how are the others compilers different from it? Do they require different syntax or packages? It's not even fully clear to me what compilers actually are and what practically and technically means to use one compiler instead of another.


I want to split a long equation in many lines

I have a long line in equation. I want to split it properly in two or three lines. I've been using \begin{split} and \end{split}, but still it is not in good position. The equation's code is below.  \begin{equation} \begin{split} \frac{r(r-1)c_{0}}{z} + \\ &  \sum_{0}^{\infty}[[(j+r)(j+r+1)c_{j+1} - [(j+r)(j+r-1) - l(l+1)]c_{j}] \\ &= 0, \end{split} \end{equation}


Term for adjectives attached after names

What is the term for adjectives attached after names? For example, there is terrible in Ivan the Terrible. Are these counted as post-positive adjectives?


Mathematical Induction question Using $n\ge t\ge 0$

Let $n\geq t\geq 0$. Show that $$\sum_{j=t}^{n}\binom{j}{t}=\binom{n+1}{t+1}$$   I am stuck on this question. The fact thats it is multivariable is confusing me.


Why is round() returning a wrong answer and how do I fix it?

I'm trying to solve a simple challenge that requires the code to return numbers (floats) rounded to 1 decimal point(s). The code is actually working but it seems that round() is not returning the correct result.  For example, the answer to one of the test cases I'm getting is 45357.45. When rounded to the first decimal, this should be 45357.5. But using round() is still returning 45357.4. I tested with the following numbers and I'm getting mixed results:  # Correct print(round(5.45, 1)) 5.5  # Incorrect print(round(5674.45, 1)) 5674.4   Why would this happen and is there a way to fix it?


How is it that the inhabitants of angel one know of the federation when they have a policy on not making first contact until warp drive os established (TNG: first contact). Data says their level of technology is similar to mid 20 century on Earth, we were no way near establishing antimatter.


How to solve "Exception in thread "main" java.lang.NullPointerException"

I'm supposed to instantiate an object by passing a double array containing values and invoke some methods and the results should come out on the console. My code:  public class Client {      public static void main(String[] args) {         RainLog log = new RainLog(1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0,9.0,10.0);         double[] inRangeValues = log.getInRange(0,0);         for(int i=0; i<inRangeValues.length; i++)         System.out.println(inRangeValues[i]);   } }   after running this appears on the console:   Exception in thread "main" java.lang.NullPointerException at comp125.RainLog.getInRange(RainLog.java:73) at comp125.Client.main(Client.java:7)   I click on:  at comp125.RainLog.getInRange(RainLog.java:73)   it directs me to my loop:  for(int i=0; i<data.length; i++)   which passed the JUnit test which I am not sure why. I am new to java and programming so not really sure where the problem is at.


How to hide C# application from taskmanager processtab?

I need to hide my C# application from process tab of Taskmanager  using  this.ShowInTaskbar = false;    I have hide it from application tab. Now I need to hide it from process tab.  Is this possible?.


Why doesn't the deuterium nucleus have spin $0$?

A deuterium nucleus is composed of a proton and a neutron. Both have spin $\tfrac12$ so I would expect the deuterium to have two possible spins: $1$ for the triplet and $0$ for the singlet. But apparently deuterium always has spin $1$ and the spin $0$ state doesn't exist. Why?


I rendered an animation and then placed it into the video sequence editor to test it, and rendered that as a video.  Now I want to render a second animation (in other words, keep working), but when I press render animation, it's still using the sequence render option? (Rendering it as pngs). I was wondering how to switch between sequence render and animation render properly?


we develop a cloud software and we have the problem with loading javascript in Chrome. We change a javascript file on our server, but some users' chrome does not load this and keeps working with an old version that is not compatible.   I am not able to explain 1.000 users how they can delete cache. CTRL+F5 does not work. What can I set to tell Chrome: "Hey, there is a new version!"? Any help?  We compile assets (javascript).


I'm trying to make a simple directory tree representation in LaTeX. Something like:  spam  |  +-- ham  +-- eggs      |      +-- more spam      +-- dead parrots   The tree won't be that long (say, 10--15 entries or so), with three or so levels, and is a one-off thing. So, quick-and-dirty solutions are welcome. When recommending tikz, please note that I have almost no experience with it, so I'd appreciate a clean simple solution, even if it doesn't look quite perfect.   On Tex.SE tikz is almost like the jquery recurring joke on StackOverflow..    Edit: As per Thorsten's suggestion,  is a nice and easy-to-use solution. The example from above could be written as:  \usepackage{dirtree} ... \dirtree{% .1 spam. .2 ham. .2 eggs. .3 more spam. .3 dead parrots. }


How to applying css style into an iframe content?

I am trying to apply a CSS style for content inside the iframe, please check this link   jQuery:  $(document).ready(function() {     $('iframe').contents().find('h1').css('color','red'); });   HTML:  <iframe src="mysite" width="100%" height="100%" id="myframe"></iframe>   For iframe source I have used a live website.


When I add this text:  The pdpotri routine computes the inverse of a real symmetric or complex Hermitian positive definite distributed matrix $sub(A) = A(ia:ia+n-1, ja:ja+n-1)$ using the Cholesky factorization $sub(A) = UH*U or sub(A) = L*LH$ computed by pdpotrf.   to my .tex, I get this:  LaTeX Warning: `h' float specifier changed to `ht'.   If I remove it, it goes away. If I remove only the match mode (the dollar signs), the warning is still alive. The document has sections and subsections, if that helps. It also has many math inside it. I am trying to produce a minor example...  How to get rid of this warning?    EDIT  Check first comment of Gonzalo!


When I duplicate an object with Shift+D and then change color it also change the color on the original object. Same if I duplicate with Alt+D. I use Mac if that would matter. Would be happy for any help here since it is very enoying. /Peter


Difference between escape velocity and speed

What is the difference between escape velocity and escape speed , is their any error if we use them interchangeably?


How can you procedurally dismember a character model?

For example in the new Doom, you can use a chain saw and slash an enemy apart, the enemy actually splits in half in the path of the chain saw. I know how to do the cheap effects where you store a copy of an already chopped up model and then when you kill the enemy it's replaced with the chopped up model. But the real good ones, like in Doom or Shadow Warrior, split depending on how you slash it. How do they do that? I've been searching this on google for the past year, and I haven't found many tutorials or articles on it. Please help!  Example:


$f(x)$ is a differentiable function on the real line such that $ \lim_{x\to \infty } f(x) =1 $  and $ \lim_{x\to \infty } f'(x) = s $ .Then   $s$ should be $0$ $s$ need not be $0$ but $|s| < 1$ $s > 1$ $s < -1$   Because $f(x)$ is bounded need not mean it can neither be increasing nor decreasing.So the derivative needs not be $0$.


Using induction or otherwise, show that the polynomial  $$P_{n}(x)=1+x+\frac{x^{2}}{2}+\cdots+\frac{x^{n}}{n!}$$  has exactly one real zero if $n$ is odd and none if $n$ is even.  I believe the key here is that $P_{n}'(x)=P_{n-1}(x)$, but I cannot see how to apply this to the problem.


I am trying to form functions from $[0,1)$ to different sets. first one was continuous surjection from $[0,1)$ to $R$. little modification of sinusoidal exponential function will satisfy the requirement. but for bijection from $[0,1)$ to $R$, I am not able to come up with any function. Is it possible? bijection doesn't have to be continuous.


What's the word for "believing one is the center of the universe"?

I want to describe a character who thinks that the world revolves around him, thus he believes he is the center of the universe.   Is there a single word having the meaning of center of (one's) universe?


Is there a standard for multiple DHCP servers?

Is there a standard that allows a device on a network to have its own DHCP server that only gets turned on if there is no other DHCP server on the network? I'm sure it's possible to implement one using dhcp_probe but I was wondering if there's a pre-existing way of doing this.


Still discovering Ubuntu on my Mac, I would like to know how to change the behaviour of my keyboard and use cmd as the super key (and do stuff like cmd+c for copy).  I'm using a 2010 white Macbook with Ubuntu 16.04.  I have read somewhere that in previous Ubuntu versions there were something to activate in the settings like "Use win command as Super" but correct me if I'm wrong, it's not in Ubuntu 16.04 ?


Code spanning over two pages with minted, inside listing with caption

I am trying using minted to display some code in my document, but the code is long and spans over two pages, this works fine, however when I place my code inside  \begin{listing}   \inputminted{java}{code/JavaCode.java}   \caption{Some caption}   \label{label1} \end{listing}   Then my code doesn't show up and I get the warning:     LaTeX Warning: Float too large for page   I have tried using the option H in listing, but then the code shows in only one page and it doesn't fit so I only see a part of it.  I also tried with the code directly in the latex document ie:  \begin{listing}   \begin{minted}{java}      Java code   \end{minted}   \caption{Some caption}   \label{label1} \end{listing}   But the same happens, any ideas?


Two neighborhoods of $0$ in the plane and the upper half plane (resp.) cannot be diffeomorphic.

