While I am executing the below code in eclipse:  class Account {   int a, b;   public void setData(int c, int d)   {     a=c;     b=d;   }    public void showData()   {     System.out.println("Value of a: "+a);     System.out.println("Value of b: "+b);   } }  public class ObjectArray  {   public static void main(String args[])   {     Account obj[] = new Account[2];     //obj[0]=new Account();     //obj[1]=new Account();     obj[0].setData(1, 2);     obj[1].setData(3, 4);     System.out.println("For Array Element 0:");     obj[0].showData();     System.out.println("For Array Element 1:");     obj[1].showData();   } }   I am getting an below exception:  Exception in thread "main" java.lang.NullPointerException     at ObjectArray.main(ObjectArray.java:24)  Please give me suggestion why this error has occurred?

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I would like to know how can i securely erase disk on AIX as per DOD standards? any utility i can download and use on aix server  rather using regular dd or diag command? Appreciate your help!  Regards, Adel

I'm looking for a quick, simple, and effective way to erase the hard drives of computers that my company will be getting rid of (donation to charity, most likely). Ideally, I would like a single-purpose bootable utility CD that upon booting, finds all attached hard drives and performs an "NSA grade" disk erasure.  Is anyone aware of such a utility (even one not quite as automated as what I've described)?


I have issues installing mysql,  sudo apt-get update sudo apt-get install mysql-server   I also tried:  sudo dpkg -P mysql-server-5.1 mysql-server sudo apt-get install mysql-server   I get the following error:  Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details. invoke-rc.d: initscript mysql, action "start" failed. ● mysql.service - MySQL Community Server    Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)    Active: activating (auto-restart) (Result: exit-code) since Mon 2017-05-15 14:43:06 CEST; 5ms ago   Process: 22585 ExecStartPost=/usr/share/mysql/mysql-systemd-start post (code=exited, status=0/SUCCESS)   Process: 22584 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE)   Process: 22576 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)  Main PID: 22584 (code=exited, status=1/FAILURE)       CPU: 485ms  maj 15 14:43:06 XPS-13-9350 systemd[1]: mysql.service: Unit entered failed state. maj 15 14:43:06 XPS-13-9350 systemd[1]: mysql.service: Failed with result 'exit-code'. dpkg: error processing package mysql-server-5.7 (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of mysql-server:  mysql-server depends on mysql-server-5.7; however:   Package mysql-server-5.7 is not configured yet.  dpkg: error processing package mysql-server (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                                                                                Processing triggers for systemd (232-21ubuntu3) ... Processing triggers for ureadahead (0.100.0-19) ... Errors were encountered while processing:  mysql-server-5.7  mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1)   If I type mysql I get:  ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)   It seems to have semi-installed as if I do mysql -u root -p I get the password prompt, but nothing happens.  I tried starting it using sudo service mysql start but I got this error message in mysql.service:  $ systemctl status mysql.service  ● mysql.service - MySQL Community Server    Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)    Active: activating (start-post) (Result: exit-code) since Mon 2017-05-15 14:24:24 CEST; 13s ago   Process: 13333 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE)   Process: 13317 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)  Main PID: 13333 (code=exited, status=1/FAILURE); Control PID: 13334 (mysql-systemd-s)     Tasks: 2 (limit: 4915)    Memory: 1.8M       CPU: 353ms    CGroup: /system.slice/mysql.service            └─control              ├─13334 /bin/bash /usr/share/mysql/mysql-systemd-start post              └─13397 sleep 1  maj 15 14:24:24 XPS-13-9350 systemd[1]: Starting MySQL Community Server... maj 15 14:24:26 XPS-13-9350 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE

My overall upgrade went well, but I am left with a critically lingering issue of mysql-server not being able to install itself, and nothing I am trying gets it to work.  This is the error I see when trying to install/reinstall it:  Setting up mysql-server-5.7 (5.7.11-0ubuntu6) ... Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details. invoke-rc.d: initscript mysql, action "start" failed. dpkg: error processing package mysql-server-5.7 (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of mysql-server:  mysql-server depends on mysql-server-5.7; however:   Package mysql-server-5.7 is not configured yet.  dpkg: error processing package mysql-server (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                    Processing triggers for systemd (229-4ubuntu4) ... Processing triggers for ureadahead (0.100.0-19) ... Errors were encountered while processing:  mysql-server-5.7  mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1)   I've tried completely removing it, though doing so attempts to install MariaDB because of dependencies (?). Any suggestions on what I can do to fix this would be most welcome.  EDIT: Looks like I'm not the only one:


It is known that we must need to convert the differential equation in polynomial equation of differential coefficients. But Can we differentiate a differential equation (whose degree is not defined) to determine its order and degree ? Example to show my doubt clearly: $y''=e^{y'}$ Above differential equation has its degree undefined. Differentiating it with respect to $x$ $y'''=(y'')^2$ So we may conclude that this is third order differential equation with degree $=1$ I know that on differentiating a differential equation number of arbitrary constants of solution equation increases hence we should not differentiate a differential equation in general. But I did not found a reference which states that we cannot differentiate a differential equation to determine its order and degree so I want to confirm my thoughts.

Here is a question in my book  Find the order and degree of the differential equation $$y=1+\frac{dy}{dx}+\frac{1}{2!}{\left(\frac{dy}{dx}\right)}^2+\frac{1}{3!}{\left(\frac{dy}{dx}\right)}^3+\cdots$$  At first sight we can conclude that the order is $1$ and the degree is undefined as  as the power of $\frac{dy}{dx}$ continues to increase and has no limit.However  my book gives the following solution  Rewrite the DE as $$y=\exp\left({\frac{dy}{dx}}\right)$$ $$\implies \frac{dy}{dx}=\ln y$$ whose order and degree is 1 .  Now ,I completely agree with this solution however I find it rather counterintuitive to my first line of thought .If the book is correct how can it be justified to prove my intuition was wrong?


Do moderators have the privilege to accept the answer on their own if answer gets much positive points and is helpful for users?

I think it would be cool if a question would eventually open up to moderators to accept answers on the user's behalf, once a time period has passed. The asking user would get the rep score for the accept.  I know I've seen questions successfully answered with lots of upvotes and no accepted answer that sit there for months unaccepted. This would give superusers a little more functionality and would tie up a lot of loose ends.  What do you think?


Is it possible to wrap text in the header of an attribute table in print composer in QGIS 3.x?  There are options for wrapping text in the cells within the body, but they don't seem to work for the headers. Other questions on stack exchange indicate it was not possible in previous versions, but all of the questions/answers are several years old, and there has been significant progress since then.  (This question, for example: ) I'm using version 3.8.3 (Zanzibar)  I've tried both adding \n to the attribute heading, and setting the "wrap text on" box to * and adding that to the header.  Both of these approaches work within the body of the attribute tables.

The "wrap text on" function seems not to work for the heading of the columns, only for the rows.  I'm using QGIS 2.14.4


I understand that the standard deviation corresponds deviance from the mean but does the actual value of the standard deviation have any direct meaning? For example if you have a $\sigma$ of 10, does 10 mean anything by itself? (relative to the problem)

Is there any intuitive way to interpret the standard deviation regardless of the probability distribution?  So for example, for the normal distribution, I know how to interpret being within 1 standard deviation - there is a a 68% of being there. For other distributions I can calculate this probability as well.  But if I don't know the distribution, how is it a meaningful statistic? Is it only meaningful in relation to other random variables that we know follow the same distribution, but have a different standard deviation?


I am trying to add multiple authors but the \\ doesn't work on \name.  I've been given a template to work with \name but I have too many authors and the names don't fit properly. I have 9 authors some of them very long names.  I have the following:   \documentclass{article} \usepackage{spconf,amsmath,graphicx} \usepackage{booktabs}   \begin{document}  \title{Title here}   \name{AuthorName1,AuthorName2,AuthorName3,AuthorName4,Authorname5,AuthorName6,AuthorName7, AuthorName8, AuthorName9} \address {Address 1 \\  Address 2 \\ Address 3} \maketitle  \end{document}   Can anyone help how to put the authors names in two rows?

