Today in the middle of my ride it started raining and I could barely see due to the amount of rain on my glasses.  This is basically what I could see   I have jokingly talked about using Rain-X on my glasses, but now it's starting to seem like a good idea.  Is there a way to keep this from happening or at least to a minimum?


Why do no particles have a 1/3 spin? Why are all particles' spin either a half-integer or integer? How would a particle with such a spin behave, as a fermion, boson, or neither?


I'm a little bored of Windows 10 and as of yesterday I could no longer access my desktop so it was time to change! Does anyone has any experience with getting a Dual boot with windows 10 / installing Linux with windows 10 in general? If so, is there any articular settings etc. that needs changing in order for it to run smoothly?  Thanks,  Z


When exiting views modal I am returned json

When I am in views UI and I edit an option a modal box appears. I edit some seetings then press save and am displayed with something like:     [{"command":"settings","settings":{"basePath":"/","pathPrefix":"","ajaxPageState":{"theme":"bartik","theme_token":"SUIsCUisas2D3yeSiBkGNwaXtTMtlVVXouHWgoffCYA"}},"merge":true},{"command":"viewsDismissForm"},{"command":"viewsShowButtons"},{"command":"viewsTriggerPreview"},{"command":"insert","method":"html","selector":"#views-tab-block","data":"\u003Cdiv   id=\u0022edit-display-settings-details\u0022\u003E\u003Cdiv   id=\u0022edit-display-settings-top\u0022   class=\u0022views-ui-display-tab-actions views-ui-display-tab-bucket   clearfix\u0022\u003E\u003Cdiv class=\u0022ctools-no-js ctools-button   ctools-dropbutton\u0022\u003E\u003Cdiv   class=\u0022ctools-link\u0022\u003E\u003Ca href=\u0022#\u0022   class=\u0022ctools-twisty   ctools-text\u0022\u003Eopen\u003C/a\u003E\u003C/div\u003E\u003Cdiv   class=\u0022ctools-content\u0022\u003E\u003Cul class=\u0022horizontal   right actions\u0022\u003E\u003Cli class=\u0022duplicate ...   What could be going wrong?


What exactly is threshold for answering protected questions?

This is said in      Privileges not tied to a specific threshold         To answer protected questions, you need to gain 10 reputation on the site – the association bonus does not count. In other words, the reputation threshold for answering protected questions if you have the bonus is 110, not 10.      If my Maths and English aren't too bad, gained 10 = 1 + 10 = 11 (or 111 with assoc-bonus). But it says 110, as well as a lot of other places:   Another FAQ:      Who can answer a protected question?      Users with 10 or more reputation can answer a protected question. However, the +100 account association bonus is ignored for this check.       In practice the check is all bodged up and inconsistent. In particular, if you associate an account and get no bonus (cause you have less than 200 rep) we arbitrarily decide that you need 111 rep to post answers.    Those conflicts are really embrangling. Question:  Is it 10/110 or 11/111 (new user / user with assoc bonus)?


Linux network troubleshooting and debugging

From time to time Linux and Unix users faced with various network problems. Many of these problems are presented here and at some others troubleshooting forums, but they are very concrete and contains a lot of additional technical information, and sometimes it's rather difficult to understand the main point and the real reason of buggy system behavior.   By asking this question, my intention is to start a community wiki page which allows generalizing our network troubleshooting and debugging experience. I hope the Linux and Unix users could easier recognize and solve("divide and conquer") their network problems using this page.   The parent of this page should be  . But here we should focus on troubleshooting the network problems from user- and kernel-space.  I suppose, if you:    Share the information about using some great network diagnostic tool with concrete usage examples and examples of network bugs, which they help to catch. Share the link to the great network tutorial connected with this subject Tell about a general method or recipe which allows to tackle some class of network problems Share information about your tool-set for network debugging and troubleshooting   it would perfectly fits for this topic.    I'll begin from sharing the link to varios  and . Also  seem to have actual information about our subject. And for diving into linux networking we definetely need to visit .


Why would you want to use a digital envelope? As I understand it, a plain-text message is encrypted using a secret key and then the key is encrypted with the receiver's public key. The encrypted message and the encrypted key is sent as the digital envelope. Now, what I don't understand is why one just don't encrypt the plain-text message with the public key in the first place? The literature I have been reading states that the secret key used to encrypt the message is a one-time key, so wouldn't this render the digital envelope unnecessary? I would understand the purpose of a digital envelope if it was to encrypt the secret key for continued communication, but according to the literature, this does not seem to be the case.


How to store a weak reference to an object?

I want to store a weak reference to an object in Javascript. I'm trying to implement a cache, and to avoid memory leaks I don't want to hold any strong references. I would use WeakMap or WeakSet, but those do not allow me to retrieve objects after they are inserted, defeating the purpose of a cache.  Is there any way to implement a "normal" weak reference in Javascript? Is there a work around I could use in my cache to avoid leaking memory?  Edit: See the duplicate question.  I ended up just using normal references and periodically emptying the cache to deal with memory leaks. Not a great solution, but that's Javascript for you...


Extracting chmod file permissions in PHP

I come with a problem. Well, I wanted to make notifications about too high chmod file. Here is the code I wrote:  <?php defined('BASEPATH') OR exit('No direct script access allowed!'); $errors = FALSE; $config_file = "config.php";  if(is_writeable(APPPATH.'config/'.$config_file)) {     $errors = TRUE;      $_SESSION['chmod_error'] = "
 Configuration file (".$config_file.") is writeable!
"; } else {     $_SESSION['chmod_error'] = "
 Configuration file (".$config_file.") is not writeable
"; }   Unfortunately, it does not work properly. It still displays the same error even if the chmods are set to 777 or 644.  Photo here:   Is there a way to "get" what chmod file has? And can you show an error if the file has a higher chmod than eg 644? If so, how do you do it?  Thank you in advance for your help and sorry, but my English is not perfect, so I have to help myself Google Translate :D


Proving equalities with sets: $A \cap (B \cup C) = (A \cap B) \cup (A \cap C)$ and $X \setminus (A \cap B) = (X \setminus A) \cup (X \setminus B)$

We got this exercise sheet and I don't really know how to solve some of the problems, thanks for any help or/and advice!  Problem a) $A,B$ and $C$ are sets. Prove that:   $A \cap (B \cup C) = (A \cap B) \cup (A \cap C)$   Problem b) Proof that for sets $A, B\subset X$ counts   $X \setminus (A \cap B) = (X \setminus A) \cup (X \setminus B)$   If someone could explain how I'm supposed to write down the proof I will probably be able to solve the rest on my own, all I need is a little start help.  Thanks a lot!


Applying password with command in Terminal

Is there an option to apply a password with the command in the terminal? Somethhing like:  sudo some-command -pass=mypass   I'm just curious, I know that this is not safe.


I have a large dataset of tennis-points (who served and if they won etc).  Now I would like to check if the points have any correlation with each other (does winning/losing the previous point affect the current or the one after this?).  I also have an "estimate" of each players serve-winning probability as well as his "actual" serve-winning probability in the game (calculated from the dataset).  Ive tried looking into autocorrelation but I honestly dont know where to start. Does anyone have any idea how to test if Point X have any effect on the outcome of Point X+1?  Any help is greatly appreciated  PS. I tried asking a similar question describing how I thought and the only answer I get was "You are lacking fundamental understanding about probability-theory", hence this time I havent included any of my own thought-process, but feel free to ask for more info if I have excluded something important DS.


$\textbf{Problem}$ $K=\mathbb{Z}/p\mathbb{Z}$; L=splitting field of $\prod_{i=1}^{p-1} (t^2-i)$, where $p$ is an odd prime $\textbf{Attempt}$ Since $(-k)^2=(p-k)^2=k^2$, we know that there are $\frac{p-1}{2}$ many irreducible polynomials among $t^2-1,t^2-2,\cdots,t^2-(p-1)$. This implies that among $1,2,\cdots,p-1$, $\frac{p-1}{2}$ are squares and other $\frac{p-1}{2}$ are not.  Then, the splitting field of the polynomial be $K(\sqrt{k_1},\cdots,\sqrt{k_{\frac{p-1}{2}}})$... I don't know how to compute the Galois group... Any help is appreciated.. Thank you!


comparing the first column of two files and printing the entire row of the second file if the first columns match

I have two files in these formats:   file1 :  air smell hand dude road cat   file 2:   air,4,21,01,13,3,2 smell,21,4,2,5,6 dude,1,31,42,1 road,1,4,2,1,4 cat,1,5,6,3,1 hand,1,4,2,1,6 mouse,1,3,5,6,2   what I want to do is print the entire row of file 2, if the first string in column 1 of file 2 is found in file 1, and I want to keep the order of file 1.   expected output:   air,4,21,01,13,3,2 smell,21,4,2,5,6 hand,1,4,2,1,6 dude,1,31,42,1 road,1,4,2,1,4 cat,1,5,6,3,1


Is there any way to exclude certain Stack Exchange sites from the hot list?

I would like to prevent one site in particular from showing up in my hot network question list.  Is there any way to do that?


How is subjective experience of color mapped to the visible spectrum?

Kevin Warwick had a  and could sense whether an object was close or far. Evidence is accumulating that our brains can make sense of "foreign" information like sonar (consider the vOICe).  It can be assumed/hoped that artificial eyes will feed the human brain information more than the currently available spectrum (into the visual sense, not through the sense of warmth).   Infrared via carotine diet  There  to extend the human spectrum into the realm of infrared by maintaining a , but they were abandoned) when technological advances made seeing infrared easier.  Ultraviolet in aphakic patients - edited in  Some people with cataracts have their lense removed (resulting in aphakia),  leading to UV vision.     The eye represents a compromise between clear focus and breadth of spectrum. What does ultraviolet look like? Prof Stark possesses UV vision because he is aphakic in one eye and, with Professor Karel Tan, has published research on the nearest visible equivalent. His conclusion is that it looks whitish blue or, for some wavelengths, a whitish violet.   Thought experiment  A thought experiment with an extended visible spectrum seems interesting to me. It touches both on the qualia debate and cognitive science. I still hope you won't vote this off-topic, because I don't think cognitive science has the answer concerning the subjective experience of the stretched spectrum.  I can think of two main possibilities.  for reference the current (most common) human visible spectrum with wavelengths as objective baseline (from Wikimedia)    1. Our current repertoire of colors is stretched.    2. We see new colors.    Has this been debated in the literature? What is being proposed? Are (1) and (2) actually the same (more acuity = more colors)?  I think there is no expectation implicit in language (infrared and ultraviolet), but still when people want to demonstrate heat vision they often use red color and, um, well I don't know any movies about superheros with bee vision.


Using the Catapult spell with a flask of alchemist's fire, can you deliver both 3d8 bludgeoning damage as well as the alchemist's fire damage?

Using the  spell with a flask of , can you deliver both 3d8 bludgeoning damage as well as the alchemist's fire damage?


What are the differences between @class method, @static method, and a normal function and how do I use them

I'm trying to get into Object-Oriented Programming for Python, but I definitely don't have the Programming literacy to understand any guides out there. I would be grateful if anyone could help me understand how to use and clarify the differences between "normal functions", "@class method", and "@static method" in a way that a beginner like me could understand.   A guide that I had no clue how to use, .