Let $\mathbb{R^2}$ be equipped with the standard topology, and let $\mathbb{H^2}$ be the upper half plane (containing the x-axis), equipped with the subspace topology. Let $U$ be an open neighborhood of $0$ in $\mathbb{R^2}$, $V$ an open neighborhood of $0$ in $\mathbb{H^2}$. How can I show that $U$ and $V$ are not diffeomorphic? My guess is that I should proceed by contradiction, and suppose that there is a diffeomorphism from U onto V. I feel like there will be an issue with the pre-image of a semi open ball centered at $0$, which should be open in $\mathbb{R^2}$. But I struggle to prove that properly.


Black turns transparent in Blender texture

My texture has some black text (on right side of picture,) and also a transparent background. But the text also is transparent?!? Plus I must keep the text black.  Picture:  Please help.


Can you do a partial checkout with Subversion?

If I had 20 directories under trunk/ with lots of files in each and only needed 3 of those directories, would it be possible to do a Subversion checkout with only those 3 directories under trunk?


Can some one please help me write an ls command to list files starting with abc (abc*.txt) and exclude the ones containing _DEL_ in the name (abc*_DEL*.txt)  I am trying something like this:  ls abc*.txt --ignore "abc*_DEL_*.xt"


Can I transfer game progress for Clash of Clans between GameCenter accounts

I downloaded clash of clans on my sisters apple account. I then made my own apple account. When I try purchasing gems I can't because it says something about the app not being downloaded from this apple account.  Is there a way I can't delete clash of clans and then re download it without losing any progress?!! Please help!! I also have a gamecenter account.


Install Steam and most games in one large HDD but some popular games on a separate SSD

I have a 1 TB HDD and a 120 GB SSD. On the HDD I have all my data along with Steam and—currently—all my games. On the SSD I have Windows 7 and programs, but there's 50 GB of unused space that I wish to use for the games I most commonly play on Steam (for quicker loading times, etc).  To summarize, I want to have this situation:   120GB SSD (C:\): Windows, programs, and a few Steam games. 1TB HDD (D:\): data, Steam, and most games.   Is this possible? If not, what other choices do I have to do something similar?


I want to show that $\sin(\frac{x}{2})(\sin(x)+\sin(2x)+...+\sin(nx))=\sin(\frac{nx}{2})\sin(\frac{n+1}{2}x)$  But I'm not quite sure how to start my proof. I tried to expand the left half of the equation but that didn't seem to be the right idea. Help appreciated!


Hi All I've restarted my pc but when I check my connection at the top right corner I no longer can see the wifi icon the problem at start with that the cursor of my mouse doesn't want to move when I use the touch pad so I restarted my pc then that's what happen  the wifi section in setting has also gone  I don't know what to do I tried to restart my pc one more time but no use the problem still occurer when I run lspci -knn | grep Net -A3; uname -r it give me the following output: 02:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM43142 802.11b/g/n [14e4:4365] (rev 01)     Subsystem: Hewlett-Packard Company BCM43142 802.11b/g/n [103c:804a]     Kernel driver in use: bcma-pci-bridge     Kernel modules: bcma 5.8.0-36-generic


Proof of the inequality $||a+b|^p - |a|^p| \leq \epsilon |a|^p + C_{\epsilon} |b|^p$

In , the following theorem is used implicitly (see Example (a) on page 488):     Let $0<p<\infty$. For every $\epsilon > 0$, there exists some $C_{\epsilon} > 0$ such that $\forall a,b \in \mathbb{C}$:   $$ \left||a+b|^p - |a|^p \right| \leq \epsilon |a|^p + C_{\epsilon} |b|^p $$   Is this a well-known result? I would like to know its proof, and its name if it has one. Can someone point me towards a reference to this result which includes a proof, or give me a proof outline?  I've tried using Jensen's Inequality for the case $p>1, a,b>0$, but it doesn't seem to work out.


How to get rid of those edges?    When i try to disolve them loop cut stops working properly.


Difference between two declarations involving a pointer and an array

What is the difference between int *a[3] and int (*a)[3]?


Filter an IQueryable with case insensitive.

IQueryable<MyModel> myList = GetListMyModel().AsQueryable(); myList = myList.Where(m => m.Name.Contains('John'));   I want to return everything with Name = 'John' or 'john' or 'JOHN' (case-insensitive)


Suppose I have matrices $A,B\in\mathrm{Mat}_n(\mathbf{R})$ which are conjugate in $\mathrm{Mat}_n(\mathbf{C})$ in the sense that there is $S\in\mathrm{GL}_n(\mathbf{C})$ with $A=SBS^{-1}$. Then is it possible to choose $S$ with this property and $S\in\mathrm{GL}_n(\mathbf{R})$?  this fact is claimed in the answers to


Would a backpack or cargo rack be better for commuting?

Right now I use a backpack to hold all of my supplies including spare tubes, pump, patch kits, tools, my change of clothes for work, etc.  This is the backpack I use:    It's about as comfortable as a backpack can get without getting into the hiking backpacks with frames. Altogether I would say it weighs no more than 10 lbs max. The muscles in my back get slightly irritated during my commute.  Would it be more comfortable to use a rear cargo rack on my bike instead? Will adding more weight to the bike change how the bike rides and feels?  EDIT: After doing some research I came across  that explains the different methods of carrying your gear on commutes and how it affects your body. It's worth a look.  EDIT #2: Having tried both for a couple of weeks now, I can say that (for me personally) the backpack is the better way to go given the relatively light weight I have to carry.  If you do use a backpack, make sure that the straps are tightened enough so that it's positioned higher up on your back and to the point to where there is little to no movement on your back. This makes a world of difference when it comes to comfort.


I`m unable to terminate process by SIGKILL signal.   $ ps aux | grep -i phps username 17564   0.0  0.0        0      0   ??  ?E   Sun09AM   0:00.00 (phpstorm) username 27664   0.0  0.0  2442020    788 s000  S+   11:53AM   0:00.00 grep -i phps $ sudo kill -9 17564 $ ps aux | grep -i phps username 17564   0.0  0.0        0      0   ??  ?E   Sun09AM   0:00.00 (phpstorm) username 27883   0.0  0.0  2423392    312 s000  R+   11:55AM   0:00.00 grep -i phps   What does it mean that process in parentheses? How to kill it?


Copy all folders in a library to another library

I have a Sharepoint library which is having 10 folders, i want to move those folders(along with files inside those folders) from one library to another library with in same site using CSOM**(C#)**. Please help me out.


Can a human size object move so fast that it ceases to be observable?

In many anime, comics, movies, etc, we see a lot of super human beings moving and fighting at such high speeds that a regular human being cannot see that they are fighting or moving pass by.  In particular, in the first battle between Goku and Piccolo, those two are able to fight in a confined environment (when Piccolo first appears in the comics, stage fight, if I remembered correctly), and regular audiences are unable to see them when they battle.   Is it physically possible for a "human" (human size object) to move in a confined environment (let's say, $20~\text{m} \times 20~\text{m} \times 10~\text{m}$ ) so fast that a normal person would be unable to see it? If it is possible, how fast must this "person" be?  Assume that this "human" cannot move faster than, or even close to the speed of light.  Some clarifications:  First, please ignore the strength/physicality of the object, and consider it an object that can can move "freely" in this confined space without causing any "side effects" (such as heat, sounds, etc)  Second, please take in note that the object is moving in a confined, rather small 3D space as mentioned in the question, and the observer would be always able to see the entire space.   And last, a blurred image would be considered as "able to see".


Until this day, for each interaction with the SO Site, I received my reputation points at the same moment of the interaction. For example, when suggested edition was accepted, my reputation would increase by two points at the same moment. It seems to me that my reputation stood today, even though I suggested edits and they were accepted. Does anyone know what might be happening?


Is there a metric on the reals $\Bbb R$ so that a subset of $\Bbb R$ is open iff its complement is finite?

I wanted to know if there is a distance function $d$ on $\Bbb R$ so that a nonempty subset $U$ of $\Bbb R$ is open with respect to $d$ if and only if its complement $\Bbb R$ \ U is finite ?


Why was it necessary for Lady Olena, Peter Baelesh and Ser Dontos to conspire together to give Sansa a necklace containing poison?   Given that Lady Olena was essentially just pouring poison in to Joffrey's drink - couldn't she have just had the poison kept in her handbag or something?   Why to the contrived effort to involve a necklace and other person?   I'm interested in answers concerning both the TV show and the books.


Can a black hole absorb photons whose wavelengths are greater than the BH horizon size?

I am wondering whether a black hole can absorb photons whose wavelengths are greater than the horizon size of the black hole. I have seen different contradicting opinions on the answer. For instance , the accepted answer claims that the answer is no, without giving any justification whatsoever. While on , I think all the answers are pointing that yes, a black hole should be able to absorb photons whose wavelengths are greater than the size of the horizon of the black hole.  If the answer is yes, then black holes are perfect blackbodies, right? Or is it more complicated, because, like some answer on physicsforums claim, a black hole might have only a small probability to absorb photons whose wavelengths are greater than the horizon size (though no mathematical justification is given), thus even though it might be possible for a BH to absorb such photons, it might still not be a blackbody.  Edit: Here's what I've been told by a QFT specialist:      I think your question is not answerable. "A single photon" requires   knowing how to quantize the EM field near a black hole. That is an   open problem. And also, "single" particles don't objectively exist in   accelerated frames. See the Unruh effect.   I am not satisfied with the current two answers. They do not deal with the above comment at all. Furthermore they seem to contradict each other and they aren't crystal clear.