I'm currently entering authors an a paper and I came across this problem:    As you can see there are multiple names on one line, though outside the page. I would like to get them on two lines. At the moment I'm using the \name tag. I tried separating the lines the sentence by adding two backslashes, but it did not help. (I get "! Missing } inserted." error.) I tried replacing the \name tag by \author, but it did not work.   Example:  \documentclass{article}  \usepackage{spconf,amsmath,graphicx} \usepackage{amsmath}  \usepackage{algorithm}  \usepackage{algpseudocode}  \usepackage{color} \usepackage{cite}   \title{Title}    \name{Name1$^{1}$, Name2$^{3}$, name3$^{3}$ name4 $^{1,2}$, name5,$^{2}$ name6 $^{2}$, name7$^{3}$}   %  \maketitle  %   \begin{abstract}   I tried:   \name{Name1$^{1}$, Name2$^{3}$, name3$^{3}$ name4\\ $^{1,2}$, name5,$^{2}$ name6 $^{2}$, name7$^{3}$}   But I get an error.


I am currently deploying computers in my client's house.   I am running the following scripts:    ngrok (an ssh forward tunneling daemon) heartbeat.py (a script which sends a heartbeat signal to loggly which confirms my computer is alive) metrics.py (a script which logs all the environmental data such as temp, disk space to loggly)   So in my tests so far, metrics.py is somewhat unstable (meaning it crashes occasionally).   Is there a package in *NIX which does the following?     check every X second on whether a process is running if #1 is not true, run it Do this for a list of process

Can I make a bash command line that only runs a certain command if the process is not already running (in the background)?  How do I check*, if a command is already running?  (so I can add the next command with && in between them so the next one only executes if the first one is true).  *: test, determine, discover, find out


The formula above is the equation for acceleration due to gravity when earth rotates. G is the original acceleration.  Can someone explain how this formula came?

I have this problem:     If the constant of gravity is measured to be $g_0$ in an earth fixed   coordinate system, what is the difference $g-g_0$ where $g$ is the   real constant of gravity as measured when the earth stands still.   The earth fixed coordinate system is rotating, so that the absolute acceleration $g$ is given by  $g=g_0+2\vec\omega\times\frac{d}{dt}\vec r+\vec\omega\times (\vec \omega\times \vec r)$  This is the Coriolis term and the Centrifugal term, the other ones disappear since earth rotates in a steady pace and does not itself accelerate.  I know the answer is supposed to be  $g-g_0\approx g_0\frac{x^2-2x}{2}\cos^2(\phi)$  Where $x=\frac{R \omega^2}{g_0}$. How can I come to this conclusion? My attempts so far have been to try to evaluate the expression given earlier. But I cannot for my life figure out how that yields the supposed answer.  (Note: I've edited the "correct" answer, multiplying what was written originally with g_0 after  some of the answers were written)


I have an equation long enough to occupy two lines. I want to break it to improve readability. How can I break it?  \begin{equation} F = \{F_{x} \in  F_{c} : (|S| > |C|) \cap  (minPixels  < |S| < maxPixels) \cap  (|S_{connected}| > |S| - \epsilon)   \} \end{equation}   I want to break it in 3 lines after \cap. But \\ or \n didn't work.

I am having the following equation:  \begin{equation}   Q(\lambda,\hat{\lambda}) = -\frac{1}{2} P(O \mid \lambda ) \sum_s \sum_m \sum_t \gamma_m^{(s)} (t) \left( n \log(2 \pi ) + \log \left| C_m^{(s)} \right| + \left( \mathbf{o}_t - \hat{\mu}_m^{(s)} \right) ^T C_m^{(s)-1} \left(\mathbf{o}_t - \hat{\mu}_m^{(s)}\right) \right) \end{equation}   which does not very well fit on one line. How can I split this over two lines? What I have in mind is that I specify the splitting place, and that the first line is left aligned and the second line right aligned to make clear that it is still the same equation.  The linebreak \\ does not work.


My 1 TB system disk (C:) is getting really full, and this is due to lots of pics and videos in my User folders.  All this is being stored on C:, but I have just installed a new 2 TB hard drive, and I would like to have Windows move all this stuff to the new drive (K:).  I know I can't just highlight, cut and paste, but how is this supposed to be done?

Let's say I have Windows installed on drive C, however I install all of my programs on the D drive, and I keep my user profile on the D drive as well (things like My Documents). How can I have Windows use those folders instead of the ones on the C drive?


Is there any way of limiting the displayed repeat values in one page?  Ex: Display first two values in first page, next two values in the next page etc ?   I tried to find a way of doing this but I could not find anything helpful.

I have the following VF page, but when I render it as pdf the Apex:repeat tables break in the middle to the next page. I'm thinking of limiting the tables displayed in each page to avoid table breaks. Is there any way of doing this or any better ideas ? Any help on this would be appreciated.            <apex:outputPanel layout="none" >             <apex:repeat value="{!rsReportRows}" var="reportRow" >

                         Risk

                         <apex:repeat value="{!parentObj.fieldLabelsList}" var="fieldLabel" >                             <apex:outputText value="{!fieldLabel}" />	                         </apex:repeat>

                         <apex:repeat value="{!parentObj.fieldApiNamesList}" var="field" >                                                              <apex:outputField value="{!reportRow.risk[field]}" rendered="{!field != 'risk__residual_score_movement_direction__c'}" />                                 <apex:outputField value="{!reportRow.risk[field]}" rendered="{!field == 'risk__residual_score_movement_direction__c' && (CONTAINS(reportRow.risk[field],'Up') || CONTAINS(reportRow.risk[field],'Down') || CONTAINS(reportRow.risk[field],'Right'))}" />                             	                         </apex:repeat>

                                   <apex:repeat value="{!relatedList}" var="rList" >                     <apex:outputPanel layout="none" rendered="{!rList.isSelected && rList.fieldsList.fieldApiNamesList.size > 0}" >

                                 {!rList.relationshipLabel}

                                 <apex:repeat value="{!rList.fieldsList.fieldLabelsList}" var="fieldLabel" >                                     <apex:outputText value="{!fieldLabel}" />	                                 </apex:repeat>
                              <apex:repeat value="{!reportRow.objRecords[rList.relationshipName]}" var="record" >
                                     <apex:repeat value="{!rList.fieldsList.fieldApiNamesList}" var="field" >                                                                                <apex:outputField value="{!record[field]}" />                                         	                                     </apex:repeat>
                             </apex:repeat>
                     </apex:outputPanel>                 </apex:repeat>
&nbsp;

&nbsp;
             </apex:repeat>         </apex:outputPanel>


What do you do?  Is it natural to be upset when you ask a question in the spirit of learning and people vote you down?

I've posted a question or an answer, and I have received one or more downvotes. I am not really sure why I was down voted, or I think I know why, but I disagree.  Why did this happen, and what should I do about it?


There is  on the home page.  How does Stack Overflow define what is interesting to me?

According to the tooltip of the 'interesting' tab, interesting questions are     "questions that may be of interest to you based on your history and tag preferences"   Does Stack Overflow use a recommendation engine or just some sql sort/filter?


What is the remainder when $2^{2018}$ is divided by $43$?  I know that this has something to do with one of Fermat's Theorems. I am almost at a loss as to how to solve for the remainder or why it has anything to do with Fermat's Theorem  Here is Fermat's Theorem:   If $p$ is prime and $a$ is not divisible by $p$, then  $$a^{p-1}\equiv 1( \text{mod }p)$$ If $a$ is divisible by $p$, then $$a^{p}\equiv a(\text{mod } p) $$

How do I efficiently compute $a^b\bmod c$:  When $b$ is huge, for instance $5^{844325}\bmod 21$? When $b$ is less than $c$ but it would still be a lot of work to multiply $a$ by itself $b$ times, for instance $5^{69}\bmod 101$? When $(a,c)\ne1$, for instance $6^{103}\bmod 14$?  Are there any other tricks for evaluating exponents in modular arithmetic?  This is being asked in an effort to cut down on duplicates, see  and .