Question about fields and quotients of polynomial rings

I don't see how to solve the following problem:     Let $R$ be a commutative and unitary ring. If there exists a monic polynomial $f(x) \in R[x]$ so that $R[x]/(f(x))$ is a field, show that $R$ is a field. What about if $f(x)$ isn't monic?   I don't have a clue about how proving it. I see that if $R$ is a field and $f(x)$ a monic and irreducible polynomial in $R[X]$ then $\frac{R[x]}{(f(x))}$ is a field, but that is not the question!  Thank you in advance for your help


What is the difference between the following sentences? for me both are same.   you can search it in google & you could search it in google


Does Data have Bluetooth or similar radio?

Every time I see Data interacting with a computer or network he is using a terminal or communicator just like everyone else.  Surely a bluetooth or communicator device could easily be incorporated into his body.  Does he have integrated wireless and just chooses not to use it to appear more human, or is there some other canon reason for not being wireless?  Data at terminal wearing a communicator


I recently got banned from SoftwareEngineering.StackExchange.com. The point of this post is not to get the ban lifted, or to argue with the negative scores of my posts. It is to discuss the ban system and whether or not it could be improved.  The thing is, that even though I recently got the ban, the two posts that (most likely) caused the ban are more than three years old (see the screenshot). According to the guidelines the ban can be lifted by improving the score of negative received posts or simply by waiting six months. Since the posts are so old that no one will ever see them, the only real option is to wait for six months.   So here are my two points:   Could the system be improved so that the ban occurs sooner after the negative received posts. Improving the feedback loop, would (probably) lead to faster reactions improving poor questions, leading to higher quality content. I am aware that this might be a technically difficult thing to implement though. Make the ban period start from the date, where the users latest poor post was submitted, rather than the users latest post (even if that was well received). This would seem like a more "fair" way of doing things, but it would possibly prevent a more poor questions, as the "time-to-think" period would occur immediately after the problematic post(s) and not years later, where the quality of the posts already increased (at least in my case).   And again, I have no hopes or expectations for my own account with this post. It is meant to discuss the system, not me personally.  What do you think?


Compile error IEEE access template using algorithm2e package

I have been trying for a while to load the algorithm2e package to the IEEE ACCESS template. Whenever I use the following code, I am getting the error \usepackage{amsmath,amssymb,amsfonts} % \usepackage{algorithm, algorithmic} \usepackage{graphicx} \usepackage{textcomp}  \usepackage[ruled, linesnumbered]{algorithm2e}   \begin{document}   \IncMargin{1em} \begin{algorithm*}[!t]     \caption{Caption}     \DontPrintSemicolon     \Indm          \KwIn{%             Input 1          }%     \Indp     Statement 1 \;  \end{algorithm*} \DecMargin{1em}   \EOD  \end{document}  Error is Argument of \relsize  has an extra }. <inserted text>                 \par  l.23     S          tatement 1 \; Runaway argument?  If preamble \usepackage[ruled, linesnumbered]{algorithm2e} to \usepackage[ruled]{algorithm2e}, above code works well, but following code doesn't compile with other error messages \documentclass{ieeeaccess} \usepackage{cite} \usepackage{amsmath,amssymb,amsfonts} % \usepackage{algorithm, algorithmic} \usepackage{graphicx} \usepackage{textcomp}  \usepackage[ruled]{algorithm2e}   \begin{document}   \IncMargin{1em} \begin{algorithm*}[!t]     \caption{Caption}     \DontPrintSemicolon     \Indm          \KwIn{%             Input 1          }%     \Indp     Statement 1 \;     \If{$a==1$}{         aaa \;     }  \end{algorithm*} \DecMargin{1em}   \EOD  \end{document}  Error is  Paragraph ended before \@algocf@endoption was complete. <to be read again>                     \par  l.27 \end          {algorithm*}


How does temperature relate to the kinetic energy of molecules?

In ideal gas model,  is the measure of average kinetic energy of the gas molecules. If by some means the gas particles are accelerated to a very high speed in one direction, KE certainly increased, can we say the gas becomes hotter? Do we need to distinguish the random vibration KE and KE in one direction?  Furthermore, if we accelerate a block of metal with ultrasonic vibrator so that the metal is vibrating in very high speed with cyclic motion, can we say the metal is hot when it is moving but suddenly become much cooler when the vibration stop?


Including pdf as appendix without shift of page

When I try to include a pdf file in my appendices, it gives the header and the label, and begins the pdf-file on the next page. I have a lot of pdf-files as my appendices, many only 1 page long, meaning I will have a lot of blank pages only saying:   \usepackage{pdfpages} \begin{appendices} \section{Interviews} \subsection{Interview: Christine} \includepdf[pages=1-2]{fig/interviews/christine.pdf} \end{appendices}   This results in:     The rest of the page is then blank, and the actual appendix begins on the next page.   Is there any way I can alter the pdf-file to begin on the same page as the headline, maybe by scaling it to be smaller than actual page-sizes, so it fits on the same page?


Unexpected Identifier for Onclick Javascript button

I created a custom button for custom object to place in the related list. The custom object has two look-ups, one for case and one for account. This button, when clicked, should open in a new window to save a record of the custom object, with the default values for each look-up to populate automatically depending on the record where the button was clicked. It works for every record so far, except one case. It then throws the error: A problem with the Onclick Javascript for this button or link was encountered: Unexpected identifier.  I couldn't find any differences between records where it works and doesn't.  Code:  window.open('a2U/e?CF00N600000037HI4={!Account.Name}&CF00N600000037HI4_lkid={!Account.Id}&retURL=%2F{!Account.Id}&CF00N600000037HI5={!Case.CaseNumber}&CF00N600000037HI5_lkid={!Case.Id}&retURL=%2F{!Case.Id}','','scrollbars=no,menubar=no,height=600,width=800,resizable=yes,toolbar=yes,location=yes,status=yes');


What possessive is used when "everybody" is the antecedent?

Is this sentence right?     Everybody is wasting his time.   Is  his or its the possessive of everybody?  Most people use his but in my opinion it should be its:      Everybody is wasting its time.   I want to know what experts say about this.


Show the continuous image of a compact set is compact.

Using the open-cover definition of compactness (if X is a topological space, a collection of sets {$U_{\alpha}|\alpha\in A$} with each being open in X, is said to be an open cover of X if $X=\bigcup_{\alpha\in A}U_\alpha$. The space $X$ is compact if for every open cover of $X$, there is a finite subcollection of {$U_\alpha$} that is also an open cover of X.) prove that the continuous image of a compact set is compact. This implies compactness is a topological property? The exercise hints at starting with an arbitrary open cover of the image space. Any further hints would be appreciated. Thanks in advance!   Edit: I believe  concerns a less general case in $R^n$. Also, the answers do not address open covers which is the source of much of my confusion.


I don't know why my reputation decreased

I don't understand why my reputation decreased from 256 to 241.  I even checked on  but it is not showing what I believe to be the correct result.  What might be the problem?


Is there any scripts for downloading and installing IntelliJ with JavaJDK or OpenJDK?  I don't know how I did it before using Ubuntu 12.10 but I'm now on a fresh 13.04 install and I have been looking around for an all in one script, or some scripts I can cobble together  I have the two links detailed that I think will be handy, can anyone else add to this please?      Update: I have now found you can install IntelliJ through the Ubuntu software centre, so although this was a nice learning exercise for me it's not really relevant any more. Thanks to everyone that contributed.


Recently, I have started a project that needs to use stratified two-sample t-test. I know about one sample, independent two sample and paired t-test in R. My guess is that the project asks for ANOVA. How can I do stratified two-sample t-test in R. Thanks.


"Having you feel that way makes me feel hopeless" or Having you feeling that way makes me feel hopeless"?

Which sentence is grammatically correct and WHY?


Is it safe to install Ubuntu on Samsung Laptop from 2013

What do I need to do to install Ubuntu on my Samsung Laptop from 2013? I heard that I can brick it. If I need to do an update then please give me instructions. Sorry for asking such an easy question. I'm a linux noob.


The locus of the intersection point of two perpendicular tangents to a given ellipse

For a given ellipse, find the locus of all points P for which the two tangents are perpendicular.   I have a trigonometric proof that the locus is a circle, but I'd like a pure (synthetic) geometry proof.


Short story: man watches girlfriend's spaceship entering a 'black hole' (?) forever

I read a sci-fi story in a collection of shorts about 10 years ago, I believe they were stories from 70s possibly and have been trying to track down the title.  My recollection is that a number of ships encountered problems with a black hole or similar timey-wimey space object, and the ship belonging to the protagonist's girlfriend/love interest sacrifices itself to save the others. The 'black hole's' properties being what they are, the man goes on to live his life on Earth where the ship is visible in space, stuck in the moment of their sacrifice forever.


What is the most efficient way to lock a specific row for within a mysql transaction. I am currently using for update using select is there another method that im unaware of?  if not are mysql locks only released when committed or rolled back?  for example i run the following transaction: begin select for update insert.. insert.. update(locked table) select another table commit does the commit release the lock or the update?


Running a .sh to execute multiple commands

I was curious how I would go about running multiple commands via shell script.  For example, just to try it out, I'd like to be able to connect a .desktop to a .sh that will run all the update codes so I don't have to type it out. I know how to execute a single command via a .sh, not multiple.  Any way?


I am prominent on a particular exchange where one user has taken it up on themself to post regular posts trying to pick at basic rules on how Stack Exchange works. I have pointed out that it is a Meta Stack Exchange issue, but they insist that thay have to ask it in the per-site Meta, as they do not have enough reputation to ask, here.  I am previously use to having an option to simply invite the user to discuss in a private chatroom away from the meta post, as it is clear his misunderstanding of how Stack Exchange works goes past a couple of comments or more. But I can not find the option.  How do I send an automated link, in chat, to invite the asker to join me in a chat room for further discussion?


Creating an object inside a method vs creating the object outside a method

I saw like in Java there is no pass by reference. But for the below two scenarios, which one is better?  1.  public static void main(String args[]) {     CarDto car = new CarDto();     method1(car);     //do something with car }   private void method1(CarDto car) {     car.setName("BMW"); }   2.  public static void main(String args[]) {     CarDto car = method2();     //do something with car }  private CarDto method2() {       CarDto car = new CarDto();     car.setName("BMW");     return car; }   As per my understanding, method 1 is better than method 2. In method 1, only one CarDto object is created. In method 2, there are two CarDto object created.  Please clarify.


Finding the area of polygons within other polygons in R

Is there a function in R which will loop through a layer of zonal polygons (i.e. a polygon grid) and return the area of a second polygon layer that is contained in each grid cell? I have a layer of polygons representing areas of forest (in blue), and a second layer representing ordinance survey grid cells (in pink - each grid cell has a unique "name"). Both layers are polygon shapefiles. I would like to calculate how much forest is present in each grid cell but I cannot find a tool that will do this in R. I'm looking for something equivalent to tabulate area in ArcGIS. As you can see, the forest polygons are complex and in many cases there are several of them per grid cell, which is making it trickier.