Is the Edo god (or Edo lord, from "Justice") a ship? Or is it a space organism of some kind, like Gomtuu? Is it more than one entity?


How do I use a  tag in a table that does not wrap?

On my Docusaurus page, I have markup like this that renders the following screenshot:

     Name	     Description

     organizationName	     The GitHub user or organization that owns the repository. In the case of Docusaurus, that would be the "facebook" GitHub organization.

     projectName	     The name of the GitHub repository for your project. For example, Docusaurus is hosted at https://github.com/facebook/docusaurus, so our project name in this case would be "docusaurus".

     Note that the first table column are wrapped. I prefer them to not be wrapped so that it is easier to read. How do I make the  block level such that it does not wrap?


I've tried solving it by parts but ended with a loop. And I can´t remember another method.  Thanks.


What does the bracketed capital letter indicate in the revised version below? Is it essential, per the rules of proper punctuation, to do so? Are the ellipsis points (i.e., the spacing of the dots) spot on in that sentence to indicate the omission of one or more sentences?  Original quotation  "It need hardly be said that shortness is a merit in words. There are often reasons why shortness is not possible; much less often there are occasions when length, not shortness, is desirable. But it is a general truth that the short words are not only handier to use, but more possible in effect; extra syllables reduce, not increase, vigor."  Revised quotation  "It need hardly be said that shortness is a merit in words. . . . [S]hort words are not only handier to use, but more possible in effect; extra syllables reduce, not increase, vigor."  Thank you.


Crashed due to: Caused by: java.lang.NullPointerException

I am trying to build a feature within a ROM, the build completes without any isseu and the feature is working, however when i want to open it's settings it force closes.   I have made a logcat:  E/AndroidRuntime( 3440): Caused by: java.lang.NullPointerException E/AndroidRuntime( 3440):    at com.android.settings.mahdi.aokp.ProgressBar.onCreate(ProgressBar.java:86)   And this is the corresponding lines in ProgressBar.java:      mprogressbar_speed = (SeekBarPreference) findPreference(PROGRESSBAR_SPEED);     mprogressbar_speed.setValue(Settings.System.getInt(getContentResolver(), <---- this is line 86                                 Settings.System.PROGRESSBAR_SPEED, 4));     mprogressbar_speed.setOnPreferenceChangeListener(this);   I dont know how to resolve this isseu and i can use some help...  Thanks in advance...


There's a discrepancy between the number of starred messages reported at different places

In the C++ , the number of all starred messages is currently reported in the right-hand panel as 3407. That number is a link, and if I click on it, it takes me to [an info page with a tab saying 5.9k stars.   I'm sure there is an explanation for this discrepancy, but I'd like to think it is a bug no matter what the explanation is.


What ratio scales do Google Maps zoom levels correspond to?

Can anyone provide me with a link (or some details) on the actual ratio to "zoom level" figures for Google Maps?  e.g. Google Maps Level 13 = 1:20000


The word "thou" (and similar variations of the Latin tu in other languages) was used between people for informal speech, and talking to people of lower standing.  So why did people use it (most prominently, in the King James Version of the Bible) to address God? If anything, I'd think speaking in humble deference to one's deity would definitely require one to use "you".


So as the title says, I need to promote a standalone Win2008R2 server to a Domain Controller, and I don't a DNS Server (I think), as there will be no clients connected to the domain, it will be only used for Remote Desktop Services. Yes, I know, it's considered bad practice to install other roles on the DC, but in this case, it's necessary.  Do I need to install the DNS Server, and if I do, how to make it as transparent as possible?  EDIT: Seems that I need to install the DNS Server, so I can I configure it not to mess up my entire domain?  For example:  The server I need to promote is rdc.mydomain.com, and it has an A entry to it's IP in the current DNS, while other servers under mydomain.com are running Linux and don't need to know anything about this Windows box. The domain uses a third-party DNS and all edits and updates need to be done via a separate web page, our servers don't have write/update access.


Is there a list of Windows special directories/shortcuts (like %TEMP%)?

I'm looking for a reference list of shortcuts like %TEMP%.  When I'm using Windows+R or Windows Explorer and type %temp%, the Windows Explorer takes me to the Temp directory. Are there more of these shortcuts?  UPDATE: .


Alright so kind of a long story, but basically I had a laptop with Windows 7 on it, and the hard drive failed. So I bought a cheap SSD and installed Ubuntu on it (because who wants to pay for windows for a test.) I've been using Ubuntu for a little bit now, and I'm just getting sick of it. I have no idea how to use the little terminal thing and whenever I want to install something I just copy and paste lines into it from whatever forum has an installation guide. I'm trying to upgrade back to Windows, but I can't seem to get anything to work. I bought a Windows 7 Home Premium Key, and I have an ISO downloaded on my computer, but I can't figure out how to format a USB stick to get it to boot. Is there any easy way to install Windows?  P.S. I don't need to backup anything on my computer, I have the few files that I need saved to my Google Drive, and I also don't want to do a dual-boot thing, just to switch completely from Ubuntu to Windows


How to process multiple command line arguments in Bash?

I am having problem allowing my script to take more than three arguments. My script will take commands like this, for example:  ./myscript.sh -i -v -r filename   so far if it only takes two arguments plus filename:   ./myscript.sh -i -v filename  If I run the full commands, [-i] [-v] [-r] it gives this errors...  "mv: invalid option -- 'r' Try 'mv --help' for more information."  here is my code so far....  #!/bin/bash  dirfile='.trash'  verbose=  function helpfunction() {     echo "=============== HELP COMMAND ============="     echo ""     echo "-h | --help"     echo "-i | --interactive"     echo "-v | --verbose"     echo "-r | --recursive"     echo "" }  if [ $# -eq 0 ]; then     echo "no commands"     exit 1 fi   option="${1}"  case ${option} in       -h | --help)             helpfunction             exit       ;;      #interactive -i or --interactive      -i) FILE="${*}"        echo "File name is $FILE"             echo -n "Do you want to remove this file (y/n)? "             read answer             if echo "$answer" | grep -iq "^y" ;then                 mv $FILE $dirfile             fi       ;;      #verbose -v or --verbose      -v) FILE="${*}"             if [ -f "$FILE" ]; then                 -v $FILE             fi       ;;      #recursive -r or --recursive      -r) FILE="${*}"             if [ -d "${*}" ]; then                 rm -r "$FILE"             fi       ;;      #unremove -u or --unremove         -u) FILE="${*}"                 for file in $dirfile*;                  do                     if [[ -f $file ]]; then                         echo "file found"                     else                         echo "File not found"                     fi                 done             ;;      #list -l or --list         -l) FILE="${*}"                 for entry in "$dirfile"/*                 do                     echo "$entry"                 done             ;;          *)             echo "`basename ${0}`:usage: [-f file] | [-d directory]"            exit 1 # Command to come out of the program with status 1            ;;  esac


Distribution of the square of a non-standard normal random variable

What is the distribution of the square of a non-standard normal random variable (i.e., the mean is not equal to 0 and the variance is not equal to 1)?


Change the default WordPress image on the dashboard login to a custom image

How do I change the default WordPress image on the dashboard login to a custom image?


Would particles in this container go over light speed?

Imagine a container which contains a speaker and gas at normal pressure inside. Now imagine it moving at almost light speed (maybe c-100m/s) if the speaker makes a sound, causing particles to move at the speed of sound. Would the particles moving parallel to the container’s movement move faster than light?  or is there something im missing here?


I would like to prevent Excel behavior that any large number I enter is stored as a number, then abbreviated to scientific notation. Is it possible to tell Excel 2007 to stop doing this?


I have just had my new PC delivered. I have a Macbook running and am now downloading the iso file. Do I need to follow the instructions on the  to create an OS X bootable usb and start the PC with it? Or is this only for installing Ubuntu on OS X machines? So what should I do in my case?


Is $\mathbb{Z}[\sqrt 2 , \sqrt 3]$ an integral domain?

Is $\mathbb{Z}[\sqrt 2 , \sqrt 3]$ an integral domain ?   I know that $\mathbb{Z}[\sqrt 2] $ is integral domain:   take  element $a + b\sqrt 2$ and rationalize it, but im confused about  $\mathbb{Z}[\sqrt 2 , \sqrt 3]$.


How to identify that you're running under a VM?

Is there a way to identify, from within a VM, that your code is running inside a VM?  I guess there are more or less easy ways to identify specific VM systems, especially if the VM has the provider's extensions installed (such as for VirtualBox or VMWare). But is there a general way to identify that you are not running directly on the CPU?


Let $a_n$ be a decreasing sequence of nonnegative real numbers. Prove that if $\sum a_n$ converges, then $na_n \to 0$. Hint: use that $n\, a_{2n} \le a_{n+1}+\cdots + a_{2n}$  I couldn't prove this using the given hint, could someone give me a few tips? I also have two more questions:  Suppose I have $2na_{2n},(2n+1)a_{2n+1}\to 0$ is that enough to say that $na_n\to 0$?  Is there any easy way to show $n \, a_{2n}\le a_{n+1}+\cdots + a_{2n}$, there's probably a simple inductive proof I couldn't get.