I have installed sublime text 3 using official website . I can launch it from searching and clicking on sublime icon as well as from terminal just by typing subl. But nothing is working when I type   > sudo subl [some file name]   No error nothing is being displayed. How to resolve this? I have ubuntu 17.10  I am trying   > gksudo subl ~/.bashrc  Unable to copy user's Xauthrisation file

I installed Ubuntu 17.10. Now I am having trouble with gksu:  $ gksu -dg synaptic No ask_pass set, using default! xauth: /tmp/libgksu-HgUjgQ/.Xauthority STARTUP_ID: gksu/synaptic/8760-0-alex-XPS-15-9530_TIME4974977 cmd[0]: /usr/bin/sudo cmd[1]: -H cmd[2]: -S cmd[3]: -p cmd[4]: GNOME_SUDO_PASS cmd[5]: -u cmd[6]: root cmd[7]: -- cmd[8]: synaptic buffer: -GNOME_SUDO_PASS- brute force GNOME_SUDO_PASS ended... Yeah, we're in... Unable to init server: Could not connect: Connection refused (synaptic:8767): Gtk-WARNING **: cannot open display: :1 xauth: /tmp/libgksu-HgUjgQ/.Xauthority xauth_env: (null) dir: /tmp/libgksu-HgUjgQ   If I don't use -g, the password dialog is disabled. So looks like a problem with creating a tty for root.  Any advice?


I'm using java on Eclipse     Servlet.service() for servlet [ecarssServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause   at kr.co.ECarSS.www.carmin.service.CarDevServiceImpl.carDevExcelRegister(CarDevServiceImpl.java:118)   SO   String terDes = "유심:" + excelData.get("일반유심").toString().replace(" ", ""); terDes += ", S/N:" + excelData.get("모뎀S/N").toString().replace(" ", "");                 terDes += ", " + excelData.get("턴키").toString().replace(" ", "");                 terDes += " 개통일자:" + excelData.get("개통일자").toString().replace("-", ".");                 insertData.put("terDes", terDes);    how to solve this problem   or how to use if(excelData.containsKey)

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


Prove that $2^{n} < n!$ $\forall$ n > 4   $n=5:$ $$2^{5}<5!$$  $$32 < 120$$  This is true.  Now, after knowing it worked for $n$ we need to show it works for every other, so $n+1$:  $$2^{n+1} < (n+1)!$$  $$2^{n} < \frac{(n+1)!}{2}$$   We know from beginning that $2^{n} < n!$  So we replace it with it here and then show:  $$n! < \frac{(n+1)!}{2}$$  $$n! < \frac{n!\cdot(n+1)}{2}$$  $$1<\frac{n+1}{2}$$  Task say for all $n > 4$ so the thing on the right side will really be greater than $1$.    I hope everything is ok?  Edit: The possible-duplicate-link didn't help me because I'm not really looking for a solution to the task. I'm rather interested in knowing if MY proof is correct.

I'm told to show that $2^n < n!$ using induction  This is my attempt at it:  BC: $n=4, 2^4 = 16 < 4!$  IH: n = k, $2^k < k!$  IS: try n = k+1  I'm told to only work from one side, so I try the left side:  2^(k+1)   But I'm stuck here, any ideas?


I have a very nearly fresh 16.04 installation (only installed a couple of weeks ago). Today, when I try to  $ sudo apt update $ sudo apt install openssh-server   I'm greeted with  The following NEW packages will be installed   ncurses-term openssh-server openssh-sftp-server ssh-import-id 0 to upgrade, 4 to newly install, 0 to remove and 2 not to upgrade. Need to get 373 kB/633 kB of archives. After this operation, 5,136 kB of additional disk space will be used. Do you want to continue? [Y/n] Y Err:1 http://gb.archive.ubuntu.com/ubuntu xenial-updates/main amd64 openssh-sftp-server amd64 1:7.2p2-4ubuntu2.5   404  Not Found [IP: 91.189.88.152 80] Err:2 http://gb.archive.ubuntu.com/ubuntu xenial-updates/main amd64 openssh-server amd64 1:7.2p2-4ubuntu2.5   404  Not Found [IP: 91.189.88.152 80] E: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/pool/main/o/openssh/openssh-sftp-server_7.2p2-4ubuntu2.5_amd64.deb  404  Not Found [IP: 91.189.88.152 80]  E: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/pool/main/o/openssh/openssh-server_7.2p2-4ubuntu2.5_amd64.deb  404  Not Found [IP: 91.189.88.152 80]  E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?   So obviously, I tried sudo apt update --fix-missing, which changed nothing.  Clearly, either my system is looking for a version of the package that no longer exists, or some server administrator deleted something they shouldn't have. My money's on the former.  Does anybody have any idea how I might debug or fix this problem? I'd like to tackle the root cause, rather than just have a workaround for openssh.  The one relevant difference on my system, which may affect things, is that I have an NVIDIA SDK installed which, amongst other things, adds arm64 architecture to apt so it can download some packages for cross-compilation. I'm using an amd64 (not arm64) system. This means that when I apt update, I get a bunch of errors relating to repositories that don't carry arm64 pacakges, like this:  E: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/xenial/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.162 80]   This isn't a problem (and I believe is a necessary evil of working with this SDK). I only mention it because it might have a bearing on my current issue.    Edit:  The root cause of the problem is , but the problem itself is different.

W: Invalid 'Date' entry in Release file /var/lib/apt/lists/_var_cuda-repo-8-0-local_Release N: Skipping acquire of configured file 'non-free/binary-arm64/Packages' as repository 'http://repository.spotify.com stable InRelease' doesn't support architecture 'arm64' E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-updates/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-backports/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-security/main/binary-arm64/Packages  404  Not Found [IP: 91.189.88.161 80] E: Some index files failed to download. They have been ignored, or old ones used instead.   After I installed Jetpack for Jetson tx1, my ubuntu constantly tries to fetch arm updates. Is there a way to disable this?  EDIT:   $dpkg --print-architecture amd64  $dpkg --print-foreign-architectures i386 arm64   I see that arm64 is included in foreign architectures. How do I remove it?


LaTeX won't let me use _ in my text, it keeps trying to compile it as math and therefore won't compile my pdf.  Anyone knows how I can make it not do that?  I'm using it in the following:  \textit{item_name} \textit{current_item.name} \textit{_qty} \textit{id='small_qty'}

How can I produce the text Word_one_two in LaTeX?  I tried:  Samp\_Dist\_Corr   But, it doesn't quite look right. Also, I want it in the typewriter font, so actually, I'm doing:  \texttt{Samp\_Dist\_Corr}   I find it looks a bit like the underscore is merging in to the bottom of the "D", but maybe it's just because of the typewriter D?


I'm trying to implement the cost function to estimate the SVM models I've trained with scikit-learn for a classification problem.  Unfortunately, from my course (Andrew Ng's Coursera course on Machine Learning), I have not understood whether the cost function should use 10-based logarithm, or the natural logarithm.  Here's the formula:   Could I use both logarithm functions? Does it have any influence? Which is more appropriate in general?

I'm studying statistics and often come across formulae containing the log and I'm always confused if I should interpret that as the standard meaning of log, i.e. base 10, or if in statistics the symbol log  is generally assumed to be the natural log ln.  In particular I'm studying the  as an example, but my question is more of general one.


I came across :  #!/bin/sh qemu-system-x86_64 -enable-kvm \                    -m 2G \                    -device virtio-vga,virgl=on \                    -drive file=/home/empty/qemubl/lab.img,format=raw,if=virtio \                    -cpu host \                    -smp 4 \                    -soundhw sb16,es1370 \                    "$@"   What is the role of $@?  I searched man bash for $@ but got Pattern not found.

I know these are few special variables used by bash. But I am not able to understand them. Can anyone explain what these variables are and how to use them?  $*  $@  $#


I have a multiple-entry Schengen visa issued by France. I applied for that visa because I was planning to attend a meeting in France, which was postponed, so this visa is unused. I am planning a trip to Italy next week.    Will face any problems since I never used that visa for France?    I am still planning to use it for France and that trip will be longer than my planned trip to Italy.  In this case, is it a good idea to bring a paper showing that the event has been postponed, and that I already bought my plane ticket back from Italy?  Side note: I am not planning to continue my trip to France after going to Italy, so this is not a first entry point question (I know that first entry can be different from the country that issued the visa); there will be two separate trips.

In case, if I get a multiple-entry Schengen visa in one of the embassies in Ukraine, Kyiv - should my first trip be to the country which issued the visa?  Any there any requirements of this sort? Does this condition vary depending on embassy which issued the visa?  What are the possible consequences on not visiting that country first? Does it somehow depend on country where the embassy is (i.e. non-Schengen and not EU members)?