Where can I check which difficulty bracket I'm in?

Supposedly DOTA 2 matchmaking is divided into brackets.  I want to know which difficulty bracket I'm in. How can I find this information?


I know how www.example.com can be different from example.com. But is there really a need? Most of the time we end up setting both, www.example.com and example.com to the same IP. Is it still used only to make it more readable!?


Show that if $a+b+c=0$, $2(a^4 + b^4+ c^4)$ is a perfect square

Show that for $\{a,b,c\}\subset\Bbb Z$ if $a+b+c=0$ then $2(a^4 + b^4+ c^4)$ is a perfect square.    This question is from a math olympiad contest.   I started developing the expression $(a^2+b^2+c^2)^2=a^4+b^4+c^4+2a^2b^2+2a^2c^2+2b^2c^2$ but was not able to find any useful direction after that.  Note: After getting 6 answers here, another user pointed out other question in the site with similar but not identical content (see above), but the 7 answers presented include more comprehensive approaches to similar problems (e.g. newton identities and other methods) that I found more useful, as compared with the 3 answers provided to the other question.


How to set default file format for MS Paint

I'm using MS Paint on WinXP at work, for capturing simple screenshots. Problem: MS Paint always wants to save in BMP format. How can I set PNG to be Paint's default file-saving format?  Note: Suggestions about other software are irrelevant. I know there are many other software tools available. But I'm asking specifically about MS Paint.


How do symmetries of nature give rise to the conservation laws?

In my physics textbook, the following points are given:-   The Law of Conservation of linear momentum emerges from the homogenecity of space.  Isotropy of Space gives rise to the Law of Conservation of angular momentum.  Homogenity of time gives rise to the Law of Conservation of Energy.    However, no explanation for the above three points has been given in my book.Can someone provide explanation for the above 3 points? (If possible, please include mathematics in your explanation.)


What is a good simple easily installable app to measure download speed on Ubuntu 14.04?


Appropriate Ubuntu version for my hardware

I have a Lenovo IdeaPad 310 with an Intel Celeron processor, 4GB RAM and 1TB HDD. Which Ubuntu version I can install?


Find the directory part (minus the filename) of a full path in access 97

For various reasons, I'm stuck in Access 97 and need to get only the path part of a full pathname.  For example, the name  c:\whatever dir\another dir\stuff.mdb   should become  c:\whatever dir\another dir\   This site has some suggestions on how to do it:   But they seem rather hideous.  There must be a better way, right?


Showing $\sum |\hat{f}(n)| \leq C \cdot \int_{0}^{2\pi} |f(t)| \ dt$

If $f \in L^{1}[0,2\pi]$ define $\hat{f}(n)$ for $n \in\mathbb{Z}$ by $$\hat{f}(n) = \frac{1}{2\pi} \int_{0}^{2\pi} f(t) \cdot (\cos(nt) -i\sin(nt)) \ dt$$ Suppose $M$ is a closed linear subspace of $L^{1}[0,2\pi]$ such that $\sum |\hat{f}(n)| < \infty$ for each $f \in M$.Then how can one show that there is a constant $C$ such that $$\sum_{n} |\hat{f}(n)| \leq C \int_{0}^{2\pi} |f(t)| \ dt$$ for each $f \in M$. Can anyone help me out with a clear solution.


14.04 Cleanly upgrade to ppa:ondrej/php from ppa:ondrej/php5-5.6

I went through my usual server package upgrades today and discovered that ppa:ondrej/php5-5.6 has been depreciated and we must now upgrade to ppa:ondrej/php.  The basic provided instructions are to run:  sudo add-apt-repository ppa:ondrej/php   And then:  sudo apt-get update sudo apt-get upgrade --show-upgraded   Looking at the new repository, the names do not seem to completely line up so I think I'll need to do some apt-get installs to get all the right packages installed.  It also appears that the sub-packages (ie php-gd) will install for all php versions and may also install php 5.5 and php 7.0 ()  So my question is, what is the cleanest way to "switch" ppas and clean up the existing packages considering that this is a production server?  Should I try to remove all the packages installed from the previous PPA and/or remove the PPA from my system?  It's not yet in the main page for the PPA but the upgrade message gave deprecation as June 2016 so it's not a very long timeline to rebuild our server image.  I did find this page, which provides instructions for switching out the PHP version apache uses:


Helle everyone, I have a question regarding the exact definition of entropy.   When you look up te derivation (proof) of the Clausius-inequality, for example on wikipedia, the formula $$ d S = \frac{\delta Q}{T} $$ is used, without specifying the path to be reversible or not.   However, some definitions state that de change is entropy can only be calculated if the path taken is reversible i.e. $$ d S = \frac{\delta Q_{rev}}{T} $$  I am really struggling with this, so where am I wrong in my thinking?   Thanks in advance


Caption above subtables with subcaption package breaks numbering of following table

I use the subcaption package to display multiple tables side by side. My document follows the convention of putting table captions above the table and I would like to keep this for the meta caption at least.  If I put the caption above the subtable entries, the following table is skipping one increment in the numbering like this:  Captions below: Table 1 Table 2  Captions above:  Table 1 Table 3  This is an example of the situation that produces the wrong numbering:  \documentclass[11pt,a4paper,toc=listof,toc=bib,abstract=true,parskip=half]{scrreprt}  \usepackage{subcaption}  \begin{document} \chapter{firstchapter} \begin{table}[ht] \caption{A table with caption on top}\label{tab:1} \begin{subtable}{.5\linewidth}\centering \caption{A subtable}\label{tab:1a} {\begin{tabular}{ccc} \ $a$ & $b$ & $c$ \\ \hline 0 & 0 & 0 \\ \ 1 & 1 & 1 \\ \end{tabular}} \end{subtable}% \begin{subtable}{.5\linewidth}\centering \caption{Another subtable}\label{tab:1b} {\begin{tabular}{c c c} \ $a$ & $b$ & $c$ \\ \hline 0 & 0 & 0 \\ \ 1 & 1 & 1 \\ \end{tabular}} \end{subtable} \end{table}  \begin{table} {\begin{tabular}{c c c} \ $a$ & $b$ & $c$ \\ \hline 0 & 0 & 0 \\ \ 1 & 1 & 1 \\ \end{tabular}}  \caption{Any other table}\label{tab:2} \end{table}  \end{document}   Am I using something wrong here or is this a bug in the subcaption package? Any Input would be appreciated, I would rather not "fix" the counter manually after the table or change packages.


I see these message. Which means that terminal uses some disk cache. How to disable it using disk caches? Thanks.  "Your disk space is critially low."  Older terminal scrollback contents may be automatically discarded to conserve VM backing store".


Concat speed of String is reduce after migrating to java11

When I migrated my jdk from jdk_8u261 to jdk11.0.11, the performance of String concat speed has dropped dramatically. For example, with the following code, jdk_8u261 spends about 1ms , jdk11.0.11 spends about 500ms. I realize that jdk11 make some optimization with String concatenation, such as StringConcatFactory and some concatenation strategy. I don't see why it is worser than jdk8 in my case. Here is the demo:     // alphabet concat test     String a = "a";String b = "b";String c = "c";String d = "d";String e = "e";     String f = "f";String g = "g";String h = "h";String i = "i";String j = "j";     String k = "k";String l = "l";String m = "m";String n = "n";String o = "o";     String p = "p";String q = "q";String r = "r";String s = "s";String t = "t";     String u = "u";String v = "v";String w = "w";String x = "x";String y = "y";     String z = "z";       long t1 = System.currentTimeMillis();     String str1 = a + b + c + d + e + f + g + h + i + j + k + l + m + n + o + p                     + q + r + s + t + u + v + w + x + y + z;     System.out.println(System.currentTimeMillis() - t1);


"A" Flagged as Dupe of "B" Which was Closed as Dupe of "A"

While ♫ living it up in the CVQ,♪ * I came across a dupe question being closed as a dupe of a question which already had an answer. I thought "Hey that's silly. I should just follow the link and propose the grandparent as the original instead of some arbitrary middle question."  So I got to the grandparent, copied the URL, and went back to the CVQ to present the better dupe. I got an error:     questions cannot be duplicates of themselves   Reading the two questions again, it dawned on me:    Should this be some sort of safeguards in place for this? As entertaining as it was, it's hardly useful. But the worst part was anyone could have gone along with it, since it's not plainly obvious what's about to happen. Furthermore, the user who voted to close clearly meant to go the other way, but accidentally did it this way instead. (We've since discussed it and his vote is now retracted)  At first I thought this was a geniusly diabolical audit. It's not.  Original question:     Its flagged duplicate:     Observe that the title of the original question, and the title of the link in the question closed as dupe are identical. Circular dupiness!  * That really should be the title of the Stack Overflow theme song


What countries allow the most visa free / visa on arrival entries?

is a discussion of which passports allow the most visa-free or visa-on-arrival entries. That kinda has me wondering what the most open country is. ie. which country is the most universally easiest to get into, regardless of what country you're coming from.  Like just because UK visitors can get into a lot of countries without visa's doesn't necessarily mean that all their agreements are reciprocal and that just anyone can get into their country without a Visa. Or are visa free agreements always reciprocal?


Prove the set $\Bbb Z^+ \times\Bbb Z^+ \times \Bbb Z^+$ is countable.

Prove the set $\Bbb Z^+ \times \Bbb Z^+ \times \Bbb Z^+$ is countable.   I know you can use diagonal processing to prove that $\Bbb Z^+ \times \Bbb Z^+$ is countable, but how would you go from there?


Does square difference prove that 1 = 2?

I was mathematically shown 1 = 2 by a function that states the following  $$x^2-x^2 = x^2-x^2 $$   $$x(x-x)=(x-x)(x+x)$$  dividing by $(x-x)$ we get...  $$x=x+x$$     $$ x=2x$$      $$1=2$$  I can see that mathematically he was right, but for sure that I was missing something as it doesn't make mathematical sense


$\lim_{t \to \infty} t\mu(f > t) = 0$ but $f \not \in L^1$

I have the following question: Give a non-negative lebesgue measurable function $f$ on $[0,1]$ such that   \begin{equation} \lim_{t \to \infty} t\mu(f > t) = 0 \end{equation}   but $f \not \in L^1$  In a previous part of a problem, I was able to show that $f \in L^1$ is a sufficient condition for the limit to be $0$. I have tried stuff like $1/x$ which is not in $L^1$ but the limit is $1$ in this case. I have tried other variations like $1/x^n$ where $n \geq 0$ but none of these work. I think that $[0,1]$ having finite measure is likely relevant, but don't know how.


I have a very weird question today. I am building a huge application with jQuery, Ajax and PHP.  Basically I'm loading the contents of a div with PHP once the page loads.
     Test1     Test2     Test3
   When someone clicks on these, an alert should come up, like this:  $("#click1").on("click", function(){     alert(1); });   However if the client clicks on  Click   a jQuery function is triggered like the following:  $("#click_here").on("click", function(){     fillDiv(); });   fillDiv() function is basically calls and ajax function and fills the div with the result, the PHP page returns.  This is basically the exact same as the top div. Php returns the followig:          Test1         Test2         Test3   And the fillDiv() function places this into the samplediv. I've checked the HTML of the 2 result is the Exact same!  Problem:  When the items are loaded back from the Ajax function, with thee exact same html, IF I click on any of the Test1, Test2, Test3 links, I got back nothing actually. No alert, nothing. Not even an error message.  What could be the issue, which I didn't encounter?