Where is the X.org config file? How do I configure X there?

As Ubuntu 10.10 seems to neither detect my graphics card (Intel 82852/855GM) automatically nor use the corresponding Intel driver even after manually installing it, I am looking into manually configuring X (shouldn't I?). Where can I find the configuration files I need to edit?


Are there arbitrarily large gaps between consecutive primes?

I made a program to find out the number of primes within a certain range, for example between $1$ and $10000$ I found $1229$ primes, I then increased my range to $20000$ and then I found $2262$ primes, after doing it for $1$ to $30000$, I found $3245$ primes.  Now a curious thing to notice is that each time, The probability of finding a prime in between $2$ multiples of $10000$ is decreasing, i.e it was $$\frac{2262-1229}{10000}=0.1033$$ between $10000$ and $20000$, and $$\frac{3245-2262}{10000}=0.0983$$ between $20000$ and $30000$,   So from this can we infer that there will exist two numbers separated by a gap of $10000$ such that no number in between them is prime? If so how to determine the first two numbers with which this happens? Also I took $10000$ just as a reference here, what about if the gap between them in general is $x$, can we do something for this in generality?  Thanks!


Problems with frying chicken...coating doesnt stick, and coating doesnt get crispy

Ive been trying to fry chicken in oil, but im running into issues with the coating.  Ive tried using a pre-made coating mix and flour. I coat the chicken in egg (which is supposed to help the coating to stick) then coat the chicken in the coating. But the coating struggles to stick to the chicken and falls off when i flip the chicken over. It also hardens and turns into solid pieces that stick to the bowl and which i cant use, which is a waste of the coating.  The coating doesnt get really crispy when I fry the chicken in oil either. It only gets mildly crispy, not like the crunchy type you get in restaurants or KFC's hot n spicy chicken.  The flour does get somewhat crunchier when fried though, compared to using the coating mix only.  Does anyone know why the coating mix/flour is struggling to stick to the chicken (even when I coat the chicken in egg first) and why its not getting really crispy?  Edit : Just tried to fry chicken again, didnt use egg this time. The coating didnt turn into hard pieces, but the coating didnt stick to the chicken. The flour/coating also mostly dissolved upon contact with the oil. Not sure what im doing wrong.


p-value definition and inadequacy of tail events

Wikipedia defines p-values as      (The probability of obtaining a test statistic) equal to or more extreme than what was actually observed   For starters, usage of extreme there is subjective. To make matters more concrete,      $Pr ( X ≥ x | H )$ for right tail event   $Pr ( X ≤ x | H )$ for left tail event   $2 min \{ Pr ( X ≤ x | H ) , Pr ( X ≥ x | H ) \} $ for double tail event.   This diagram explains it for a right tailed event:   Now these definitions work well for normal distribution, t distribution, F distribution, and chi-square distributions.  But consider a bimodal distribution.        ⏜       ⏜    /   \    /   \   /     \_/     |\  /              | \                 x   For the observation x, won't we also have to consider the middle region  as "extreme values" since their probability is low? So our extreme region will look something like the shaded region in:       ⏜       ⏜    /   \    /   \   /|    |\_/|   |\  /.|    |...|   |.\                 x   In this case we can't just consider tailed events. What exactly is the definition of "extreme values" then?


How does the 2009 Star Trek film mesh with Enterprise canon?

All of the events in the 2009 Star Trek movie would have taken place after the adventures of Captain Johnathan Archer and company.  So, unless J.J. Abrams and friends decide to completely hand-wave that bit of history as well, all of the events in Enterprise should (in theory) still be able to line up with this new timeline.  Are there any points of conflict in this?  How about any time-travel episodes in the Enterprise series which may have happened differently after the interventions of Nero?  Are there possible good explanations for such conflicts, or are there some which are irreconcilable?  NOTE:  I'm not arguing here whether or not ST2k9 is a part of Star Trek canon.  In fact, this question is specifically granting that it is.  I just want to know if there's any conflicts between the new movie and the existing Star Trek history that remains applicable to it.


Is there any way to undo the sudo within the script? like..  sudo ./script.sh   commands 1,2,3,4,5 with sudo rights  commands 6,7,8,9 without sudo rights


Convert images from JPGS to PDFS with the terminal

Good morning, is there a way to convert image formats such as PNG, JPG to PDF using the terminal? Would appreciate an answer very much.


How does @autowired annotation works for a private field?

How does @Autowired annotation work for a private field without a getter and a setter? How can spring access a private field?


18.04: Ubuntu installation fails on windows 7

there I'm trying to installing Ubuntu 18.04 LTS on HP Pavilion G series notebook but it shows message of faulty DVD/CD ..etc. And not installing please help me....


Cannot install .NET Framework 3.5 on Windows 10

I'm about to give up on installing .NET 3.5. I've tried almost everything now, but nothing seems to work.   Installing .NET 3.5 from my Windows USB installation via CMD doesn't work, it simply freezes after Image Version: 10.0.10240.16384 (Command used: dism.exe /online /enable-feature /featurename:NetFX3 /All /Source:D:\sources\sxs /LimitAccess). I have also tried copying the sources folder to my C drive and run the command, without succes. It should be noted that Dism.exe /online /Cleanup-Image /StartComponentCleanup freezes at the exact same moment. Microsoft's installer doesn't work either. If I click the 'Install this feature' button it is stuck at the first phase (Where it's searching for the correct files if I remember correctly) It cannot be enabled via the control panel, because it doesn't show up there. (This might be a related issue) I cannot search for new updates, for some reason it just keeps searching without finding something or stopping. Nevermind, it found updates after ~2 hours.   I do not get any errors in all the ways that I've tried mentioned above.


Can I get better prices for items by trading with different people

I haven't upgraded barter much in Skyrim and I was wondering if that was the only way to get better prices for my loot or if nobles might spend more money for jewlerry or armour


Why did Littlefinger give Sansa to the Boltons?

This question is about the TV show only.  In the books, Sansa is still with Littlefinger and everything that happens between Sansa and Ramsay in the show actually takes place between Ramsay and Jeyne Poole in the books.  However I don't recall why Littlefinger sends Sansa north. Apparently, in the books, it's safer to keep her traveling. So why did he do it in the show?


Any risk in recompiling all Apex classes in org?

Running into an issue with a deployment, getting a ton of errors of the following flavor: line -1, column -1: Dependent class is invalid and needs recompilation: Class MeansRegisterCustomerTest : Constructor not defined: [LightningLoginFormController.VerifyResponse].<Constructor>() Stack Trace: null Seems like the 'Compile all classes' option in Apex settings has worked for people with similar issues. Is there any risk in recompiling all Apex classes? I don't see how this could break something that was not already broken, but would like to hear people's thoughts on this before potentially breaking a bunch of code.


Can a naked eye see a single atom when it is resonantly driven by some laser beam?

Presumably, when the laser is strong enough, the fluorescence will be very strong too. So, is it possible to see a single atom with a naked eye?


I found , but it made me confused. I received my MacBook Pro yesterday. After unboxing, I used it for some time and then I fully charged the battery. I will be using this laptop as my primary device.  So, my question is, if I use my MacBook about 7-8 hours a day with the charger plugged in, will it be harmful for the battery? What is the recommended way?


Mac mini set to never sleep, but seems to be sleeping anyway (does not respond to network)

I've enabled SSH into my mac mini (late 2012 running OS X 10.9.3), and have the energy saver settings set so that the display sleeps after 10 minutes, and the computer is set to never sleep.  If the mac goes unused for a while, then I try SSH into it, the SSH connection is refused. If I go bang on the keyboard or mouse to wake up the mac, then the SSH connection is accepted and it works.  This appears as though the mac is ignoring my energy saver settings and is in fact sleeping when it shouldn't be.  Is there anything I can do to fix this? Is there anything to look for in console to verify if it is actually sleeping?  Thanks


The selection toggle arrows in the Outliner disappeared. Is there some preference in the settings that has to be turned on?


What would a Cayley table of inverse semigroup look like?

I tried to construct a Cayley table of an algebraic structure called inverse semigroup. No success so far. I just end up with more complicated structure (monoid, group). Thank you kindly. I may think, that this phrasing is more accurate and more to the point. Also, I have checked many sources and didn't find an example... One possibility would be, that it is not possible (which I doubt). Or why would it be not possible? One chance is to try for any set $X$, let $I(X)$ be the set of all partial bijections on $X \to X$, i.e. bijections between subsets of $X \to X$. The composite of partial bijections is their composite as relations (or as partial functions). In fact, any inverse semigroup is isomorphic to a sub-inverse-semigroup.


What is a real example of Request scope usage in ColdFusion?  From :     Request   The Request scope is used for the current request. These   variables are non-persistent global variables.   Is it like the request object in JEE?  Thanks in advance.


Possible Duplicate:          There are a lot of really screwed up configurations out there, because people didn't take a minute to sit down and think about something as simple as the name for their Active Directory forest. I'm asking this question to self-answer so that this knowledge can be more readily available. If you think you have a better answer, by all means add your input (but be prepared to defend it!)   So, what should I name my new Active Directory?