Please help me understand the following concept. Let A be a matrix of constants and Y is a random vector. Var(AY) = AVar(Y)A', where A' is A transpose. I understand that AA' = A^2. What I don't understand is why A' goes in the end, instead of AA'Var(Y). Is there some kind of property in linear algebra that would help me understand the correct order? Thank you!

$\newcommand{\Var}{\operatorname{Var}}$In this  is claimed that if the equation of errors in OLS is given by: $$u=y - X\beta$$ Then in the presence of heteroscedasticity the variance of $u$, will not be constant, $\sigma^2 \times I$, where $I$ is an identity matrix, but: $$\Var(u\mid X)=\sigma^2\Omega$$ In order to account for the heteroskedasticity, we can estimate the transform system, such that $P$ is a transformation matrix. $$Py=PX\beta-Pu$$ Where "the variance of a constant matrix $P$ times a random vector $u$" is: $$\Var(Pu\mid X)=P\Var(u\mid X)P'=P(\sigma^2\Omega)P'$$ Can somebody explain me the proof for that?


In a situation were a rogue uses help as action, disengage as bonus action and movement to move away, does he still help another PC to attack the target with adv?

If, say, a Fighter is engaged in melee with an orc, can the Cleric, starting 10' away from the Orc, move 5' toward the orc, Help the Fighter (to give him Advantage), then move away 25'? He would provoke an attack of opportunity, but would the Help action still work?   Put another way, do you have to be within 5' of the target when the Helped friendly creature attacks in order for it to gain Advantage, or only during your (Help) action?


I'm currently setting up a database to house records for an application I'm writing and am trying to come up with the most efficient DB structure to use... Of course I know that there are as many answers to this as there are people with opinions, but there has to be some kind of logic as to what to do for different situations.  So, as a simple example of my situation. Suppose I was creating the DB in, say SQL Server, to store data about people. Currently there are is a set of, say, 100 characteristics I am storing per person (Some static such as, say, name, sex, etc - Some RELATIVELY static such as age, address, height - and some variable, sich as, say, weight, last_worn_pice_of_clothing... whatever) and I also want the architecture to be flexible enough to be able to accommodate any future characteristics that may come about (this won't happen "too often", but will happen).  So, my logic is that I could go with one of the following storage ideas:  (1)  People_Chars_Table:  Person_Id:    RunDate:    Name: ...<all the other chars> ... Char100: 1             2014-01-01  John Johnson ....                  Val100   In other words, store all the characteristics in a very wide table and every time I have a new characteristic to add, I simply add on a new column.    (2)  Person_Table:  Person_Id:   Characteristic_Table:  Char_Id:    Char_Name:    Char_ValueType: 1           Name          String 2           Age           Integer ....   People_Table:  Person_Id:    RunDate:     Char_Id:     Char_Value: 1             2014-01-01   1            John Johnson 1             2014-01-01   2            23 ....     What (2) seems to allow for is for characteristics to be added very quickly and easily, but it seems like querying out the data will always involve some kind of pivot operation that might slow things down (The 2 things that might also be important to know, by the way, is that this data will be queried fairly often and that the table would have about 100000 new people records added monthly - each with about 100-150 characteristics).  And, then, of course, there is a hybrid option of the person table having some of the pre-set characteristics and then using the rest from option (2).  Overall, I'm just wondering if there is any logic about what is the best practice or, aside from these 2 options I'm seeing, is there another way of handling this completely?  Any advice would be greatly appreciated!!! Thanks!!!

For application, which has few (5-10) settings at the moment but will have a lot more (up to 100) in the future which would be better approach:   to add new columns to settings table every time new setting is introduced to have settings table as key/value storage   Consider that application might have millions of instances (which all run on the same db and use the same table for settings), DB might be sharded. DB is relational, i.e. either MySQL or T-SQL.  As a developer I would prefer the 2nd variant, so I could scale the application without changing the DB schema and add/remove settings at will. As far as I understand having several million records in a single table shouldn't be an issue if the index is clustered on application instance. Are there any drawbacks that I'm not aware of?  And what about 1st variant? Are there any big benefits? And what about the number of columns: is there any theoretical limit of columns that table can have? What happened if I had a table with 1000 (10 000, 1000 000) columns? Would that be slow?


Prove that $Gl_n(\mathbb R)$ and $Gl_m(R)$ are homeomorphic iff $n=m$   Since $Gl_n(\mathbb R)$ is homeomorphic to an open subset of $\mathbb R^{n^2}$, this boils down to proving that two open subsets of $\mathbb R^n$ and $\mathbb R^m$ are homeomorphic iff $n=m$.  This can be done via homology, of which I know absolutely nothing.  Do you know a proof that doesn't cover things an undergraduate isn't supposed to know ?  EDIT: I'll close the question, since it's a duplicate of

It is very elementary to show that $\mathbb{R}$ isn't homeomorphic to $\mathbb{R}^m$ for $m>1$: subtract a point and use the fact that connectedness is a homeomorphism invariant.  Along similar lines, you can show that $\mathbb{R^2}$ isn't homeomorphic to $\mathbb{R}^m$ for $m>2$ by subtracting a point and checking if the resulting space is simply connected. Still straightforward, but a good deal less elementary.  However, the general result that $\mathbb{R^n}$ isn't homeomorphic to $\mathbb{R^m}$ for $n\neq m$, though intuitively obvious, is usually proved using sophisticated results from algebraic topology, such as invariance of domain or extensions of the Jordan curve theorem.  Is there a more elementary proof of this fact? If not, is there intuition for why a proof is so difficult?


I am using JQuery's DatePicker API to select value from text box.  Here is call to DatePicker  $(".datefield").datepicker({                 changeMonth: true,                 changeYear: true,                 dateFormat: 'dd-M-yy'             });   and I am also using jQuery.Validate to validate user input as below  $("#form_assetDetails").validate({                  // Specify the validation rules                 rules: {                     Make: { required: true, maxlength: 30 },                     ModelName: { required: true, maxlength: 30 },                     WarrantyDetail: { required: true, maxlength: 100 },                     Capacity: { maxlength: 90 },                     WarrantyEndDate: { required: true, date: true },                     Quantity: { required: true, number: true, range: [1, 999] },                     PurchaseOrderNumber: { required: true, maxlength: 20 },                     InvoiceNumber: { required: true, maxlength: 20 },                     InvoiceDate: { required: true, date: true },                     AdvanceAmount: { required: false, number: true, range: [0, 9999999] },                     FinalAmount: { required: true, number: true, range: [0, 9999999] }                 },                  // Specify the validation error messages                 messages: {                     //Make: "Please enter asset make"                 },                  submitHandler: function (form) {                     form.submit();                 }             });   for those control that are meant to take date as input, every validation works fine in chrome but when it comes to IE11, it always fails validation.   I tried different format i.e dd/mm/yyyy and it works but why it does not work with current format?

How can I specify a custom date formate to be validated with the  for jQuery?


When I use the cone in the background as a particle instance object on the plane, it is rotated, as you can see. How do I get it to not do that, or rather, how do I get the cones to stand upright on the plane?  There are no rotation transformations still unapplied, I also didn't change anything in the Particle settings (other than "Hair -> Render: Object -> Object:Cone), this is just everything out-of-the-box.

So I have a plane and leaf which I used as a hair particle. But the leaf is passing through the plane. What should I do?   Enabling or disabling rotation doesn't change anything.    These are the leaves used as collection     No rigid body or collision is set up since I don't know how to set that up. The leaves are stationary and no animation is made with the leaves...


Can anyone guide me on how to set up my x86_64 Ubuntu 13.10 for building armhf libraries and executables ?  I have already  installed g++-4.8-arm-linux-gnueabihf, gcc-4.8-arm-linux-gnueabihf and pkg-config-arm-linux-gnueabihf.  And this allowed me to get the compilers (/usr/bin/arm-linux-gnueabihf-g++-4.8 and /usr/bin/arm-linux-gnueabihf-gcc-4.8 ) for building stuff, but now I want to set up the system in order to install the libraries that I need with the dependencies (like uuid-dev:armhf for example).  So I run dpkg --add-architecture armhf and I modify the source lists and update, like so:  deb [arch=amd64] http://fr.archive.ubuntu.com/ubuntu/ saucy main restricted  deb [arch=armhf] http://ports.ubuntu.com/ubuntu-ports saucy main restricted  apt-get update  But when I try to install uuid-dev:armhf, I have unmet dependencies, and I don't know how to solve the problem.  The following packages have unmet dependencies: uuid-dev:armhf : Depends: libc6-dev:armhf but it is not going to be installed or libc-dev:armhf Depends: libuuid1:armhf (= 2.20.1-5.1ubuntu9) but it is not going to be installed

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


After trying to manually set the "app settings" on my new S6 the same as my S3: I realize it will take me hours.  Is there really no way to transfer all old app settings from my S3 to the newly installed apps of my S6?  Helium needs a PC and others need root on both phones.  Any suggestions?