Can an imprinted spell be kicked when it is cast?

Can an imprinted spell be kicked when it is cast ?  For example :  and   Can I pay the kicker cost each time I activate Isochron Scepter?


i need to upload images with md5/uniqid name.   PHP:   $filenamekey = md5(uniqid($_FILES["myfile"]["name"], true));   move_uploaded_file($_FILES["myfile"]["tmp_name"],$output_dir.$filenamekey);   This move image into folder with md5 name but upload files without any image extension/type. how can I fix this?  Pic?


object deforms strangely when using the subsurf modifier

I am trying to make an axe and stomped upon this problem...having no idea how to resolve it. 1st photo is with subdivision.  second is without.


Are coherent states of light 'classical' or 'quantum'?

Coherent states of light, defined as  $$|\alpha\rangle=e^{-\frac{|\alpha|^2}{2}}\sum_{n=0}^\infty \frac{\alpha^n}{\sqrt{n!}}|n\rangle $$  for a given complex number $\alpha$ and where $|n\rangle$ is a Fock state with $n$ photons, are usually referred to as the most classical states of light. On the other hand, many quantum protocols with no classical analog such as  and  can be implemented with coherent states.  In what sense or in what regime should we think of coherent states as being 'classical' or 'quantum'?


Multiple Regression, Normal distribution and Normalization

I am trying to run a Multiple Regression model but I am not sure what should I do to prepare the data input. In my model the dependent variable is the artificial surfaces in hectares, the independent are the GDP (monetary value) and Population (inhabitants). The histogram shows that the data is not normal distributed.    I would like to know if I need to normalize the distribution of the data in order to get the "bell" curve and/or  if I need to normalize the data (with the max-min or standardize).


Can we say "I am friends"? If not, why can we say "I’ve been friends with..."?

I’ve been friends with the Murkets for twenty years.   This is a sentence from .  How can we explain this? I thought when the pronoun was "I" we must say a friend not friends. I understand the meaning, but what about structure?    I think there should be subject and complement agreement. Sorry I cannot say what I mean in a better way! I hope you understand what I mean.


I i just bought a new dynabook with windows 10 installed on it. I achieved to install Ubuntu 19 alongside windows 10, but after it it's impossible to boot into ubuntu. I tried changing in the bios were ubuntu appears in the boot order, but it keeps booting into windows. I've also executed the bcdedit command in windows and still grub is not appearing. Any help would be appreciated, maybe it's already solved this problem, but i didn't find a solution yet :( Edit based on additional information provided as answer: I'm attaching here some screenshots asked above for further help. My computer is a Dynabook Tecra X40-F-140. I also notice that list partition is not detecting Ubuntu's partition. I created a 600 GB partition and a 1 GB swap space in the missing space (it is a 1TB HDD), the partitions created would be between partition 3 and partition 4. Boot options:  Current HDD boot options:  list partition output:  Thanks in advance!


Are term_taxonomy_id and term_id the same?

I have a custom query where I need a JOIN because I want to COUNT all the posts of a specific category.  So I checked the tables and I found out that table wp_term_relationships contains a reference to the wp_term_taxonomy table. The term_taxonomy_id.  However when I looked into the wp_term_taxonomy table again I found out that term_taxonomy_id and term_id are having the exact same values.  So are they always the same? Can I filter the results by category with only joining wp_term_relationships and using term_taxonomy_id?


Quick way to find a value in HTML (Java)

Using regular expressions, what is the simplest way to fetch a websites HTML and find the value inside this tag (or any attribute's value for that matter):  <html>   <head>   [snip]   <meta name="generator" value="thevalue i'm looking for" />   [snip]


How to fit a glm with sum to zero constraints in R (no reference level)

Question has been rewritten  I am trying to fit a glm to find out how the rate of events happens (counts/exposure) related to some covariates, with Poisson error. Counts is the number of events happened and the covariates include age, sex, smoking status, policy class and exposure, where policy class has 6 levels: class 0, class 1, ..., class 5  I was wondering how to:   keeping the intercept (if possible? if not please would you explain me why not). [Answered by Affine] making the coefficients of polclass0, ..., polclass5 sum to 0, I know somehow I need to use contr.sum, but it doesn't work (see below) [An example from , but I couldn't replicated it.  I used the +0 in the formula to make the polclass0 "take over" the intercept. However, is it possible to have other categorial variable (e.g. sex, or some categorial variable that takes 3+ values) to have two all coefficients display?     Example:       set.seed(123)     sex <- as.factor(sample(c(0,1), 50, replace=T, prob=c(0.5, 0.5)))     smoker <- as.factor(sample(c(0,1), 50, replace=T, prob=c(0.3, 0.7)))     polclass <- as.factor(sample(0:5, 50, replace=T))     age <- sample(16:80, 50, replace=T)     count <- rpois(50, 2.5)     exposure <- rgamma(50, 100)      glm1 <- glm(count ~ polclass + sex + smoker + age + offset(log(exposure)) + 0 ,                 family=poisson(link='log'), contrasts = list(polclass = contr.sum))      summary(glm1)           Call:         glm(formula = count ~ polclass + sex + smoker + age + offset(log(exposure)) +              0, family = poisson(link = "log"), contrasts = list(polclass = contr.sum))          Deviance Residuals:              Min       1Q   Median       3Q      Max           -2.3604  -0.5625  -0.1263   0.5246   1.5584            Coefficients:                    Estimate Std. Error z value Pr(>|z|)             polclass0 -3.719037   0.423105  -8.790   <2e-16 ***         polclass1 -3.347628   0.328248 -10.198   <2e-16 ***         polclass2 -3.638992   0.368175  -9.884   <2e-16 ***         polclass3 -3.833882   0.426819  -8.982   <2e-16 ***         polclass4 -3.780837   0.399512  -9.464   <2e-16 ***         polclass5 -3.838007   0.373120 -10.286   <2e-16 ***         sex1      -0.057738   0.091936  -0.628    0.530             smoker1   -0.174328   0.118654  -1.469    0.142             age       -0.001846   0.006362  -0.290    0.772             ---         Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1          (Dispersion parameter for poisson family taken to be 1)              Null deviance: 8764.667  on 50  degrees of freedom         Residual deviance:   40.865  on 41  degrees of freedom         AIC: 189          Number of Fisher Scoring iterations: 5   as you can see, the contr.sum doesn't work and I would like to know why and how to do that exactly?  Thanks in advance!


Every group of order 111 is cyclic. (True or False)

By Lagrange's theorem the possible order of the subgroups of the group will be 1 or 3 or 37 or 111  Now by Sylow's 1st theorem this group must have a subgroup of order 3 and as well as 37.  Then we can prove that every abelian group of order 111 is cyclic.  Now my question is:  Is there be any non-abelian group of order 111?  If there be a non abelian group of order 111 then the given statement is False otherwise the statement is True .  Thanks.


I was trying to render my scene, and the render turned out very blurred. (It is not supposed to be blurred). Is there a setting that I am missing somewhere which is making it look like this?


In a NOR gate not connected to any power supply, how can the output be '1' if both of the inputs are '0'?

I was reading about SR Latches and this very weird (and silly) question popped up in my head.  Here, when A and B is 0, then Q is 1. Suppose that this NOR gate is lying in air, not connected to any power supply. Then as there is no potential or current passing through A or B, we can say that the inputs are 0 and 0. Then according to the truth table, Q must be 1! How is that even possible? What does it even mean?


Groups with single conjugacy class of subgroups.

I wish to know all those groups in which there is single conjugacy class of subgroups of fixed order.For example, In finite cyclic groups and in Alternating group of degree 4, number of conjugacy class of subgroups of fixed order is one. But I am unable to search a general result. Please Help me.


hi, im new to blender. I was wondering if there was a way to use python to print a list of coordinates of edges or save into a text document like this:  x:(the coordinates of one end of the edge)  1  2  3  so on  y:  1  2  3  z:  1  2  3  x2: (the coordinates of the other end of the edge)  1  2  3  y2:  1  2  3  z2:  1  2  3  ignore bullet points I'm using them to separate lines


Boot Ubuntu from a bootable USB hangs on purple screen

I recently bought a laptop (Lenovo Y410P) with Windows 8 pre-installed and I'm trying to dual boot Windows 8 and Ubuntu 13.0.  I created a bootable usb using Pendrive. Then I changed the Boot Mode to Legacy Support and the boot order so it boots from the flash storage first. When I restarted the computer, I got the error message  "SYSLINUX 4.06 EDD 2012-10-23 Copyright (c) 1994-2012 H. Peter Anvin et al"  and it just hung there.   Fair enough. After some googling I formatted my flash drive in FAT format instead of FAT32. The "SYSLINUX..." error message is gone but now it hangs on a purple screen    Does anyone have a suggestion what to do here? I've looked at various posts but none of them seems to have a solution that the author confirmed it worked.


I have 2 std::vectors, one float, one integer: A and B.  A = [5,3,1,2]  B = [0.1, 0.2, 0.3, 0.4]  I want to sort A and maintain the same 1-1 in B. So the result should look like:  A = [1,2,3,5]  B = [0.3, 0.4, 0.2, 0.1]  I used python/js convention for convenience, but these are C++ std::vectors. I was considering just making a tuple struct and packing these into a std:vector of tuples, overloading the sort comparator. Is there more lazy way of doing this?


How do I disable the blinking cursor in gnome-terminal?

I could have sworn that there was once a setting for this in the gnome-terminal "Profile".  And then in some version of Ubuntu, that setting disappeared, and I had to use System ➜ Preferences ➜ Keyboard to uncheck "Cursor blinks in text fields".  Well, neither of those seems to be working now.  So how do I make the cursor stop blinking?


Prove that $ \sum_{k=0}^m {m \choose k} {n \choose r+k} = {m+n \choose m+r}. $

Use a combinatoric proof to prove that:  $$ \sum_{k=0}^m {m \choose k} {n \choose r+k} = {m+n \choose m+r}. $$  I've had a couple of ideas on how to tackle this - first, I tried to see if I could divide m and n into two separate committee/groups of size m and n. But I wasn't able to figure out what the combination would represent. Then I tried to imagine whether it was equivalent to C(n,r) summed over m possibilities, but that doesn't seem correct either.  Any help?


Clean up the list of options shown when opening my Gmail account

When opening Gmail (email account) - clicking on the Gmail icon opens my daily account but I have others - so I highlight the daily email address and a dialogue box opens with possible options, including other email addresses I use or attempted to create.   I want to take those out - delete them. I don't like how junky it has gotten through the years. How do I delete these address/attempted addresses from the Gmail address dialogue box?


Why is $\sqrt{ab} = \sqrt{a} \sqrt{b} $ where a and b are positive real numbers?