I need to send email via my C# app. I come from a VB 6 background and had a lot of bad experiences with the MAPI control. First of all, MAPI did not support HTML emails and second, all the emails were sent to my default mail outbox. So I still needed to click on send receive. If I needed to send bulk html bodied emails (100 - 200), what would be the best way to do this in C#?


What is the optimal value of the -j flag for make ?  I know that all my source is free of errors.  Is it the number of cores?  Or the number of logical processors?


Which of the following is correct?     The data was kept in soft form.   The data were kept in soft form.


I destroyed blocks and traps inside the jungle temple and defeated the golem after that the lunatic cultist won't spawn.


Proof Help: In a group $G$, there exists a $g$ such that $g^2 = e$

I'm working through an Abstract Algebra book to teach myself, and came across the problem:  Prove: If $G$ is a finite group of even order, then there exists a $g\in G$ such that $g^2 = e$ and $g \ne e$.  (In this book, $e$ is used as the identity element.  I don't know if that's standard or not...) I have a proof outline, but don't really know how to write it in a formal way.  My idea is as follows:  First, note that this problem is equivalent to saying that "there exists a $g\in G$ such that $g = g^{-1}$.  Also note that the identity element is its own inverse. Since the identity element is its own inverse, we have an odd number of elements remaining in the group that need their inverse "assigned."  Assign all but one of the remaining elements an inverse so that none satisfy $g = g^{-1}$. You have one remaining element left; the rest of the elements already have inverses.  As inverses are unique, this element must be its own inverse.  My question is twofold:  Am I even close to being on the right track as far as a proof outline goes? If so, what can I do to make this proof rigorous, and not just an outline?


Expected Sum of n numbers after m random opeartions on n numbers.

I have been given $25$ objects numbered from $1$ to $25$ and a set $S = \{-2, -1, 0, 1, 2\}$. I have to choose a random number from the given set and add it to all the objects. I have to do this $5$ times. What will be the expected sum of all objects after all $5$ turns?


Say I'm talking to a friend about a particular sound, then I tell him I will show him what I mean. Is there a way to say show without implying visual demonstration? I guess maybe play? Any other suggestions?


when i log in to my Ubuntu 12.04.4 LTS it takes me immediately back to my log in screen

When i log in to my Ubuntu 12.04.4 LTS it takes me immediately back to my log in screen. This behavior began when I pressed the power button during installation of updates (to a new version of Ubuntu) somewhere around June or July of this year. If I type the wrong password it says "incorrect login". If I type the correct password, it goes black for a second then comes back to the log in page again. The log in page looks completely different than it used to under Ubuntu 12.04.4 LTS. When I press    and then log in it just says incorrect login over and over again no matter what.


Iteration converges $x_{n+1}=\cos x_n$ for any $x_0\in \Bbb R$

How do I prove that iteration $x_{n+1}=\cos x_n$ converges for any $x_0\in \Bbb R$ ?


How do I to resolve unmet dependencies to uninstall and reinstall package

I have tried several askubuntu threads but yet to no avail none have all met qualifications.   I installed allvideodownloader, and found a better version an earlier version; I downloaded from software-center, so there should not have been a related programs version problem and I got this error:  The following packages have unmet dependencies:  allvideodownloader : Depends: allvideodownloader-bin (= 2.6.0-0ubuntu1)  apache2.2-bin : Depends: libaprutil1-ldap but it is not going to be installed E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.   I have tried the usual suspects, in synaptic, software-center and aptitude.   apt-get autoremove --purge allvideodownloader Package allvideodownloader is not installed, so not removed 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded   apt-get remove --auto-remove allvideodownloader-bin Package allvideodownloader is not installed, so not removed 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded   apt-get remove --auto-remove allvideodownloader-bin E Unable to locate package allvideoinstaller-bin   sudo apt-get install allvideoinstaller-bin E Unable to locate package allvideoinstaller-bin   This is what I believe to be so; allvideodownloader changed the versions on several packages at install and didn't change them back at uninstall. These packages are somehow not reverse compatible using usual means.  I am having a headache I am growing used to from staring at this problem and that wont help matters. I've tried manner of install , purge and repair of broken packages   Please advise me on a repair.  thx,  DL


How to make a icon in desktop for a script

I want to have icon on desktop  of my script so that whenever I click that icon my script runs.


MySQL and PHPMyAdmin issue: locked out cant get back in

I am trying to change my password with mysql, and I am not a smart man...  I have done google search after google search, and done everything I can to resolve the issue.  I am on Ubuntu 16.04, if that helps at all.  I type the command:  $ mysqladmin -u root password newpass   and I get:  mysqladmin: connect to server at 'localhost' failed error:  'Can't connect to local MySQL server through socket /var/run/mysqld/mysqld.sock' (2)'  Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists!   Any suggestions?  Also, I recently had followed some directions to add password to phpmyadmin from .  This is what caused me to have the issue that I am trying to resolve, if that makes sense at all.  Any help would be greatly appreciated.  Edit:  sudo service start mysql   produced:  start: unrecognized service   Tried this instead:   service mysql start   and it started. then tested the status using:  service mysql status   produced:  ● mysql.service - LSB: Start and stop the mysql database server daemon Loaded: loaded (/etc/init.d/mysql; bad; vendor preset: enabled) Active: active (exited) since Fri 2017-01-06 12:17:04 CST; 2h 38min ago Docs: man:systemd-sysv-generator(8)   Edit 2:   sudo service mysql stop && sudo service mysql start && sudo service     mysql status  [sudo] password for logan:   ● mysql.service - LSB: Start and stop the mysql database server      daemon  Loaded: loaded (/etc/init.d/mysql; bad; vendor preset: enabled)  Active: active (exited) since Mon 2017-01-09 09:11:39 CST; 16ms ago  Docs: man:systemd-sysv-generator(8)  Process: 6014 ExecStop=/etc/init.d/mysql stop (code=exited,      status=0/SUCCESS)  Process: 6050 ExecStart=/etc/init.d/mysql start (code=exited,     status=0/SUCCESS   Jan 09 09:11:39 logan-Latitude-E6320 systemd[1]: Starting LSB: Start and stop th  Jan 09 09:11:39 logan-Latitude-E6320 systemd[1]: Started LSB: Start and stop the   Edit 3:  I tried another method, hopefully this information is useful...  logan@logan-Latitude-E6320:~$ ps -ef | grep mysql logan     8096  7119  0 13:21 pts/1    00:00:00 grep --color=auto mysql root     19832  1244  0 Jan06 ?        00:00:00 /bin/sh     /opt/lampp/bin/mysqld_safe --datadir=/opt/lampp/var/mysql --pid-    file=/opt/lampp/var/mysql/logan-Latitude-E6320.pid mysql    19975 19832  0 Jan06 ?        00:00:10 /opt/lampp/sbin/mysqld     --basedir=/opt/lampp --datadir=/opt/lampp/var/mysql --plugin-    dir=/opt/lampp/lib/mysql/plugin/ --user=mysql --log-     error=/opt/lampp/var/mysql/logan-Latitude-E6320.err --pid-     file=/opt/lampp/var/mysql/logan-Latitude-E6320.pid --    socket=/opt/lampp/var/mysql/mysql.sock --port=3306


What is most important in building a regression model?

When I build a regression model, which is considered most important:   removing insignificant variables, checking jfor multicollinearity and removing those variables that contribute to it, multiple R-Squared, or something else?   If I have to take care of all of the above, what should be my order of preference?  If I want to evaluate the model, is there is hard and fast rule that says residuals should be normally distributed?


How to deal with perfect separation in logistic regression?

If you have a variable which perfectly separates zeroes and ones in target variable, R will yield the following "perfect or quasi perfect separation" warning message:  Warning message: glm.fit: fitted probabilities numerically 0 or 1 occurred    We still get the model but the coefficient estimates are inflated.   How do you deal with this in practice?


In Westworld, what powers the hosts? Do they need a "recharge" every now and then?

In Westworld, what's the underlying power source for the hosts?  Do they digest food like humans to generate calories?  I think this is especially important to know in S2.


Conditional sentences not starting with "if"

Were I rich, I would live on Long Island.   If I were rich, I would live on Long Island.   Is the first sentence still used, or is used in particular contexts (in example, to give emphasis to the sentence)?


How does a computer chip read code, interpret it, and convert it into action?

I understand that binary is effectively functioning as a “virtual representation” of low voltage and high voltage. However, I do not understand how the instruction set to MAKE the voltage high or low is being executed. Within a computer, what is physically happening to change a circuit to a “high voltage state” or a “low voltage state”?  This is presumably the lowest level instruction set that exists within computers...and I’m not quite sure I understand how it is being implemented. What is making the circuit change between high and low voltage states...and, moreover, how are these instructions designed to ENACT such a change in voltage state actually being carried out?   This is like the “instruction set that proceeds all other instruction sets”...or the “instruction set that exists BEFORE binary instruction sets can even be formed”. How does one program a circuit to do something before a programming language even exists?  In other words: How does a computer chip convert the "text" or bits that make up the program into action? How does it read the code, decide what the code is saying, and then act on what the code is saying?