I would like to migrate apps and their data from one phone to another without too much faffing around, like:   rooting (very convoluted device specific process with a lot of ambiguity around it and often involving running closed source software from random vendors that you have to believe does the right thing), using app specific backup export/import facilities if at all exist (too manual, seems the only option though).   I am ok with:   using a PC to help facilitate the process, manual copying/pasting files (within reason).   Ideally, I would like to have a process that works something like this:   select apps that I would like to have in their current state on the other phone, bundle them together and store somewhere (external SD card or PC), put that bundle on the other phone and somehow install and recover their state.   A bit like  works.  So far I have tried :    - unfortunately, like many others, requires rooting,  - seemed promising but Helium has never been, nor ever will be, compatible with any device running anything less than Android 4.0 and it does not work on certain phones.  - Q: Does it backup data of apps? A: No, currently it only backup the apk files of apps. and skimmed through a number of articles including  (looks like even if I was willing to root I would have a hard time).


I have a file (see below), and I would like to count the number of 1's and of 0's:  1 1 1 0 0 1 1 0 0 0 ...   I tried  to use awk but it doesn't work, for example, to count the number of 1's:  awk -F "1\n" '{print NF-1}'   How shall I do it?  I assume the file only contains 1's and 0's, and each line is just a single number. But I more like to know how to generalize to the case for counting the occurrences of a specific line in a file.

I have Apache logfile, access.log, how to count number of line occurrence in that file? for example the result of cut -f 7 -d ' ' | cut -d '?' -f 1 | tr '[:upper:]' '[:lower:]' is  a.php b.php a.php c.php d.php b.php a.php   the result that I want is:  3 a.php 2 b.php 1 d.php # order doesn't matter 1 c.php


$G$ is an abelian group, with $|G| \in \mathbb N, a \in G$, show that $a^{|G|} = 1$.  I have managed to show it using the Lagrange theorem, but I have not used the fact that $G$ is abelian. I am wondering whether the statement is true also for non-abelian groups, or I have made a mistake in my proof.  Sketch of the proof  1) Show that $\exists q \in \mathbb N, q \le |G|$ such that $a^q = 1$ and $\forall n \in \mathbb N, n<q, a^n \ne 1$.  2) Show that $G_a : = \{a^m : m \in \mathbb N\}$ is a subgroup of $G$ and $|G_a|=q$.  3) Directly applying the Lagrange theorem show that $|G|=k|G_a|=kq, k \in \mathbb N_0$.  4) Now it follows that $a^{kq}=1$.

From A Classical Introduction to Modern Number Theory by Ireland and Rosen, page 33:     Corollary 1 (Euler's Theorem). If $(a,m) = 1$, then $a^{\phi(m)} \equiv 1\,(m)$.      Proof. The units in $\mathbb{Z}/m\mathbb{Z}$ form a group of order $\phi(m)$. If $(a,m) = 1$, $\bar{a}$ is a unit. Thus $\bar{a}^{\phi(m)} = \bar{1}$ or $a^{\phi(m)} \equiv 1\,(m)$.   If I'm interpreting this correctly, this proof implicitly uses the fact(?) that if $G$ is a group and $x\in G$, then $x^{|G|}=1$, where $1$ is the identity element of $G$.  If this is indeed true, can someone explain why? (I have had no prior exposure to group theory.)


Every time I login using my Yahoo account, my profile is automatically updated to include my email ID and Real Name from my Yahoo Account. I find this disconcerting and irritating, as I do not wish to share any data through my profile with the public include this data in my profile, if I don't have to.   Yes, I know that every time I login through Yahoo, I get a warning that my name and email will be shared with SE. However, I don't expect SE to automatically add this to my profile when I keep deleting it.  Is there an option to turn this off somewhere? Or do I need to migrate my account?   If not, Feature Request: SE shouldn't play with its users profile and add / delete / update data, especially without warning the user.    Added: My point is that I do not want any data added to the profile unless I have personally included it. Apart from the fact that the name associated with my Yahoo account is not my real name, it is irritating that I have to keep checking my profile to see if SE has "meddled" with it in nay way!    The issue here is of privacy. Sure, the current policy is that you may not display this data publicly now. But what if you pull a Google and decide that you will?    Clarification on the 'Privacy' aspect:  Yes, I know the terms I agreed to, and I am fine with it. But all of you seem to be in a hurry with the "duplicate question" and the down-votes, without actually trying to understand the issues:   The data associated with my Yahoo account automatically being added to the profile. The ambiguity of data collection and handling, that creates false expectation of privacy, by the SE user interface for profile editing.   Details - As stated earlier, my Yahoo account doesn't have my real name. So adding this in the profile automatically, even if it is for SE reference only, doesn't make sense. If you need to "prevent abuse" or for other legal use, isn't it better to just log the Yahoo / Google account data separately rather than adding it to the profile where the user can remove it??   Which brings me to the second point - a false expectation of privacy is created here by allowing users to delete the name and email ID, if you are automatically going to add it every time!   (Example - Google / Yahoo / Microsoft (GYM) enhanced their profiling ability by simply removing the "sign-out / logout" link and moving it to a drop-down menu. This confused users so much that they simply closed the browsers without logging out which enabled GYM to profile them more effectively!)  Stop thinking of this only from a technical perspective of open ID's or oAuth's.   The point here is not that the data is being collected by SE. If SE requires a user's name and email ID, sure, I will give it to you. The thing is that the SE UI is being ambiguous on communicating this to the user. It appears disingenuous if you allow a user to delete info, and then keep adding it automatically without informing the user. Why allow a user to delete the info - in effect indirectly conveying to him / her that the data isn't necessary / required - if you want it in the first place?  Perhaps my feature request should be stated as -      Maintain a distinction between 'account information' and 'user profile' to remove any ambiguity or confusion on the personal data collected and its use.   SE may edit a "user account" information (and intimate the user of the changes), but shouldn't edit a users "profile".

It seems that I'm unable to persistently remove my email address from my profile pages.  Initially removing my email address works fine, I simply visit my profile page on any site associated with my account, edit my email and press the Save And Copy Profile To All Stack Exchange Accounts button. So far, so good.  However, if I'm logged out; whether logging out manually or visiting the site from a new device; I then log into any of my sites using the Stack Exchange method and the following happens:   For the profile page on that site, the email field is automatically re-populated.  For the profile page on subsequently visited sites, I'm automatically logged in but the email field remains empty. I have tested logging into each of the sites and it's only ever the first site that I log into where the profile pages get repopulated with my email address.   Is this expected behavior of Stack Exchange sites or a bug?  Other things to note:   I assume that the email address field on the profile pages are not mandatory. The email address that is repopulated is one I use to log in with the Stack Exchange method. My motives in trying isn't out of email privacy but simply bafflement. I'm aware that .


I am trying to learn how to implement featured snippets and sitelinks but they sent me on this link  but this is pretty old and they only say how you can achieve.but i wanted to ask how could i do it quickly

My website used to have sitelinks and now it doesn't. It's very possible that it's due to changing the website to a sidebar design instead of having an "interstitial" type landing page which limited the number of choices, but I'm not sure.  Here is how sitelinks might look for a site:    What are some things that I can do to improve my chances of getting sitelinks?


I am a relatively recent graphic design graduate. I have been working at a small printing house for about two years, but will soon be interviewing for a different position in another city.  My question is about what to include in my design portfolio. When I was in school, my professors all insisted that work included in a portfolio should be 100% original: my original photography, my original logos, my original layout, my original written content etc. However, at my current office, we rely heavily on client-supplied logos, type content, and photography—and stock photography (shutterstock, etc).  What do other designers include in their portfolios? Has anyone else had this issue and can I reasonable include these more recent projects in my portfolio if I label them appropriately (something like "layout design")?