That's the question.  I try to explain this to myself I can't find any good resources.  Note: I have researched for about 15 mins and yet haven't found the answer. I do apologize for any inconveniences.


While reviewing a post another one appeared when I was finished. This second post was difficult to comprehend so much I didn't know who was posting and who was attempting an edit. Of course it is marked, but again both were such a mess (I suspected maybe ESL?) that I decided to attempt an edit so I could see what the result was going to be.  I was given a notice that this was some sort of system test that indicated I was in error in editing what was an attempt to deface a post. It pointed out my failure, but I intended on cancelling this edit, but wasn't given the chance.  Maybe this could be adjusted so it waits until the laast step before assuming someone is making an error? This is the only feedback I've ever had for my reviews. Now I'm not sure if I'm doing this correctly at all.  Here was the post:


Can I have a 4 GB RAM (1600 MHz-1.35V-DDR3) and a 2 GB RAM (1333 MHz-1.5V-DDR3) at the same time to my laptop?

Currently my laptop has a:   4GB RAM DDR3, 1.35V, 1600MHz.   I am wondering if I could add to the other slot of my laptop another RAM which has the following specs:   2GB, RAM DDR3, 1.5V, 1333 MHz   so, overall my new system will have 4 + 2 = 6 GB of RAM   Is it possible or may I face any problem in the future due to different frequency, voltage and capacity?  Thank you


Help identifying an error type "tried to help me learning"

I have a friend from Russia who is trying to learn English and recently used the sentence "He tried to help me learning..." (implied: the English language)  It is obviously wrong and I corrected it telling her that she was supposed to say: "He tried to help me learn.", but I have a hard time explaining to her why it is incorrect since I'm not an expert on grammar either.  Is it a case of confusing the present simple and present continuous or does it have something to do with gerunds and infinitives? Any help would be highly appreciated!


javascript event for each time element exists

An external script that I use, generates divs of a certain class from time to time, it can happen unlimited amount of times. I'm trying to run a function each time such element is being created. I tried using $('selector').live(function(){}) and $('selector').waitUntilExists(function(){}) but it's only valid for the first time it's created. how can I create some kind of a listener that will call a function each time a new element of this class is being created?  Thanks


I'm having an issue here. Why does the code below give out a wrong output?  test = '{:.{}f}'.format(35.72506789023292, 15) print(test)  >> 35.725067890232921   isnt it supposed to give me this?:  >> 35.725067890232920   i tried different numbers but they also fail. How can I make this work? I read regarding floats in Python and it is stated that it give accurate decimal digits for upto 16. This example only has 15 so it should be enough for float handling.


How to back up and restore chrome in ubuntu?

I back up chrome in Windows with , That it saves a file with *.gcb format. Now, How could I restore it in ubuntu 11.10 ?  in other word: How could I back up and restore chrome in ubuntu?


Why can't I log into the old Minecraft: Java Edition launcher? Throws InvalidCredentialsExeption

I know for a fact that the information is right, but when I try to log in, it says: InvalidCredentialsException: Invalid credentials. Invalid username or password. The launcher's version is 1.6.89-j (the java version, the program executes a javabinary). Also, if it helps, I am on Debian 8, 32-bit (I know I can't use the newer versions, I only want to run the older ones that support the 32-bit LWJGL).


I want to understand the  intuitively, away from any mathematical proof.


Answer Says $\lim_{(x,y)\rightarrow(0,0)}\frac{x^3y^2}{x^4+y^6} = 0$. I say DNE. What did I do wrong?

I was asked to find  $$\lim_{(x,y)\rightarrow(0,0)}\frac{x^3y^2}{x^4+y^6}$$   Observe that setting y=mx results in $$\lim_{(x,mx)\rightarrow(0,0)}\frac{x^3(mx)^2}{x^4+(mx)^6} = 0$$ The textbook solution then proved that the limit is 0 using the squeeze theorem.  However, I tried to set y=x^(4/6) and I got: $$\lim_{(x,y)\rightarrow(0,0)}\frac{x^3(x^{\frac{4}{6}})^2}{x^4+(x^{\frac{4}{6}})^6} = \lim_{x\rightarrow0}\frac{x^4}{x^4+x^4} = \frac{1}{2}$$  So I concluded that the limit does not exist.  I am not convinced that my solution is correct, I would really appreciate to know the reason why I am wrong.   Thank you


changing the names of files within a directory

I have few files under a particular directory. These are the files  idex.1.ebwt  idex.2.ebwt  idex.3.ebwt  idex.4.ebwt  idex.rev.1.ebwt  idex.rev.2.ebwt   I want to change the names of the file from idex to index keeping the rest of the name same. Basically I want to replace idex with index  Any one line command?


Factor $x^5+x^2+1$ into irreducible polynomials in $Z[x]$

So here is my question: i would like to determine if whether or not the polynomial $x^5+x^2+1$ in $Z[x]$ is irreducible and if not then find the factors.  I tried a lot to find it. I really think it is already irreducible but I don't know how to prove it.  I tried Eisenstein's criteria which doesn't work here, I tried to check this criteria also after changing $x$ as $ax+b$ but everything I check was too complicated.  I tried for the modulus with prime numbers of $Z$, and I'm not sure of my following argument:  The polynomial $\mod 2$ stays $x^5+x^2+1$.  But if $x$ is odd then $x^5$ and $x^2$ are odd too. Then the polynomial is given by $1+1+1=3=1 \mod 2$ which is irreducible (not sure if I have the right to say that).  And if $x$ is even, then $x^5$ and $x^2$ are even too. The polynomial is thus given by $0+0+1=1 \mod 2$ which is irreducible.  Hence the polynomial is irreducible $\mod 2$ and since it's a monic polynomial it implies it is irreducible in $Z[x]$  Is my argument correct? If not if you have any clue please I would like to have some :)  Thank you and good night!


How can we remove or reset Windows passwords in Windows 8, without logging in to windows first?  In Windows 7, I used Hirens but it is not working for Windows 8.    I am talking about local user account password not Microsoft online accounts like @hotmail.com or domain accounts those can be reset.   The scenario is a computer running Windows 8 with a local only user and the client forgot the password to the only active account. Is there a way to remove or reset that password?


If $f\colon \mathbb{R} \to \mathbb{R}$ is such that $f(x+y)=f(x)f(y)$   and $f'(0)$ exists, then $f$ is differentiable on $\mathbb R$.   I know how to show it is continuous but no clue how to show differentiable.


why is it okay to use "is" in front of "interested"

Is it grammatically right to say: "If he is interested in the project, he will ask you many questions"   It sounds alright to me and I noticed this uses future simple tense, however, I'm curious to know why it is acceptable to use the word is before the past tense word interested


Tikz/Forest: highlighting level background

I am using the Forest package and I am trying to paint a gray background for odd and even rows, as well as a label.  I already had a version of this diagram that I wrote "manually" with tikz. But it was laid out horizontally (I want it to be vertically laid out, as in the code), and there were also some changes I wanted to make. I was trying to do it from scratch using Forest...    The code I am stuck trying to draw the background .. (I can seem to be able to paint beneath the tree ..)  \documentclass{standalone}  \usepackage{forest}  \begin{document}  \begin{forest} for tree={draw, circle, l sep+=0.5em, inner sep=0.05em} [,fill     [{$-$}, edge label={node[midway,left]{$0.70$}}         [$-$, edge label={node[midway,left]{$0.78$}}             [$-$, edge label={node[midway,left]{$0.80$}}                 [$-$, edge label={node[midway,left]{$0.82$}}]                 [$+$, edge label={node[midway,right]{$0.18$}}]             ]             [$+$, edge label={node[midway,right]{$0.20$}}                 [$-$, edge label={node[midway,left]{$0.49$}}]                 [$+$, edge label={node[midway,right]{$0.51$}}]             ]         ]         [$+$, edge label={node[midway,right]{$0.22$}}             [$-$, edge label={node[midway,left]{$0.50$}}                 [$-$, edge label={node[midway,left]{$0.70$}}]                 [$+$, edge label={node[midway,right]{$0.30$}}]             ]             [$+$, edge label={node[midway,right]{$0.50$}}                 [$-$, edge label={node[midway,left]{$0.57$}}]                 [$+$, edge label={node[midway,right]{$0.43$}}]             ]         ]     ]     [{$+$}, edge label={node[midway,right]{$0.30$}}         [$-$, edge label={node[midway,left]{$0.50$}}             [$-$, edge label={node[midway,left]{$0.71$}}                 [$-$, edge label={node[midway,left]{$0.75$}}]                 [$+$, edge label={node[midway,right]{$0.25$}}]             ]             [$+$, edge label={node[midway,right]{$0.29$}}                 [$-$, edge label={node[midway,left]{$0.53$}}]                 [$+$, edge label={node[midway,right]{$0.47$}}]             ]         ]         [$+$, edge label={node[midway,right]{$0.50$}}             [$-$, edge label={node[midway,left]{$0.50$}}                 [$-$, edge label={node[midway,left]{$0.72$}}]                 [$+$, edge label={node[midway,right]{$0.28$}}]             ]             [$+$, edge label={node[midway,right]{$0.50$}}                 [$-$, edge label={node[midway,left]{$0.44$}}]                 [$+$, edge label={node[midway,right]{$0.56$}}]             ]         ]     ] ] \draw[draw=none,fill=black!2] (-5,-2) rectangle (5,-3); \end{forest}  \end{document}


Show that $\gcd(a,b)=d\Rightarrow\gcd(a^2,b^2)=d^2\ $

Show that if  $\gcd(a,b)=d\Rightarrow\gcd(a^2,b^2)=d^2\ $    $\gcd(a,b)=d\Rightarrow\ d\mid a,b\Rightarrow\ \ d^2\mid a^2,b^2\Rightarrow\ d^2\mid\gcd(a^2,b^2)$. But to complete  the proof we must show that: $\gcd(a^2,b^2)\mid d^2$ How can I achieve this?


What off-camera flash solution should I use with an entry-level Nikon?

I want to start experimenting with off-camera flash and have a Nikon SB600 + D3000. I plan to upgrade my body in the next year so would like to purchase something which is:  a) wireless, and  b) will be compatible if I upgrade to a D7000 or the D300s/700 replacement when it comes out.  Any recommendations appreciated. Thanks!


Blender is seriously broken for me all of a sudden? What is going on?

So I haven't used Blender too much in about a week or so. I decided to open up some of the last things I was working on and was horrified at what I saw. At first, it was hard to tell what was going on exactly, and I still don't know what is happening, but it looks like some severe rendering bug related to shaders. I can't even really describe in words what is happening because it's so weird. But basically, when I go into Material Preview or Rendered View, my mesh goes completely broken and gets some weird, warped, transparent property. I've recorded a video with a new file.  I think this might be related to my updating my video card driver a couple days ago. I would revert, but the reason I updated it because otherwise Steam wouldn't launch. Has anyone else seen anything like this before? I've reinstalled already. Is this some severe bug or am I being really stupid here?


Can I safely restore Windows while keeping my Linux partition?