In 2014 has any SEO value rewriting urls?  If my site consistently links product page, and that product page shows a consistent canonical url, is there a real SEO doing this  http://example.com/products/woman-tracksuit-in-hemp   instead of this  http://example.com/product.php?id=6588   I know that a human being would be more comfortable with a rewrited url, but I would like to focus on SEO and bots, especially Google


Slow Boot Time on Ubuntu 17.10.1 (systemd-analyze blame results)

I'm very new to Ubuntu.  My PC has had very slow boot and shut down times (for 2 days), I reduced the shut down time with this tutorial () but PC still has some latency problem.  Using systemd-analyze blame from the terminal shows:   17.990s NetworkManager-wait-online.service  7.379s dev-sda1.device  5.271s dev-loop0.device  5.268s dev-loop1.device  5.264s dev-loop2.device  4.067s snapd.service  2.015s postfix@-.service  1.909s plymouth-quit-wait.service  1.467s udisks2.service  1.291s fwupd.service  1.248s networking.service   536ms accounts-daemon.service   447ms tlp.service   433ms ModemManager.service   407ms NetworkManager.service   357ms lm-sensors.service   349ms keyboard-setup.service   339ms preload.service   339ms apparmor.service   333ms grub-common.service   333ms mono-xsp4.service   312ms systemd-logind.service   304ms apport.service   I think there is a problem but I don't know how to fix it.


I was trying to follow this  but I can't get it.  My data comes from this JSON: The green boxes show the values arrays and objets that I need to use.    So I need to find the object inside the array "options" which has the id == 233 and then return it's "value", I'm trying to do it with this function:  function getReqVal(val) {         for (var item in datos_puros[0].campos[0].campos[0].options) {             if(item.id == val) {                return item.value;             }         }     }   I'm bringin the val like this:  getReqVal(datos_puros[0].campos[0].campos[0].value[0]) //console.log(datos_puros[0].campos[0].campos[0].value[0]) --> 233, it works   (datos_puros comes from an previous ajax call)  datos_puros = obj.estructura;   but I can't see where's my error. Please help  This is was I'm trying to do:


I would like to use the flat textures on TextureMate in Blender but am not sure how to convert to 3D textures or even if this is possible. Are there any detailed guides on how to do this? I also have CrazyBump but am not familiar with it yet though this should help hopefully with converting those flat images to normal/bump maps.


xml sitemap: insert node based on a term reference value

I need to create a sitemap.xml to search engine submission. I know (and use) xml sitemap, but I need that the node is insert in the sitemap only if a field term reference has a specified value. Is there any hook_* that I can use in a custom module ?


Can we detect a gravitation field of an object after it failed into a black hole?  Take a simple non-rotating, non-charged black hole and throw a massive object into the black hole:  When the object is outside of the black hole, we can detect the gravitation field of the object.  After the object quickly crossed the event horizon, can we still detect the object's gravitation field?  If yes, does it mean that we (outside of the black hole) can detect how the object fails to the singularity?  If no, how it will look like? Will it be a wave on the event horizon like circular waves on the water? Can we deduce from this wave any information about the state of the object behind the horizon?


Is there a way that when you cycle through the last Space, it cycles you back to the first one?  And, if you cycle backwards and get to the first space, have it cycle back to the last?  Right now, it stops as at the end and beginning, and I'd love to just keep on swiping to cycle.


When android phone (4.3) warns about  Storage space running out. Some system function may not work.  Besides install apps, what can I do to mitigate the problem? I have replaced SD card from 2GB to 32GB. But it doesn't seem to solve problem. Why? Thanks.


How can I make an actual heart symbol in a text on my htc inspire?

I've recieved text message where the the heart wasn't <3 but an actual heart symbol and I have an HTC inspire, how do I send one like that?


The output from the following script \documentclass{article} \usepackage{tikz} \usepackage{graphicx} \begin{document} \begin{tikzpicture}   \node(title)[text width = 0.25\textwidth, text height = 3 cm, draw]{title};   \end{tikzpicture} \end{document}  is  How can I vertically align the text in the node? Specifying the text depth as in \node(title)[text width = 0.25\textwidth, text height = 1cm, text depth = 1 cm, draw]{     title line 1\\     title line 2\\     title line 3};  Does not result in the text being vertically centred.


High pitched beep in house every 15 minutes

Can anyone help? I keep hearing a 3 second high pitched beep but can't quite tell where it is coming from n our lounge where our home theatre system is, i.e. LED TV, receiver, speakers, blu ray player, modulator, router, Foxtel box and modem. There are a couple of cable connector boxes behind the system also. I thought it was our fire detectors but I took out the batteries and I could still hear this beep lasting about 3 seconds every 15 minutes. I unplugged the power for the TV and waited 15 minutes - I could still hear the beep. I unplugged the router - still could hear the beep. I unplugged the Foxtel box - still could hear the beep. I unplugged the receiver - still heard this annoying beep.  Any ideas? Thanks John in Canberra, Australia


Why can we always drop any constant term in a Lagrangian density in quantum field theory?  This issue is somehow related to the constant term being some kind of cosmological constant.  Can you please explain this issue?


Finding the Public IP address in a shell script

I can find my IP address using ifconfig or hostname -i command.  But how do I find my Public IP?  (I have a static public IP but I want to find it out using unix command)


21.5 inch retina iMac used as external monitor

I am thinking of purchasing this little fella  and (also) using it as an external monitor to my MacBook Pro (mid 2014).   Is it possible?


Derogatory word or idiom for city dwellers or people who aren't adapted to country/rural life

I'm looking for something people from rural area would use, especially when they refer to that person's inability to adapt to the country life.


The often told cause of conductor conducting electricity is their valence band and conduction band overlap and when an electric field is applied the electrons jumps into conduction band and electricity flows.I don' t get this how the jump of electrons from valence band to conduction band i.e,the next available energy band cause current to flow.I learnt electrodynamics using free electron sea model and now I am unable to harmonise the two.For example, Suppose we have sodium crystal which is a conductor.The valence band in this case will be the one due to 3s and conduction band  3p.How can a jump from 3s to 3p cause current flow?


What are the necessary conditions for an action to be regarded as a free choice?

A common philosophical question revolves around the existence of free will, but what I've found is that these debates seem to gloss over the concept of "free will" itself, either taking it as a given that everyone understands what the term really means, or proceeding with a very murky and unspecific definition.  So my question is, have there been any attempts to provide a rigorous, mathematical definition of what specific conditions would constitute a free choice? Or, more succinctly, what are the necessary conditions for an action to be regarded as a free choice, rather than a determined one?  This doesn't even have to be confined to a particular world. I would be glad to look at any kind of formalized explanation, in any kind of world (where the laws of "physics" can be totally different from the ones in our world, for example), where one could point to a process which would constitute a free choice.  As a comparison, I could present a mathematical explanation of a deterministic at will. For example,  constitutes a world where any process (that is, where a change occurs) you can point to is a deterministic process.  Now, what change would I have to do to be able to point to a process and say that it was a free process?  When these processes are involved in a choice, the choice inherits the process name. For example: if a brain makes a choice, and the brain is contained within a deterministic universe, such as Conway's Game of Life, the choice becomes deterministic. How could one constitute a universe so the processes behind the choice were constituted in such a way that the choice would become free?  The reason for me asking is that I always find myself dissatisfied with the definitions of "free will" I get, just as I never can wrap my head around the concept of objective values. It's just something you're supposed to intuitively have a concept of and if you don't, you seem to be on your own.  If I speak to somebody who doesn't know what "deterministic" means, I can give a precise, clear, mathematical definition. Since the free will-claim is on a direct collision course with determinism, all I want is for someone in the free will-camp to return the favor. So far, this hasn't happen and since I can't begin to understand what "free will" would be, I haven't been able to produce anything myself.  I'm not asking how one could look at the outcome of a system and decide whether it was generated by free choice or not. I'm also not looking for a proof of free will. I'm simply asking for a way that it could be implemented in some possible world, regardless of whether that is actually the case. We can do this in regard to determinism, for example, without also saying that the world works deterministically (e.g the statement "if every state of the world is fully determined by the previous state, the world is deterministic" doesn't imply that the world also works deterministically).   To better 'illustrate' my point (with the help of Sidney Harris):


I have blender 2.69 and I've been following a tutorial on how to make text.  The only problem is when I go to add a glossy shader in the node editor it does not exist. Neither does the shader category.


Debian package containing combined systemd service and associated executed binary

I've been following the excellent guides to create debian packages to install an application executable    and using dh-systemd to install a systemd service    however, I would like to combine the two to create a package to install a service and install the binary which gets run by the service.  The first tutorial has the application files in the directory above the /debian folder and a make file to build and install the application, whereas the systemd tutorial has the service file in the debian folder. It is not clear to me how to create a control file which installs both service file and dependant binary.  I'd be grateful if someone could advise how to do this or provide some useful reference material.  I've tried reading  but this doesn't explain much.  Is this a realistic expectation, or should services and applications be packaged separately?  Thanks


How to initialize a List to a given size (as opposed to capacity)?