What is a portfolio, and what should it consist of? Please include details such as the format, use of, number of items, types of items, etc.


You conjure an extradimensional dwelling in range that lasts for the duration   Does this extradimensional space count as a separate plane for effects dependent on the plane a player is on.  For example, take  .     [...] if the target is on a different plane than you, there is a 5 percent chance that the message doesn't arrive.   What about the various planar effects outlined in the Dungeon Master's Guide?  (DMG p. 47)     Creatures on the Astral Plane don't age or suffer from hunger or thirst   (DMG p.61)     As an action, a creature on Limbo can make an Intelligence check to mentally move an object on the plane that it can see within 30 feet of it.

In particular: the  spell (PHB, p. 281) states:  [...] The creature can be anywhere on the same plane of existence as you. The spell ends if you or the target are no longer on the same plane. [...]  Can telepathy connect two characters, one inside the extradimensional dwelling created by the  spell and the other in the same plane as the portal to the magnificent mansion?


This is the code for an archive page on my website, when I try to open this page, it brings up a 404 error and doesn't display any content. Is there a problem in this code that is stopping it? I am using the Custom Post Types plugin for the archive content.  <?php get_header(); ?>      <?php // IMAGE SLIDESHOW ?>

    <img style="width:100%;border:8px solid #91B49C; margin:1em 0 1em 0;" src="<?php echo get_site_url(); ?>/wp-content/uploads/2016/05/Wedding-1.jpg">   <img style="width:100%;border:8px solid #91B49C; margin:1em 0 1em 0;" src="<?php echo get_site_url(); ?>/wp-content/uploads/2016/05/Wedding-2.jpg">   <img style="width:100%;border:8px solid #91B49C; margin:1em 0 1em 0;" src="<?php echo get_site_url(); ?>/wp-content/uploads/2016/05/Funeral-5.jpg">

 <?php // END OF IMAGE SLIDESHOW ?>

Birthday & Anniversary

             <?php $loop = new WP_Query( array( 'post_type' => 'birthdays', 'order' => 'ASC', 'posts_per_page' => -1 ) ); ?>     <?php while ( $loop->have_posts() ) : $loop->the_post(); ?>         <div class="b33" style=" margin:0.5em 0.5em 0.5em 0.5em; border: 8px solid #91B49C; height:350px; width:31.5%; float:left; background-size: cover; background-repeat: no-repeat; overflow:hidden;  background-image: url('<?php the_field( 'image' ); ?>')">
      <?php endwhile; wp_reset_query(); ?>

    <?php get_footer(); ?>

I'm developing a Custom Post Type plugin, which works fine in dev. Now that I've moved it to production, I'm getting a 404 when I try to display the template for the CPT.   So, two questions:  1- Is there some mechanism to determine the path WP took to get through the hierarchy?  2- Why wouldn't it just give me the single or index page?  I've dumped $wp_query and a stacktrace at the end of the 404. Here's part of what I found:  [query] => Array     (         [page] =>          [pagename] => refletters/proximity     )  [request] => SELECT   wp_posts.* FROM wp_posts  WHERE 1=1  AND (wp_posts.ID = '0') AND wp_posts.post_type = 'page'  ORDER BY wp_posts.post_date DESC  [posts] => Array     (     )  [queried_object] =>  [queried_object_id] => 0   And the stack trace:  2013-04-27 22:16:41 - 24.52.197.40 - TRACE - index.php - 404.php[39] -      wordpress/wp-content/themes/notoriousconsultant/404.php[39] - aaLog->logtrace     wordpress/wp-includes/template-loader.php[50] - include     wordpress/wp-blog-header.php[16] - require_once     wordpress/index.php[17] - require   Thanks for your help.


I was going to try to do the line art of one of my drawings on adobe illustrator, but when i open the file the brushes are not there. There's only the basic brush and i can't reduce its size. I've tried to open the image in various formats, but it didn't work. How can i solve this?

I was working on a logo design for a client in Illustrator CS4 when suddenly the default brushes were no longer there. The brush files are still in place but they do not show up in the brushes panel. The options to show the brushes by type are checked but greyed out.   I tried a preference reset, that didn't fix it. I haven't tried any new brushes because the brush I needed was in the stock set. I know its bad form not to try everything but I needed one of the stock brushes to tweak an existing design.


I am working on a customer community using Customer Service (Napili) template. I have a requirement to override the new button of custom object so that some of the details can be auto-populated based on login user. I get to know standard new button cannot be overridden using lightning component the only way i could figure out is to disable the standard button and create a new Lightning component then add it to the custom content layout of record list view. Is there any better workaround to resolve this issue.

I am trying to override a standard "New" button that appears when Case tab is clicked ,so i navigated to new button on the object and i see lightning component bundle is one way to override but when i select the dropdown i dont see my lightning components , is this Beta? or do my lightning component need to implement something ? or below answer in the link is what needs to be implemented for now lightning comp in VF?     standard-buttons-with-a-custom-lightning-page


The following    \usepackage{hyperref}   \newcommand{\mylink}{\href{http://foo.edu/level%20one.html}{Answer}}     gives an error because of the % sign. Is there a work around?

I'm using the url package. Now, I have some some url with a percent sign in it and want to place it in a footnote. When I let the % where it is, I get a comment, and the whole thing fails to compile because of some unmatched brackets. When it's at the end of a line, it doesn't show up at all in the result. When I write \% instead, this gets literally into the output—but I want the url to be displayed correctly.  What could I do?


I'm able to import an object into Blender which was created in MagicaVoxel. The object keeps the desired texture in Blender and looks like this in Edit Mode.  I want to add a "Rounded Edges" or "Rounded Grids" effect onto this object so it looks similar to this: The result should be useable in Unity as well. Other solutions from this site like  sadly don't work. I've tried to work with Normal Maps and UV Mapping but these approaches apparently didn't work due to the shape of the object and due to the fact that it comes with material.

I'm making a scene in Blender with manufactured mechanical and electrical objects - cylinders, metal objects and so forth. I want to make these look real, be fully present with a sense of mass and substance.  3DCG has a tendency to make everything very sharply geometric, often looking mathematical and artificial. In other scenes, some organic curves, normal maps or particle systems would help make object look real. Like for example, making a simple plastic dog model look more believable, one can add more vertices for better definition, add texture layer, add fur etc.  My scene shows clean resistors, wires, metal strips and such, all sharply geometric. It's tricky to find ways to make the result less mathematical and more substantial, realistic and interesting to the eye.  What are some effective ways to add realism to these objects?


Whenever I apply mirror modifier to my mesh the mirrored part becomes deformed and wrinkled as shown in the image. I exported the mesh as obj and opened it in another window and tried to mirror it again but the same thing still happens. How can I fix this? Thanks in advance  .blend file:

The model is vivisected right down the middle along the z axis. The right leg is rendering funny and I assume if I can get that fixed everything else will fall into place. I tried flipping normals, changing shading types - can't think of anything else to do.


I am using kubuntu 14.04 lts running on intel core i3,and has amd 6000m radion gpu  When I am going to install cmake or virtual box using terminal I always get this:error  sudo apt-get install cmake Reading package lists... Done Building dependency tree        Reading state information... Done The following extra packages will be installed:   cmake-data gcc gcc-4.8 libasan0 libatomic1 libc-dev-bin libc6-dev   libgcc-4.8-dev libitm1 libtsan0 linux-libc-dev manpages-dev Suggested packages:   codeblocks eclipse gcc-multilib autoconf automake1.9 libtool flex bison gcc-doc   gcc-4.8-multilib gcc-4.8-doc gcc-4.8-locales libgcc1-dbg libgomp1-dbg   libitm1-dbg libatomic1-dbg libasan0-dbg libtsan0-dbg libbacktrace1-dbg   libquadmath0-dbg glibc-doc The following NEW packages will be installed:   cmake cmake-data gcc gcc-4.8 libasan0 libatomic1 libc-dev-bin libc6-dev   libgcc-4.8-dev libitm1 libtsan0 linux-libc-dev manpages-dev 0 upgraded, 13 newly installed, 0 to remove and 0 not upgraded. Need to get 2,618 kB/14.8 MB of archives. After this operation, 57.5 MB of additional disk space will be used. Do you want to continue? [Y/n] y Media change: please insert the disc labeled  'Kubuntu 14.04 LTS _Trusty Tahr_ - Release amd64 (20140416.1)' in the drive '/media/cdrom/' and press enter   I've searched lot on google but cant get satisfactory answer.  I am expecting answer to solve this problem.