Currently, my computer is dual-booting Linux and Windows 7. A series of unfortunate events has led to me needing to restore Windows using a restore disc.  I want to know if this can be done without formatting my entire hard drive, as I don't want to get rid of my Linux partition. That is, I want to reset Windows - which already has a partition on my hard drive - without affecting any of my other partitions on my drive.


"Undefined control sequence" at beginning of any simple document

Very new to Tex. Trying to get the most basic doc to work. Not matter what I do I always get an "Undefined control sequence" at line 1 of my document. As of now, I am only trying to build the following:  \documentclass{article} \begin{document} This is a test of the article \end{document}   Full error is:  This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013)  restricted \write18 enabled. entering extended mode (./example.tex ! Undefined control sequence. l.1 \documentclass                   {article} ?   I have tried many other variations, including \usepackage directives that people mentioned - nothing every varies.


Emoji characters not displaying correctly on Windows 7

Is there a specific font or something I need to install/download/configure in order to see emoji characters?   are picture characters/emoticons often used in Japanese webpages and messages.   People can post these from their phones to a site like Twitter, but when I try to read them on my PC (running Windows 7) it doesn't know how to display them.  If there's a reason I can't display them on my machine, is there a reason why not? They're part of unicode, after all.


I have got Win 8 on my SSD and I want to install Ubuntu on my HDD. Can I? Thanks. My SSD is 120 GB and when I try to access it gives this error in "trying Ubuntu" :  Error mounting /dev/sda2 at /media/ubuntu/2284BD1E84BCF57F: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=999,gid=999,dmask=0077,fmask=0177" "/dev/sda2" "/media/ubuntu/2284BD1E84BCF57F"' exited with non-zero exit status 14: Windows is hibernated, refused to mount. Failed to mount '/dev/sda2': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.   Thanks for advance.


Calling __new__ when making a subclass of tuple

In Python, when subclassing tuple, the __new__ function is called with self as an argument. For example, here is a paraphrased version of PySpark's Row class:  class Row(tuple):     def __new__(self, args):         return tuple.__new__(self, args)   But help(tuple) shows no self argument to __new__:    __new__(*args, **kwargs) from builtins.type       Create and return a new object.  See help(type) for accurate signature.   and help(type) just says the same thing:  __new__(*args, **kwargs)       Create and return a new object.  See help(type) for accurate signature.   So how does self get passed to __new__ in the Row class definition?   Is it via *args?  Does __new__ have some subtlety where its signature can change with context? Or, is the documentation mistaken?   Is it possible to view the source of tuple.__new__ so I can see the answer for myself?  My question is not a duplicate of  because in that question, all discussion refers to __new__ methods that explicitly have self or cls as first argument. I'm trying to understand    Why the tuple.__new__ method does not have self or cls as first argument. How I might go about examining the source code of the tuple class, to see for myself what's really going on.


Are there any must read physics books for beginners?

I am in 9th grade and have recently become interested in physics. I have a basic understand of relativity, electromagnetism, and a bit of knowledge about on quantum mechanics. However, I don't have much of an understanding at all about the mathematic of these subjects and would like to learn. I am just starting geometry and have completed algebra. Any suggestions for books or online recources to help me?


What is a good replacement for a cable end cap?

I was adjusting the tension of my front derailleur cable and managed to pop off the cable end cap. The cable is now quite frayed at the end and I think it would be difficult to attach another cap.  What would work as a suitable replacement for a cap? I've read that perhaps superglue or duct tape could work?


I am trying to solve the problem:     \begin{array}{l}{\text { A particular solution of the differential equation }} \\ {x \frac{\mathrm{d} v}{\mathrm{d} x}=f(v) \text { has } v=2 \text { when } x=\mathrm{e} \text { . }} \\ {\text { If } k \text { is the value of } v \text { when } x=1, \text { show that } \int_{k}^{2} \frac{1}{f(y)} \mathrm{d} y=1}\end{array}   I realize that: $\int\frac{dv}{f(v)} = \int \frac{dx}{x}$. I am unsure of how to proceed.


SerialVersion UID Java - How SerialVersionUID work?

Hello I've one question about SerialVersionUID in Java. If I generate a SerialVersionUID for class A,  2 instances of A have the same SerialVersion about class and another unique Serial for the object, different about object1 and object2? Or how?  I don't understand, please reply me. Thanks.


Installing debian package through Synaptic

I want to install a .deb file. After going through various questions, I came across these three options: dpkg, GDebi and Ubuntu Software Center. However, I want to install the. Deb file via Synaptic Package Manager only. Is there any method by which I can install. Deb file as well as all it's dependencies via Synaptic Package Manager?


“Firstly, secondly, thirdly,…”, what comes next?

Similar to this   How would you complete the following sequence, until point 10?   Firstly Secondly  Thirdly ...   Any help would be appreciated.


how to test if there is a link to a specific node socket?

Building a blender 2.8 helper addon to automatiz tasks, I need to test if a node is connected to Principled Alpha socket. If not, I will connect A RGB node. I fail to check "if any node connected : do something" ... following code works but I can't do anything if nothing connected found  for m in bpy.context.object.material_slots:     mat = m.material nodes = mat.node_tree.nodes     for mat_node in mat.node_tree.nodes:     if mat_node.type == 'BSDF_PRINCIPLED':         print(mat.name + " "+ mat_node.name +" :" )                     alphasocket = mat_node.inputs[18]         #print(alphasocket)         node_in = mat_node.inputs         #print(node_in)                for n in alphasocket.links:                            print(n.from_node.name +" connected to Alpha")


Prove by Mean Value Theorem $\frac{x}{1+x}0$

Prove for $x>0$ $$ \frac{x}{1+x}<\ln(1+x)<x $$ I tried writing $\ln(1+x)=\ln(1+x)-\ln(1)$ and using the MVT for the $(1,1+x)$ interval. I eventually could prove the inequality but how do I have to prove even for $(0,1)$


How to add bookmark that connects to local server?

Usually I start my terminal and login to some server with the following line:  ssh -X myuser@myserver.de   Now I would like to add a bookmark so that I can login while brousing through the folders with my mouse.   When I add network bookmark I can only edit the location, the following does not work  network:///myuser@myserver.de   I remember that I was able to add such a bookmark on a different computer. There I could add something like the username, host, port etc.   I use ubuntu 12.04. Please let me know how to add the bookmark.


Thought Experiment - Poking a stick across a Black Hole's Event Horizon

The classical explanation of a black hole says that if you get to close, you reach a point - the event horizon radius - from which you cannot escape even travelling at the speed of light. Then they normally talk about spaghetti.  But here's a thought experiment. What if I have a BH with event horizon radius R such that the gravitational gradient at the event horizon is far too weak for creating pasta. I build a Ring with radius R+x around the BH. Then I lower a pole of length x+d from my ring towards the BH, so that the tip passes beyond the event horizon.  Now what happens when I try to pull the pole back?


Nested exponent modulus, $2^{2^{517}} \pmod {23}$

I have had a go at this for a while now and can't seem to get anywhere.  $$2^{(2^{517})} \pmod {23}$$  I see that Fermat's Little Theorem must come into play but I can't see where to pull $22$ from. Any help would be appreciated.  Here is my attempt:  $$2^{(2^{517} \!\!\mod {22})} \equiv  2^{(2^{517})} \pmod {23}$$ Then proceed to do Chinese remainder theorem to find the exponent?


Tool for straightening a bent metal bar of the gate?

Someone's car hit our metal bar gate, so one of the rods is bent as shown in the photo. What kind of a tool can I use to bend this back, so it's straight? Thank you!


If $x,y$ are positive reals such that $x+y = 2$ show that $x^3y^3(x^3+y^3) \leq 2$.   I thought about working backwards on this one. We can try to prove that $x^3y^3(x^3+y^3) \leq 2$ is true by first realizing that $x^3+y^3 = (x+y)(x^2-xy+y^2)$ and substituting in for $x+y = 2$. We then get $x^3y^3(x^2-xy+y^2) \leq 1$. How do I prove this is true?


How is interpolation related to the concept of regression?

Explain briefly What is meant by interpolation.How is it related to the concept of regression?  interpolation is art of reading between the lines of a table and in elementary mathematics the term usually denotes the process of computing the intermediate values of a function from a set of given or tabular values of that function.  I can't give the answer of second question.


Compute the infinite sum $\sum_{k=1}^{\infty}k^2(\frac{1}{2})^{k-1}$

I would like to compute the infinite sum $$\sum_{k=1}^{\infty}k^2\left(\frac{1}{2}\right)^{k-1}$$   How is that possible?   I tried to use the derivative method and got stuck here:  $$  \frac{d^2}{d^2x}\frac{1}{1-x}=\sum_{k=1}^{\infty}(k^2-k)x^{k-2} $$  How can I continue from here? What manipulations am I allowed to do to reach the exact form?  Thanks!


What is the difference between Vi and Vim?

I would appreciate it if someone can let a newbie know what the differences are between vi and vim. I've heard Vim is a successor to vi but whenever I try to open vi in Ubuntu it opens vim instead.


Is MacKeeper a contoversial App that new Apple Users should be educated to stay away from?

I see adverts for this particular app all over the place. Is it true that people should stay well away from it, as it could potentially do more harm than good to your Apple Computer, and to your wallet!!


GIMP Image Auto-Align Plug-In: I. just. do. not. get. it. Sorry!

Dammit Jim, I'm a photographer not a computer expert!  I have tried to use GIMP's Auto-Image-Alignment plug-in and everything's there but I just do not get how it works!  I have 100 pictures of our garden in different seasons, all taken from the same exact spot, but subtle shifts in the camera placement make the animated version of these images too jittery to watch.  I was hoping the auto-align plug-in for GIMP would solve my problems, but I just do not get how it works.  I've been tring for like three weeks now.  Can some kind soul PUH-LEEZE just write down the steps for you you would align and crop and save, say, 100 similar but slightly misaligned photos?


Should the "e" in "'ello 'ello 'ello" be capital at the beginning of a sentence?

If the the sentence is started with "'ello 'ello 'ello" should the "e" at the beginning be capital or should I count the omitted "H" still and have it lower case? Because I don't want to be ungrammatical as well as being arrested for impersonating a police officer...


[time] nouveau 0000:68:00.0: i2c aux 0003: timeout 01119000  or  [time] nouveau 0000:68:00.0: i2c aux 0007: timeout 01119000  after install Ubuntu 18.04 and booting into it, I get these messages while [time] is the specific timestamp.


GPS PPS signal corresponds to data time?

I currently have an Adafruit Ultimate GPS connected to an Arduino that outputing GPS data (nmea sentences) once per second.  There is also a pin on the GPS outputting 1 PPS signal.    My question is whether the pulse of the PPS suppose to match the time that the GPS data is coming in i.e are they are coming in at the same time?    Also does PPS pulse come in at the beginning of a UTC second or is it random and simply once a second?


Finding Command-Line Arguments of Programs

I know that unix has man pages, but is there a place I can look to discover command-line arguments of programs? Going to command prompt and typing notepad /? doesn't give anything.