.NET offers a generic list container whose performance is almost identical (see Performance of Arrays vs. Lists question). However they are quite different in initialization.   Arrays are very easy to initialize with a default value, and by definition they already have certain size:  string[] Ar = new string[10];   Which allows one to safely assign random items, say:  Ar[5]="hello";   with list things are more tricky. I can see two ways of doing the same initialization, neither of which is what you would call elegant:  List<string> L = new List<string>(10); for (int i=0;i<10;i++) L.Add(null);   or  string[] Ar = new string[10]; List<string> L = new List<string>(Ar);   What would be a cleaner way?  EDIT: The answers so far refer to capacity, which is something else than pre-populating a list. For example, on a list just created with a capacity of 10, one cannot do L[2]="somevalue"  EDIT 2: People wonder why I want to use lists this way, as it is not the way they are intended to be used. I can see two reasons:   One could quite convincingly argue that lists are the "next generation" arrays, adding flexibility with almost no penalty. Therefore one should use them by default. I'm pointing out they might not be as easy to initialize. What I'm currently writing is a base class offering default functionality as part of a bigger framework. In the default functionality I offer, the size of the List is known in advanced and therefore I could have used an array. However, I want to offer any base class the chance to dynamically extend it and therefore I opt for a list.


Why is the application of probability in QM fundamentally different from application of probability in other areas?

Why is the application of probability in  (QM) fundamentally different from its application in other areas? QM applies probability according to the same  as in other areas of physics, engineering, etc.  Why is there a difference?  Naively one would assume one of these possibilities:   It is not the same probability (theory?) It is a matter of interpretation (of the formalism?) Something else?   Many answers (which I am still studying) focus on the fact that the combined probability of two mutually-exclusive events in QM is not equal to the sum of the probabilities of each event (which holds classically by definition). This fact (appears to) makes the formulation of another probability (a quantum one) a necessity.   Yet this again breaks down to assumed independent, if this is not so, the "classic probability" is applicable (as indeed in other areas). This is one of the main points of the question.


What should I use for filler/placeholder text?

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum?   I tend to think that the classic "Lorem ipsum" text needs explaining to clients who haven't seen it before. But text along the lines of the following seem inelegant:     Copy goes here. Copy goes here. Copy goes here.   Xxxxxx xx x xxx. Xxxxxxxx xx xxx x xx   Are there any alternatives I should consider?


Is there a standard way to include ORCID in TeX / PDF?

I would like to add the ORCID to the metadata of documents I write. Is this possible with PDF? Is there a standard way to include it in TeX?  The nicest way would be if there way a standard TeX command so that the compiled PDF would automatically have this information. But if it is possible to add this after the PDF was compiled, it would be nice, too.  The simplest way to add the ORCID to the TeX code is adding a comment  % ORCID of the author: http://orcid.org/0000-0002-6517-1690   But how do other people add their ORCID to papers? Is there a recommendation how to do it, so that scripts / search engines can use the information?


I am trying to make my sections small caps. I have tried:  \documentclass{article}  \usepackage{lmodern}  \begin{document} \section*{\textsc{Test}} \end{document}   But this complains that no bold small caps font exists. How can I unbold the sections and as a bonus automatically make them small caps? I tried looking at titlesec but I found it quite confusing as I am a beginner.


Is this a suitable sine wave osc? how would I control the frequency?

Overview-  I'm making a bank of analog sine wave oscillators and I'm interested in keeping the design compact.  I've started by making a Wien Bridge oscillator. As I'm working from a single power supply and I'm trying to keep the design small, I've been using the LM386n-1 IC.  I'll be using the oscillators to do some additive audio synthesis, maybe some FM and I'll probably need some of the oscillators as LFOs.  My questions are-  Is this a suitable approach for making a compact analog sine wave oscillator?  Also, how would you suggest I control the frequency, which component value should be changed to achieve this? - I've tried messing with all the resistors to change the pitch, but they all seem to be interdependent.  Here is the circuit I've been working from, it's from the National Semiconductor LM386 Low Voltage Audio Power Amplifier datasheet-    And this is what my implementation looks like, I don't have a suitable incandescent bulb so I've just replaced it with a 1KΩ pot. I'm still not sure what I'll use in the final circuit as AGC, suggestions are welcome.


If there is no ether what is the medium in which waves, pulses travel around the universe?

What is aether (ether) actually? Is it space-time fabric curve or is it anti-matter? If not this what is it then, does it exist? Why is the concept disregarded after Einstein's theory of Relativity? But Ether experimentally satisfies maxwell's equation and is it due to ether we define relative permitivity?


Assume that you are holding a cage containing a bird.  Do you have to make less effort if the bird flies from its position in the cage and manages to stay in the middle without touching the walls of the cage? Does it make a difference whether the cage is completely closed or it has rods to let air pass?


Is there any decent speech recognition software for Linux?

The short version of the question: I am looking for a speech recognition software that runs on Linux and has decent accuracy and usability. Any license and price is fine. It should not be restricted to voice commands, as I want to be able to dictate text.  More details: I have unsatisfyingly tried the following:       (e.g., )  (used to run  on Linux but was discontinued years ago)      (built on the Kaldi speech recognition toolkit)    +  +  +   : only accepts voice commands  All the above-mentioned native Linux solutions have both poor accuracy and usability (or some don't allow free-text dictation but only voice commands). By poor accuracy, I mean an accuracy significantly below the one the speech recognition software I mentioned below for other platforms have. As for Wine + Dragon NaturallySpeaking, in my experience it keeps crashing, and I don't seem to be the only one to have such issues unfortunately. On Microsoft Windows I use Dragon NaturallySpeaking, on Apple Mac OS X I use Apple Dictation and DragonDictate, on Android I use Google speech recognition, and on iOS I use the built-in Apple speech recognition. Baidu Research released  the  for its speech recognition library using  implemented with Torch. Benchmarks from  are encouraging as shown in the table below, but I am not aware of any good wrapper around to make it usable without quite some coding (and a large training data set):      System Clean (94) Noisy (82) Combined (176)     Apple Dictation 14.24 43.76 26.73   Bing Speech 11.73 36.12 22.05   Google API 6.64 30.47 16.72   wit.ai 7.94 35.06 19.41   Deep Speech 6.56 19.06 11.85     Table 4: Results (%WER) for 3 systems evaluated on the original audio. All systems are scored only on the utterances with predictions given by all systems. The number in the parentheses next to each dataset, e.g. Clean (94), is the number of utterances scored.  There exist some very alpha open-source projects:   (part of Mozilla's Vaani project:   ())  Vox, a system to control a Linux system using Dragon NaturallySpeaking:  +     (to be released by Google, mentioned at Interspeech 2018)  I am also aware of this  as well as this .  I am aware of  , which allows speech recognition via Dragonfly on one computer to send events to another, but it has some latency cost:  I am also aware of these two talks exploring Linux option for speech recognition:   (David Williams-King)  (Tavis Rudd)


I've been trying to learn about the speed of light and time dilation, but I'm at an impasse.  The presented facts say that if I travel around the solar system at 50% the speed of light and then come back to earth I will have experienced less local passage of time than them. I will effectively have traveled to their future. I've also read that gravity causes time dilation too.  I understand that space-time is a sort of unified thing and that affecting space affects time. It makes sense then that gravitational forces bending space will also bend time. But velocity? I can't wrap my head around it and I can't find a good explanation for it.  People cite orbiting craft and planes as proof of time dilation, since their clocks will go slower than those in the surface (and vice-versa). This certainly explains gravitational time-dilation, but not necessarily velocity. Can't the change in local time passage be caused solely by the gravitational bending of space-time?   Trying to find an answer, I came to a very recurring and frustrating example in texts that seek to explain time dilation. A man on a moving train throws a ball forward. Since he's moving with the train and the train is his point of reference, the ball to him only moves at the speed he threw it. But to a woman on the station the ball is moving at the speed of the train plus the speed it was thrown with. To some authors, this seems to open the mind to time-dilation understanding. To me it only explains the relative nature of motion. It says nothing of time.  Another example I've found: if person A speeds away from person B very quickly, A's clock will seem to advance slower from B's point of view. How is this time dilation, though? The difference can be explained by the longer time it takes light to get to B, can't it?  I realize I can't be right against the fine physicists out there, so I was hoping someone here could enlighten me. Where does the notion that velocity causes time-dilation come from?


Ubuntu 16.10 Yakketty won't update. Can I fix it, or should I get 16.04, or 17.10?

So I had a beautiful system running real nice up until I wanted to set up an old webcam last night. I did sudo apt-get update and got this:  Fetched 1,475 B in 3min 25s (7 B/s) Reading package lists... Done W: The repository 'http://security.ubuntu.com/ubuntu yakkety-security Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: The repository 'http://ca.archive.ubuntu.com/ubuntu yakkety Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://download.opensuse.org/repositories/home:/jgeboski/xUbuntu_16.10  Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 12C6ADA61C85BB5E W: The repository 'http://download.opensuse.org/repositories/home:/jgeboski/xUbuntu_16.10  Release' is not signed. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: The repository 'http://ca.archive.ubuntu.com/ubuntu yakkety-updates Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: The repository 'http://ca.archive.ubuntu.com/ubuntu yakkety-backports Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: The repository 'http://ppa.launchpad.net/eugenesan/ppa/ubuntu yakkety Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.   And sudo apt-get install for anything yields  E: Package 'program' has no installation candidate   I suspect that I'm having this issue because I'm using Ubuntu 16.10. If not, I'd like to know how to fix it, because I really like my system the way it is. Otherwise, I'd consider installing 16.04 or 17.10, but I'd also like to know  which one is better, and if there is a way to install without losing all my programs and stuff. Some of them were pretty frustrating to install, and I really need them.  Thanks!