When updating I got this error message:  W:Failed to fetch cdrom://Ubuntu 11.10 _Oneiric Ocelot_ - Release amd64 (20111012)/dists/oneiric/main/binary-i386/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs W:Failed to fetch http://ppa.launchpad.net/synce/ubuntu/dists/your_ubuntu_version/main/source/Sources  404  Not Found   What to do?


I am using springer svjour3. I want the reference numbers to be in square brackets in the reference section.  For example:     [1] Moritz AR, Zamchek N (1946) Sudden and unexpected death of young   soldiers. Arch Pathol 42: 459- 494.      [2] Janssen W, Naeve W (1975) Der plötzliche Tod aus natürlicher   Ursache. In: Müller B (Hrsg) Gerichtliche Medizin. Springer, Berlin   Heidelberg New York, Bd 1, 2. Aufl. S 248-304   What package do I need to include to make reference numbers include in square brackets?  This is my code:  \RequirePackage{fix-cm}   %\documentclass{svjour3}                     % onecolumn (standard format)  %\documentclass[smallcondensed]{svjour3}     % onecolumn (ditto)  \documentclass[smallextended,envcountsame,envcountchap,oribibl]{svjour3}     % onecolumn (second format)  %\documentclass[twocolumn]{svjour3}          % twocolumn  \smartqed  % flush right qed marks, e.g. at end of proof %  \usepackage{graphicx}  \usepackage{multirow}  \usepackage[linesnumbered,ruled,vlined]{algorithm2e}  \usepackage{array}  \usepackage{amsmath}  \usepackage{mathrsfs}   \usepackage{amssymb}   \usepackage{algpseudocode}  \usepackage[section]{placeins}  \usepackage{hyperref}  \bibliographystyle{spbasic}  % % \usepackage{mathptmx}      % use Times fonts if available on your TeX system   \begin{document}   \begin{thebibliography}{}   % and use \bibitem to create references. Consult the Instructions  % for authors for reference list style.   \bibitem{Schouten}   Schouten K, Frasincar F 2016 Survey on aspect-level sentiment analysis, In:IEEE  Transactions on Knowledge and Data Engineering 28(3):813–830.  \bibitem{Pang}  Pang B, Lee L, Vaithyanathan S 2002 Thumbs up?: sentiment classification using  machine learning techniques, In: Proceedings of the ACL-02 conference  on Empirical methods in natural language processing, 10:Association  for Computational Linguistics,79–86.  \end{thebibliography}  \end{document}

The editor asked me to use the following format.      Reference   1. Author, blah blah   Instead of      Reference   [1] Author, blah blah ...   Even though in the main text, [1] style has been used.   For example,        Smith [1] has proposed ...      Reference   1. Smith,      This is what I want.   Could you please advise how I can do the above?  Thanks in advance.


I'm just wondering if if I'm going to have to build a disc or write a disc.   If I need to build a disc in order to make it bootable, can you give me some instructions on how to do so? I'd most likely be using Imgburn, but if you would recommend a different burner, I'll gladly take suggestions.

I have downloaded an ISO file recently.  How do I burn it to a CD or DVD or mount it?


At present if you see a question that may be a duplicate and has an easy answer you can post the answers or post a link to the duplicate question.  (Or the few hi-rep users can vote to close it as duplicate, think of normal users here, not the people that read Meta) It is better for Stack Overflow if a link to the duplicate is posted as a comment, or the user votes to close the question as a duplicate.  However, the user gets more rep if he/she posts the easy answer quickly. I'm thinking of something along the lines of:  First person to post a comment that points to possible duplicate gets some rep if the question is closed as a duplicate and at least 2 of the other closers chose that same dupe question.  Whenever someone votes to close as a duplicate, a “possible duplicate” comment should be posted with a link to the other question, if there is not already a link to it in a comments.  (The system now does this)    As Ether said,  The removal of reputation earned from answering a question that is later closed as a duplicate would at least remove the negative incentive, but is that enough to correct this behaviour? Is a “duplicate finder” badge part of the solution?  A bronze badge for being the first person to vote to close a question as a duplicate with the same “duplicate of” question chosen as most closers choose. A silver badge for doing the same 25 times.  See also  , would also help.  Now that the duplicate can be marked by the OP as helpful, we have another trigger to consider for awarding badges and/or rep.

deals with various ways of rewarding the finding of duplicates, a tough and increasingly necessary janitorial task.  Here's a concrete suggestion:   Reward the finder of a duplicate with +10 points if the question gets closed as a dupe. If multiple duplicates are found, reward all finders whose suggestion was voted for at least once by another user. (The limitation is to avoid gaming by making frivolous suggestions when it's obvious that a question is going to get closed as a duplicate.) Reward each following closevoter who picks one of the previously suggested dupes with +2 points if the question gets closed. Punish everyone involved (dupe-finders and dupe-voters) with -5 points, and revoke all rep gained from the dupe-voting, if a question closed as duplicate gets reopened.   A punishment for mis-voting is going to be controversial but in my eyes, it is absolutely essential. Finding a good dupe is a work of love: You need to make sure you understand the OP's question, and you need to scan every potential duplicate for whether it really contains an answer that will help the OP. Everyone dupe-votes carelessly from time to time, so the threat of punishment needs to be present to keep everyone on their toes, just as the threat of downvoting does when you post an answer.  If you think +10 is too high a reward: Consider that finding a duplicate can often be more work than writing an answer, and a correct answer usually nets you at least 10 points, if not much more.   If you think -5 is too much of a punishment: -2 might work as well, although I really think there should be a harsh punishment on an unfair dupe-closing.


I am trying to run a simple sql query but am getting a Null pointer exception. I tried to change everything possible but could not figure out the reason for this exception.  My part of code :  String sql = "Insert into CG (Date,Day,Pre,Sub) values (?,?,?,?)";         try{         pst = conn.prepareStatement(sql);         pst.setString(1, "date");//4 value taken as input         pst.setString(2, "day");         pst.setString(3, "1");         pst.setString(4, "0");         pst.execute();     }catch (Exception ex) {         JOptionPane.showMessageDialog(null, ex);     }   Edit : I am getting NPE at line pst = conn.prepareStatement(sql)         My connection is : Connection conn = DriverManager.getConnection("jdbc:sqlite:E:\\NetBeansProject\\At\\At.sqlite");

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


i personally have been on and off with ubuntu since... 9.04 i belive.  now i'd like to stay with ubuntu for good. i have settled in with 12.10.  the thing is, im not an expert in this field, i do not have professional knowledge on source coding not to mention programming language (basic c is all i've got, except all the pythons i played with in my calculator when i was in high school...)   ubuntu is always developing and there have always been problems and solvings people worked out. and i am more than greatful for this huge community.  now i want to contribute. not in a sence that i would donate money, but actually problem solving. I have been having so many stability issues with ubuntu which is why i have been on and off with it.  i am wondering how and where i should start with tackling problems if i encounter one.  any advice please, would be much appreciated, thanks!

I would like to know what kinds of contributions someone can make to Ubuntu. Such as Programmer, User, Proofreader, etc.


For example all files matching ".doc" and ".txt". I know how to find one extension type, but I need multiple without running multiple commands.

I am trying to find two extensions in command line but when i do it will only return one of the extensions. can you tell me what I am missing?   Here is my command;  [root]# find /etc -name "*.txt" -o -name "*.log" -type f -mtime +7 -exec echo {} \;


I teach children aged 10 to 14. I teach children ages 10 to 14.

Here is a sentence excerpted from ,     Teen suicide is a growing health concern. It is the third-leading cause of death for young people ages 15 to 24, surpassed only by homicide and accidents, according to the U.S. Center for Disease Control and Prevention.   I've heard people use both "people aged from X to Y" and "people ages from X to Y" quite often, but I've always been believing that only the former is grammatically correct, whereas in the latter the "ages" doesn't seem to serve as any grammatical component of this sentence. So when I see an APA paper use "ages" in that way, I am just quite surprised: I just can't believe such an authoritative and rigourous academic institution will let such an explicit (and indeed naive, even to a non-native speaker's eyes) grammatical mistake survive in their publications. I'm aware that in daily language usage one ought not to become so fussy over insignificant matters like this, but I do wonder whether it should be paid attention to in academic writings.  OR, using "ages" in that way is no longer considered a grammatical mistake? Honestly I don't think this'd be true, but if it really is, I'd be grateful to be informed. Thanks!