This is my question: Prove that there is no subgroup with size 6 in the symmetric group $A_4$.  What i thought is that $A_4$ has all the 2,4 circles,a subgroup with order 6 must be cyclic so there is no element in $A_6$ with order 6 so there is no subgroup with size 6.  I want to be sure that I am right,  thanks.


is there a way to move launcher to the right side of screen in 14.04?

Is there a way to move the launcher to the right side of the screen in 14.04? everything that pops up in searches is only for moving to the bottom.


Why should I install hardware drivers if my computer is working fine?

I've just installed Windows 7 on my PC.  I went online to look for drivers. For , Foxconn offers LAN drivers, on-board audio drivers, and chipset drivers. And for , Nvidia offers a graphics card driver, obviously.  But then I stopped and wondered... what benefit would I gain from installing them?   The LAN cable is plugged in and I'm online; no problems there.  The on-board audio is working fine.  A quick Google tells me that a chipset is responsible for moving data around my motherboard – which seems to be happening OK!  And my graphics look perfect.    So why should I install the drivers? What would they give me, other than badly designed "management" interfaces, and pointless "notifications" whenever I plug in an audio jack?  If there are different considerations for each of the components – chipset, audio, LAN, and graphics (and any others you think I should be aware of) – please break it down in your answer.     Update: I've had a couple of answers already, saying that I'll get better stability, bugfixes, etc.   Can I slightly expand my question... Can I get all these same benefits if I install the drivers via Windows Update? And if I do this, would I avoid having to install the vendor-specific UIs, which I find so annoying?


Different p-adic topologies on $\mathbb{Q} $ are homeomorphic

Endow $\mathbb{Q}$ (the rationals) with the p-adic (resp. q-adic) topology, where p,q are primes. Are these topological spaces homeomorphic ?  I know the norms are not equivalent, therefore do not induce the same topology. What I am asking is if the two distinct topologies are homeomorphic to one another. The reason I am asking is that I know that $\mathbb{Q}_p$ and $\mathbb{Q}_q$ are homeomorphic to eachother.


Been working on this fire simulation.  I'm new to the simulation but have done a ton of fiddling around with settings and looked at some questions.  Why is the domain not rendering correctly?  It's rendering as a solid cube (bottom picture) instead of the simulation.  Also, I am in Cycles Render.  Thanks in advance,  Tyler


If I buy Minecraft on PS4, will I get a Premium license for the PC version?

If i buy the PS4 edition of Minecraft and sign in with my Mojang account, will I also be granted a premium license for the PC edition of the game?


How to know file system of any medium like hard disk, CD/DVD, flash drive?

Is there any command or any way to know what file system is there on a medium like hard disk or CD/DVD or flash drive etc. From GUI gparted one can know the type on hard disks/pen drive but not of CD/DVD.  I ran the below command to mount my DVD.  ravbholua@ravbholua-Aspire-5315:~/Documents/Other$ sudo mount -t iso9660  /dev/cdrom ~/Downloads mount: block device /dev/sr0 is write-protected, mounting read-only mount: wrong fs type, bad option, bad superblock on /dev/sr0,        missing codepage or helper program, or other error        In some cases useful info is found in syslog - try        dmesg | tail  or so  ravbholua@ravbholua-Aspire-5315:~/Documents/Other$   From the error thrown by mount, I feel that the file system that I had given in the command i.e. 'iso9660' may not be right. From this it strikes my mind to 1st know the f.s. present on the DVD. I'm working on Ubuntu 13.04.


I am getting a wrong result when I perform the following operation  $n1 = 178.200; $n2 = 89.100; $n3 = 178.199; $n4 = 89.101; $n5 = 170.999; $grandTotal = $n1+$n2+$n3+$n4+$n5; $discount = 700.000; $netTotal = $grandTotal - $discount; echo "Grand Total:".$grandTotal."
"; echo "Discount:".$discount."
"; echo "Net Total:".$netTotal."
";    Output:  Grand Total: 705.599 Discount: 700.000 Net Total: 5.5989999999999   But 705.599-700.000 = 5.599 right ?   Why Im getting this 5.5989999999999 ?


I was reading  today and I saw  question. Please take a look at the question and Brevan Ellefsen's answer.  The question asks about taking the derivative of f(x)=x^(2*x^(3*x^(4*x^(5*x^(6*x^(7*x^(...))))))) (looks like SO doesn't support LaTeX)  Brevan Ellefsen didn't really answer the question, but took a numerical approach to the function. Motivated from that answer, I tried to implement the function in Python. I don't have any experience in numerical methods but I really like these kind of coding.  So here is my code:  # Precision is set to 50. def f(k, x):     if (k < 1):         # First argument cannot be less than one.         return -1     try:         temp = 1         for i in xrange(k):             temp = (k-i)*(x**temp)         return temp     except TypeError:         # k should be an integer.         return -1   Now I'm calling the function for k = 4 and x = 0.5 and I'm comparing my function's output with WolframAlpha's output. Here are the results:  0.43854381197983005602480943707632832229137420654297 <-- My output 0.43854381197983004379857027951312617339018977615169 <-- WolframAlpha's output   As you can see, after some point, the ouputs are very different. It's not a very big difference but still enough to make me curious.   Why is this happening? For this part,  one is helpful and I've already seen it months ago, so I'm a little aware of floating number behaviour but I wasn't sure that was the reason in my case when I posted my question in the first place. I will still need help for the following ones anyway. Is my function not working properly?   If so, how should I fix it? If it's OK, which result is more precise? How can I optimize my code?


I am having a small doubt regarding maximum of random variables. I have $$Z= \max\{ X_1, X_2,\dots X_p, \dots X_N\}$$ where all $X_i$ are independent, identically distributed. Now, If for sure, I know that $$X_p>X_{p+1}>\dots>X_N$$ the can i say that the CDF of $Z$,  $$\begin{align*}P(Z<z)&= P\left(\max\{ X_1, X_2,\dots X_p, \dots X_N\}<z\right)\\&=P\left(\max\{ X_1, X_2,\dots X_p\}<z\right)\\&=\left[P(X_1<z)\right]^{N-p-1}\end{align*}$$  How to find CDF of $Z$ in this case ? Is there any theorem that reduce the size of total variables for certain condition  ?


How to install the amd Catalyst drivers in Ubuntu?

I am wondering has anyone had any luck installing the catalyst drivers on 13.10 and I have had some trouble in the past on 13.04 with kernel 3.10, and before I upgrade it would be nice know that everything will be in working order.


Interference at the focus of a convex lens or a concave mirror

Now consider parallel rays travelling towards the convex lens. After emerging they get converged at the focus. Won't this lead to interference between light rays? Practically it should but I would like to know why this does not happen.    Look at the focus in the above image. The rays get converged and shouldn't that lead to interference. Similar phenomenon should occur with a concave mirror at its focus.


What is the benefit of a wide-aperture lens if you stop it down?

As an example, say you have two lenses:  300mm f/2.8 being used at f/8 300mm f/4 being used at f/8  My understanding is that by definition the amount of light coming through the aperture means that you will still have to take both shots at the same shutter speed (for the same exposure).  That said, why then pay for a lens that can work down to f/2.8 if, for example, you're going to use it regularly at f/8? (eg. at f/2.8 sometimes the depth of field can simply be too shallow - in the above example, take bird photography).  Some have told me the f/2.8 lens requires more glass to achieve f/2.8 and therefore it lets in more light and can shoot at a faster shutter speed at the same aperture - but I really don't think that makes sense.  The only other possibility that makes sense is that typically lens manufacturers will produce a better build quality on a lens that can achieve f/2.8, so, for example, you might get sharper images because of better build quality, but that has nothing to do with the lens' ability to stop to f/2.8.


Why the empty set is a subset of every set?

I'm trying to understand why the empty set is a subset of every set and this is my reasoning (please correct me if I'm wrong):  By definition of a set S is a subset of a set A if all it’s elements are in A. ∅ has no elements if ∅ is not a subset of A then there is an element in ∅ that is not in A but ∅ as not elements. So ∅ is a subset of A by contradiction.  does it really follow that because the empty set has no elements it is a subset of every set? I mean imagine this: I have a box with nothing in it (the empty set). then I have a box with something in it (3 balls if you will). how is "nothingness" (if I may call the element of the empty set that) be in a box that has something in it already (the three balls).


I have problem while installation with packages

This is the error while installing packages:  dpkg: error processing crossplatformui (--configure): subprocess installed post-installation script returned error exit status 2


When I use variable within glob expression like gunzip *_{${X}}.gz it does not work. Here is an example: [nir@etl-dev test]$ ll total 96 -rw-rw-r-- 1 nir nir 22431 May  6 10:35 a20210427_AA.gz -rw-rw-r-- 1 nir nir 22431 May  6 10:36 a20210427_BB.gz -rw-rw-r-- 1 nir nir 22259 May  6 10:35 a20210427_LR.gz -rw-rw-r-- 1 nir nir 22431 May  6 10:41 u20210427_BB.gz [nir@etl-dev test]$ X=AA,BB [nir@etl-dev test]$ echo $X AA,BB [nir@etl-dev test]$ gunzip *_{${X}}.gz gzip: *_{AA,BB}.gz: No such file or directory [nir@etl-dev test]$ gunzip *_{AA,BB}.gz [nir@etl-dev test]$ ll total 756 -rw-rw-r-- 1 nir nir 249448 May  6 10:35 a20210427_AA -rw-rw-r-- 1 nir nir 249448 May  6 10:36 a20210427_BB -rw-rw-r-- 1 nir nir  22259 May  6 10:35 a20210427_LR.gz -rw-rw-r-- 1 nir nir 249448 May  6 10:41 u20210427_BB  Ideas?


Why does the \foreach command in TikZ give wrong results for step size 0.1?

How come that in the code below, \foreach is unable to give me round numbers?  \documentclass{standalone} \usepackage{tikz} \usepackage{pgfplots}  \usetikzlibrary{positioning, calc}  \begin{document}     \begin{tikzpicture} \foreach\x in {0.1,0.2,...,0.9}\node at (0,{-2*\x}){\tiny\x};     \end{tikzpicture} \end{document}


Kill a process with a specific "Command Line" from command line

Is there a command line utility that kills all processes with a specific command line?  E.g. kill all processes named "java.exe" with a command line that contains "-jar selenium-server.jar". This is possible through process explorer.


Showing that, for $|a|>3$ and $n\geq1$, the function $f(z)=e^z-az^n$ has exactly $n$ roots (all simple and different) in the open unit disc

Let $|a|>3$, $n\geq1$, $n\in\mathbb{N}$,    then the function $$f(z)=e^z-az^n$$    has exactly $n$ roots in the disc $\{z\mid|z|<1\}$, and that they are all simple.      Hint: look at $f(z)-f'(z)$   I am not sure how do I even approach proving existence of roots, rather then proving maybe that the function is not vanishing (and then it has logarithm, and root, but how do I show existence of n roots?)  I thought also of maybe using somehow Rouche's Theorem, since:  $$f(z)-f'(z)=az^{n-1}\cdot(n-z)$$  and from there, that showing that $f$ has $n$ roots in the disk.  Thank you!


Is it appropriate to speak to the reader in scientific paper (but without using "you")?