Seeking shapefile for postal codes/zip codes of India?

I have been searching for free/paid (preferably free) sources for postal code shapefiles for India.   Does anyone know where I can find one?


How much swap memory should i have if i have 2 GB of ram?

I'll be basically doing programming and stuff.


Prevent scanning of the Apache's /default directory

I have two directories, under /var/www/vhosts: mydomain/ and default/. Files in default directory can be accessed using IP address of our server.   I have checked Apache log and somebody is constantly, trying to access random files under that directory - is performing "mapping". Also IP address, from which request is coming appears always different in Apache's error log. I have also a suspicion that this mapping causes Apache to run out of available slots, and jam at the end.  Here is a snippet from Apache log:  [Mon May 14 16:04:04 2012] [error] [client 190.12.83.230] File does not exist: /var/www/vhosts/default/htdocs/manager [Mon May 14 16:05:29 2012] [error] [client 200.48.7.17] File does not exist: /var/www/vhosts/default/htdocs/manager [Mon May 14 16:19:12 2012] [error] server reached MaxClients setting, consider raising the MaxClients setting   Is there any way to prevent these attacks?


Finding formula of all solution of a point P, where two tangent line to an ellipse from P is perpendicular to each other

the only information given is ellipse equation x^2/17+y^2/8=1, first I tried to substitute y in ellipse equation with m(x-a)+b, then I tried to make determinant zero, getting 2nd order equation of am^2+bm+c=0, then I tried to get the determinant of this equation higher than zero, noting c/a= m1.m2 and m1.m2=-1, but I don't know the rest.


Remove user restrictions privilege "earned" at 101 rep with association bonus only?

I know that as a new user(or one with only the association bonus like me), one cannot post answers to protected questions, like :  However, I noticed something very strange. When I click on the link that leads me to the "Remove New User Restrictions" page, on the side, it shows that I have earned the privilege on this site, which I have clearly not, being at 101 rep with the association bonus:  Question: is this a bug that needs to be fixed?


How can a singularity have infinite density?

I've heard many times that black holes have infinite density at their center, but I've also heard astronomers quote mass estimates for black holes. How could the singularity have infinite density if it has a finite mass?  EDIT: Also, if the singularity has a size above zero, what is it?


How do I create a copy of an object in PHP?

It appears that in PHP objects are passed by reference. Even assignment operators do not appear to be creating a copy of the Object.  Here's a simple, contrived proof:  <?php  class A {     public $b; }   function set_b($obj) { $obj->b = "after"; }  $a = new A(); $a->b = "before"; $c = $a; //i would especially expect this to create a copy.  set_b($a);  print $a->b; //i would expect this to show 'before' print $c->b; //i would ESPECIALLY expect this to show 'before'  ?>   In both print cases I am getting 'after'  So, how do I pass $a to set_b() by value, not by reference?


Why does CBC decryption with a wrong IV still give readable results?

While developing some code that uses the .NET AesManaged algorithm, I made some mistakes but was surprised at the results.  My encryption was correct.  I was generating a random IV block and writing it to the file (without encrypting the IV).  Then I was encrypting the plaintext and writing it.  The decryption was wrong though... instead of reading the first block from the file an using it as an IV, it was just using a random IV and decrypting everything.  The first block came out gibberish but the 2nd (and subsequent) ones were decrypted properly!  Why would this be?  And even weirder... when I tried to fix it by encrypting the IV in the encryption code (instead of writing the IV unchanged) the decryption result was the same!  (gibberish then correctly decrypted blocks).  Although I eventually fixed my code, how do these results make sense?


Unique constraint to enforce max one null per item

I am using PostgreSQL 9.3. Suppose we are manufacturing some items of certain types, at any moment we are producing at most one item of a certain type. The following table captures our history of manufactured items, there may be rows where manufactured_until is null - those are the items produced currently.  create table item (   id int,   type_id int,   manufactured_from timestamp,   manufactured_until timestamp )   Sample data:  1  | 101  | 1.1.2000    | 31.12.2012 2  | 102  | 1.4.2003    | 1.1.2010 3  | 101  | 1.1.2013    |  4  | 102  | 2.1.2010    | 4.5.2014 5  | 102  | 5.5.2014    |    The following logic should hold: for each item type, there should be at most one item being produced at the moment (manufactured IS NULL). In the example, I should not be able to add the record (6, 101, 27.8.2014, NULL).   I'd like to write a UNIQUE constraint that will guard this. Is it possible? For bonus points, is there a reasonably complex way to guard that the intervals do not overlap for one item type?


Convergence of $\sum_{n=1}^\infty \frac{\sqrt[n]{n} - 1}{n}$

I am looking for the convergence of $$\sum_{n=1}^\infty \frac{\sqrt[n]{n} - 1}n$$  I have tried ratio test/ root test and tried to compare with other convergent series but I do not get anywhere. Also, limit comparison of $a_n$ didn't seems to work.


How do you review mass tag edits by one user?

I've seen this a few times now but so far I skipped such suggested edits, because I'm unsure what to do.  Right now in the "Suggested Edits" queue, there are a bunch of questions where the tags  and  are replaced by . These are all suggested by the same user.  Assuming that the questions themselves don't require improvements, how should I review these suggested edits?


I have been looking around for an easy way to convert 12V to 5V. I have seen some people saying that a simple resistor is all that is needed.  $$ Volts = Ohms \cdot Amps $$ $$ Amps  = \frac{Volts}{Ohms} $$ $$Ohms  = \frac{Volts}{Amps}$$  So applying a resistor will diminish the voltage of the circuit. That should mean that an appropriately sized resistor could simply be placed in the path of a 12V circuit, converting it to 5v.   If this is the case how would one reduce amps? Would series vs parallel make a difference in this area?   I have seen designs that include a regulator IC and some capacitors, but if a simple resistor/fuse/diode setup will do the trick, I would really prefer that.


Why does the .NET framework rely on interfaces?

I am working on learning C# in depth. I am mostly confused by the frequent implementation of interfaces. I always read that this class implements this interface. For instance, SqlConnection class implements IDbConnection. What is the benefit for developers in this case?


Why are not all Stack Exchange sites available for migrating off-topic question?

I encountered today the following question:     Because it should be asked in Math.SE site. I voted to close it. You can select it should be posted into one of five other forums, but  is not possible to select. Why are not all Stack Exchange sites available?


Per the answers  I'm able to list the contents of my tarball in ls format. However, I'd like to be able to list them in tree format, i.e. something like the latter instead of the former:  With tar:  $ tar -tf foo.tar  foo/ foo/baz/ foo/baz/qux/ foo/baz/qux/hisfile.txt foo/bar/ foo/bar/myfile.txt foo/bar/yourfile.txt   With tree:  $ tree foo foo ├── bar │   ├── myfile.txt │   └── yourfile.txt └── baz     └── qux         └── hisfile.txt   Is it possible to do this without extracting the tarball? I'd prefer to have to avoid extracting the tarball due to their size.


Is the work-done by a magnetic field on a moving point charge zero?

Blue vector is the magnetic field vector. Red vector is the velocity vector of the point charge (light grey) q. Green vector is the force vector (force on moving charge q due to the magnetic field). I have heard that workdone by a magnetic field on a moving charge is zero. Let's say that a charge q which was already moving with a velocity 'V' came under the influence of a magnetic field 'B'. It started experiencing a force 'F' due to the magnetic field given by F = q(V vector X B vector). Now due to this it will also start moving along the 'y' axis with some acceleration. So wouldn't we say that the work-done = F x displacement in y ?  Edit: What I am trying to say is that the displacement of the charge will have a 'y' component and the force here is also acting in the 'y' direction', so shouldn't the expression I wrote above be valid?


Count the number of occurences of every group of numbers in a line

I now understand that a similar question has been asked, but not everyone might come to the adapted solution for this version of the question straight away.  Is there a simple way to count the number of occurrences of every group of numbers in a string? I can't think of one and anything I can think of seems way too convoluted, for what seems like a simple ish task.  (note that any string of numbers in the line could be any length)  Example input:  AGTHDTGY35AHSJFHHFG7GHHAHH   Example output:  2


How to automate PDF processing (crop & reduce size) without breaking barcode?

I regularly receive shipping address labels in pdf format from the post. The pdf document containing the address label is formatted in a very stupid way taking up the entire A4, while just A6 would be enough. One has to cut about 70% of the page and throw the excess paper to trash, to get the address label. Then one has to use a glue stick to glue it on the shipment.  The label contains the recipient's address details, sender's details, and postage & tracking information, both as a barcode.  I would rather use standard self-adhesive sticker labels and a label printer instead. To achieve this, I would need to process each pdf file to crop out the label, shrink parts (the boxed fields) of the label slightly to fit it to the A6 shipping label size.  The cropped label needs to be downscaled to A6 size. But how to prevent the barcode from getting broken? Pdfposter breaks the parcel tracking barcode.