This is similar to the , but my question is different because I'm not asking about ever using "you" in my writing. I quite like using the turn of phrase "Note that...". For example, I'm discussing some feature of data that reflects a physical property. But then I want so say that my data looks a little different because of such-and-such reasons. So, I would like to write something along the lines of: "Note that all experimental data in this manuscript shows just half of the typical shape because we performed only half of the typical sweep." When I write "Note...", I'm actually speaking to the reader directly. It's kind of like saying, "Hey you! Pay attention here!" Everywhere else in the manuscript the focus is on the experiment and not on the reader. So, would this be frowned upon?


I'm trying to find the top k frequent word in an input string. However, in my test case, it's printing out [Ljava.lang.String;@38af3868 even I tried to use the toString methods. What do I need to do to print out the string output instead of references? I should see strings as {"a","b"} here instead of references. public class TopKFrequentWords {      public static void main(String[] args) {                TopKFrequentWords s = new TopKFrequentWords();                String [] e1 =  {"a", "b", "c", "a", "b"};                String[] res = s.topKFrequent(e1,2);                System.out.print(res.toString()); //is not printing out strings            }                      public String[] topKFrequent(String[] combo, int k) {                 if (combo.length == 0) {                     return new String[0];                 }                 Map<String, Integer> freqMap = getFreqMap(combo);                 PriorityQueue<Map.Entry<String, Integer>> minHeap = new PriorityQueue<>(k,                         new Comparator<Map.Entry<String, Integer>>() {                     public int compare(Map.Entry<String, Integer> e1, Map.Entry<String, Integer> e2) {                         //compareTo compares map e1's fre with e2's freq                         return e1.getValue().compareTo(e2.getValue());                     }                 });                 // .entry set() returns a collection view of the mappings contained in the map                 for (Map.Entry<String, Integer> entry: freqMap.entrySet()) {                     if (minHeap.size() < k) {                         minHeap.offer(entry);                     } else if (entry.getValue() > minHeap.peek().getValue()) {                         minHeap.poll();                         minHeap.offer(entry);                     }                 }                 return freqArray(minHeap);             }                      private Map<String, Integer> getFreqMap(String[] combo) {                 Map<String, Integer> freqMap = new HashMap<>();                 //for s in combo; for i = 0; i< combo.length(), i++                 for (String s: combo) {                     Integer freq = freqMap.get(s);                     if (freq == null) {                         freqMap.put(s,1);                     } else {                         freqMap.put(s, freq + 1);                     }                 }                 return freqMap;             }                      private String[] freqArray(PriorityQueue<Map.Entry<String, Integer>> minHeap) {                 String[] res = new String[minHeap.size()];                 for (int i = 0; i < minHeap.size(); i++) {                     res[i] = minHeap.poll().getKey();                 }                 return res;             }                                      }


Rate limit questioners who consecutively ask closed questions

Often times a user will ask a series of questions that get closed, one right after the other. They will often ask these over the course of the same day, sometimes they'll even ask all 6 of their daily allotment of questions, only to have them closed, one right after the other.   Right now, other than a moderator flag there is little notification that this behavior is ongoing.  Question closure like this is often transparent to a novice user and there is little indication that they need to slow down and stop. Sometimes, the first notice that they receive that something is wrong is a moderator comment, other times it might be a moderator message accompanied by a week long suspension (I've had at least two cases on a site I moderate where this happened).  Users need a more effective braking system that will help them slow down and think about what they are doing.  I propose modifying the existing rate limits on questions/day or questions/month to slow or stop people who ask multiple closed questions in short order.  This solution will ease moderator load by helping the folks who ask these questions to self diagnose what is wrong with them (or get help), and it may overall limit the number of folks who run into question bans on larger sites by slowing the number of questions they can ask and helping them focus on fewer, better questions.  At the very least, it might slow the influx of cruft into larger sites by more quickly limiting the number of questions a user who is having trouble catching on to the system may ask.


Trailing spaces on comment link format preventing it to form a link  [Stack Overflow ](http://stackoverflow.com)   May be by-design or even dup, but just reporting what I accidentally found today.


What did Freeman Dyson mean when he said this?

In this , Freeman Dyson, when speaking of Fermi said the following thing,  "...what does he think about the numerical agreement, and he said, 'How many parameters did you use for the fitting? How many free parameters are there in your method?' So I counted up. It turned out there were four. And he said, 'You know, Johnny von Neumann always used to say, "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk."  My question is that what did he mean when used the word parameter? My guess is that he is talking about the variational parameters in Wave function, but I don't get the idea how that is not allowed to be fair for precise measurements.


It is written in the  paper that the ipad=0x36 and opad=0x5C were chosen such that it maximize the  of the part of the key used in the inner and outer part of the HMAC process.  Since 0x36=0b0110110 and 0x5c=0b1011100, it seems that the Hamming distance is 4, but I would expect that ipad and opad with Hamming distance of 8 would have been used.  Do you know how does those exact ipad and opad values make the scheme stronger?


Derivative of $(y-XB)' h(y-XB)$ with respect to $B$

Let $X$ be a $n\times p$ matrix, $y_{n\times 1}$ a vector and $B_{p\times 1}$ coefficients so that $y=XB$. Then what is the derivative of  $$ (y-XB)' h(y-XB) $$ with respect to B, where $h(.)$ is an $R^n\rightarrow R^n$ differentiable function e.g. ($h(z)=z$) and $(')$ is the transpose of a matrix?


The following are the two main definitions of the verb peruse that the editors at Merriam-Webster.com have put forward:      : to look at or read (something) in an informal or relaxed way      : to examine or read (something) in a very careful way   In my humble opinion, those two acceptations of the said verb contradict each other. Wonder what on Earth is going on here; it's like saying "peruse is A" and "peruse is not A".     Why did the more modern-day definition make it to the top of a  in the Merriam-Webster Dictionary?


How does subsurface scattering RGB radius work? Right now, I have a light source and instead of RGB, it is showing cyan magenta and yellow. I don't know why this is happening and I have read documentation and watched video tutorials and nothing seems to have shown the problem or even properly explain how to use this tool.


How to parse time to String value in android?

I have time value from server returned as 13:00:45:888 which is returned as TIME value from SAP backend . How can I convert it to 01:00 PM


Finding all monic complex polynomials $P(x)$ such that $P(x)|P(x^2)$

Find all monic complex polynomials $P(x)$ such that $P(x)|P(x^2)$.  My progress so far is that I have find that for degree 1, $P(x)=x, x^2$ are the only ones. For degree 2, they are $P(x)=x^2+x+1, x^2, x^2-1, x^2-x, x^2-2x+1$. I also prove that these are only solutions for degree 1 and 2. However I do not see how this generalizes. Any help please?


Integrate $$\int \sin^4x \cos^2x dx$$  Now, there's few solutions to this problem already on the internet. For example on yahoo:  and MIT   I've tried a slightly different approach and simply wonder if my answer is correct as I don't know how to check it.  \begin{eqnarray} \int \sin^4x \cos^2x dx &=& \int \left( \frac{1-\cos^2x}{2} \right)^2 \cos^2x dx \\ &=& \frac{1}{4} \int (1-2\cos^2x+\cos^4x)\cos^2x dx \\ &=&  \frac{1}{4} \int \cos^6x-2\cos^4x+\cos^2xdx \\ &=&  \frac{1}{4} \left( \frac{1}{7}\cos^7x-\frac{2}{5}\cos^5x+\frac{1}{3}\cos^3x \right) + C \end{eqnarray}


A few hours ago I installed the Stack Exchange app to ask a question over at .  When I recieve an answer, I open the app to comment and the app gives me this notification:  You have not joined this site yet, would you like to join?  Cancel Join Now  When I tap Join Now, it does nothing but give me the following error on the status bar: You are already a member on this site.  I've been using Google Chrome since. Please help or fix, Chrome is aggravating me.


Switching power supplies with a relay, how to account for delay between connections?

this is my first post on this site (but I will have more, have no doubt), so if I have posted in the wrong section or something please forgive me.  Anyway, I am currently doing a battery powered pc build and I have wired up a DPDT mechanical relay to automatically switch between a battery and a 12V regulated powersupply. The problem I have run in to is that the amount of time when the relay actually switches over from one pin to the next is too long and it will shut off my dc-dc powersupply for the computer (it is an M4 ATX PSU). My first thought was to try to find a make-before-break relay but those seem scarce and may damage my lithium battery. The other idea that I had was to maybe use a capacitor bank to supply the necessary 20A at 12V for about 10-50 milliseconds, but I have honestly no idea how to find the right size of capacitors for the job. I might have to deal with the shut-down when plugging it in if the capacitor bank is too large because space is tight in the case I'm building.  Thanks for your help, Kevin


Finding number of ways of selecting 6 gloves each of different colour from 18 gloves?

There are nine pairs of gloves each of different colors in how many ways can we select six gloves such that each is of different color? I tried like this : First number of ways in which we can select 6 colors out of nine it is $^9C_6$  ways. Then we can arrange it in 6! ways and also we can select either of two gloves out of the 6 in $2^6$ ways. Hence required number of ways should be $^9C_6$  .$2^6$.6!


Quotation marks in a multi-paragraph quote

When quoting one person in a (long) multi-paragraph monologue (shortened here), should the ending quotation marks for one paragraph be omitted if the next paragraph starts with an attribution tag? I have not been able to find an answer to this anywhere.  "Everyone has to have a flag. <--- Quotation marks here, or not?  After a moment he added, "They were the only ones left."


How can I install pygame on python with cygwin?

I cannot install pygame on cygwin properly. I tried to follow that old doc , , but it doesn't work.  Worse issue is SDL not be able to install correctly  Any helps are welcomed as I've been struggling for days.


How to apply existing javascript on page for appended or replaced html by ajax call

I have display html on page using jquery-ajax call. But javascript on that page not working for html added from jquery-ajax response. I tried "async:false " but this one working for on window load. I want to make it working for Click event as well.  Is there any solution to use existing javascript for appended or replaced html on click event?


I accidentally deleted the Ubuntu partition. All I get now is the grub rescue prompt. I have a Live USB from Ubuntu but I cannot do anything with it. I changed the boot device priority from BIOS but it still won't boot from anything. I have read other similar posts but on most of them, booting from a live usb/cd is suggested.   However, that doesn't work in my case, as described. The ls command first shows something like   (hd0), (hd0,msdos2) , (hd0,msdos3), (hd1), (hd1, msdos1)    and when I try ls on each of them it says unknown file system.


Probability that $m$ balls will fall into first box

Suppose we have $n$ balls that are randomly distributed into $N$ boxes. Find the probability that $m$ balls will fall into the first box. Assume that all $N^m$ arrangements are equally likely.  Attempt: First, we notice that for the first box, we have $n$ choices, and for the second box we also have $n$ choices, and so on. Thus, we have $n^N$ ways to place the balls into the boxes. Pick $m$ balls out of the total $n$ balls, that gives ${n \choose m}$. In how many ways can these $m$ balls go into the first box? Well, in just ${1 \choose 1 }= 1 $ ways. Thus, $$ P = \frac{ {n \choose m } }{n^N } $$ Is this correct?