I'd like to show that $${n \choose k} \ge \left( \frac{n}{k} \right) ^ k$$  I understand that $\forall \delta \ge 0$, $$\frac{n}{k} \le \frac{n-\delta}{k-\delta}$$ since as $k \le n$, then $k - \delta \le n - \delta$, thus as $\delta$ grows, the fraction grows too. But I can't show it formally.

The simple inequality that $\left(\frac{n}{k}\right)^k \leq \binom{n}{k}$ has a number of different proofs. But is there a particularly intuitive, short and elegant proof that uses the natural interpretation of binomial coefficients, for example. I would ideally like a proof which is also accessible to students with very limited prerequisite knowledge.  Here is the best proof that I have seen which is less intuitive than I was hoping for.  First we first prove that $$\frac{n-i}{k-i} \geq \frac{n}{k}$$  for $i<k\leq n$.  This follows from  $$0\leq (n-k)i = k(n-i) - n(k-i) =  k(k-i)\left(\frac{n-i}{k-i}-\frac{n}{k}\right),$$ and $k(k-i)> 0$, so $(n-i)/(k-i) \geq n/k.$  Now we multiply the over $i\in\{1,\ldots,k-1\}$ to obtain  $$\frac{n(n-1)\cdots(n-k+1)}{k(k-1)\cdots 1} \geq \frac{n^k}{k^k},$$ or equivalently $\binom{n}{k}\geq (n/k)^k$.


I noticed the following: $$2 \times 3 = 5+1$$ If you switch the operators, it is still true: $$2+3 = 5 \times 1$$ There is another obvious/trivial example where you can swap the operators: $$2\times 2 = 2+2$$ I think these are the only solutions (for positive integers). Can anyone give an elegant proof?

There is a 'nice' relationship between the integers (1,5) and (2,3) as  $$1+5=2 \times 3;$$ $$1\times 5 = 2 + 3.$$  So I tried to find all positive integers pairs $(a, b)$ and $(c, d)$ such that $$a+b=c \times d;$$  $$a\times b = c + d.$$  To find this, $a, b, c, d$ must satisfy $$(a+1)(b+1)=(c+1)(d+1).$$ However, this condition is only necessary but not sufficient. Any idea?


Prove that if $f$ is integrable on $[a ,b]$ then $|f(x)|$ is also integrable on $[a ,b]$ and $|∫_a^b f(x)\,\mathrm dx|$ ≤ $∫_a^b |f(x)|\,\mathrm dx$

Show that if $f$ is integrable on $[a, b]$ then $\lvert f \rvert$ is also integrable. Hint: Show that $$U (P , \lvert f \rvert) − L(P , \lvert f \rvert) ≤ U (P , f ) − L(P , f ).$$ I have: $$U (P , \lvert f \rvert) \ge U (P , f )$$ and $$ L(P , \lvert f \rvert) \ge L(P,f)$$ Thus, $$U (P , \lvert f \rvert) − L(P , \lvert f \rvert) ≤ U (P , f ) − L(P , f ).$$


I installed A app called Tuxpaint But when I looked for it I could not find it. I know it installed because on the Lubuntu Software Center It showed up on installed Packages. Because I can't find the location I can not use the app.

I'm new to Ubuntu and would like to know where I can find the location of program files for programs installed from the Ubuntu Software Center or the Terminal.


I have a regression with a linear and quadratic term.  The linear coefficient is not significant but the quadratic is significant.  Does it make sense to have no linear effect but a quadratic effect in a regression model?

I have a (mixed) model in which one of my predictors should a priori only be quadratically related to the predictor (due to the experimental manipulation). Hence, I would like to add only the quadratic term to the model. Two things keep me from doing so:   I think I read somehwere that you should always include the lower order polynomial when fitting higher order polynomials. I forgot where I found it and in the literature I looked at (e.g., Faraway, 2002; Fox, 2002) I cannot find a good explanation. When I add both, the linear and quadratic term, both are significant. When I add only one of them, they are not significant. However, a linear relation of predictor and data is not interpretable.   The context of my question is specifically a mixed-model using lme4, but I would like to get answers that could explain why it is or why it is not okay to inlcude a higher order polynomial and not the lower order polynomial.  If necessary I can provide the data.


I am looking at a problem that roughly says  If $a,b \in [0,1)$, and $\lfloor na\rfloor+\lfloor nb\rfloor=\lfloor n(a+b)\rfloor$ for every $n\in\mathbb{N}$, then $a=0$ or $b=0$.  The proof that was supplied was the following:  Assume $ab\neq 0$ and write $a=2^{-a_1}+2^{-a_2}+\ldots+2^{-a_s}$, and $b=2^{-b_1}+2^{-b_2}+\ldots+2^{-b_t}$, and wlog let $b_t\geq a_s$. Then taking $n=2^{b_t}-1$ gives $$\lfloor na\rfloor+\lfloor nb\rfloor=\Big\lfloor \sum_i 2^{b_t-a_i}-a\Big\rfloor+\Big\lfloor \sum_i 2^{b_t-b_i}-b\Big\rfloor=\sum_i 2^{b_t-a_i}-1+\sum_i 2^{b_t-b_i}-1,$$ whereas the RHS becomes $$\lfloor n(a+b)\rfloor=\Big\lfloor\sum_i 2^{b_t-a_i}+\sum_i 2^{b_t-b_i}-a-b\Big\rfloor=\sum_i 2^{b_t-a_i}+\sum_i 2^{b_t-b_i}-1,$$ a contradiction.  However as far as I can see this only applies if $a,b$ have finite decimal representations in base 2. Once one generalises to arbitrary $a,b\in[0,1)$ I think this proof becomes insufficient. So I was wondering if there is a proof that can show this result for all such $a,b$, or if this result actually fails without the assumption that $a,b$ have finite base 2 decimal representations.

Interesting problem     Let $a,b,c$ be real numbers such that   $$\lfloor na\rfloor+\lfloor nb\rfloor=\lfloor nc\rfloor$$   for all postive integers $n$.   Show that:   $$\{a\}\cdot\{b\}\cdot\{c\}=0$$   where $\{x\}=x-\lfloor x\rfloor$   My partial work: since for any postive intger $n$,have $$\lfloor na\rfloor+\lfloor nb\rfloor=\lfloor nc\rfloor$$ then we have $$a+b=c$$ because consider $$\Longrightarrow \lim_{n\to\infty}\dfrac{\lfloor na\rfloor+\lfloor nb\rfloor}{\lfloor nc\rfloor}=1$$ since $x-1<\lfloor x\rfloor \le x$,so we have $$na+nb-2<\lfloor na\rfloor+\lfloor nb\rfloor\le na+nb$$ so $$1=\lim_{n\to\infty}\dfrac{\lfloor na\rfloor+\lfloor nb\rfloor}{\lfloor nc\rfloor}=\dfrac{a+b}{c}$$ I guess we can use by contradiction prove this. Assume that $\{a\}\cdot\{b\}\cdot\{c\}\neq0$, then $a,b,c$ all not integer.


I'm trying to understand how many licenses I'm supposed to purchase and check if I have the correct amount of purchased licenses. I have Windows Servers & SQL Servers in virtual environment.  From my understanding:    Windows Server only:  Server with Windows Server – the license is 'Per CPU'.   A Server with 1 CPU & 2 Cores total - need 1 windows license.  A Server with 2 CPU & 4 Cores total - need 2 windows license.  A Server with 2 CPU & 8 Cores total  - need 2 windows license.    SQL Server:  A server with SQL server – The license is 'Per CORE'.  Also needed Windows Server license, amount depends on the number of CPU.  A Server with 1 CPU & 2 Core total – need 2 SQL licenses.  A Server with 1 CPU & 4 Core total – need 2 SQL licenses.  A Server with 2 CPU & 8 Core total – need 4 SQL licenses.  A Server with 2 CPU & 12 Core total – need 6 SQL licenses.    Please let me know if my example is correct, So I can be sure I understand the licensing as needed.  Thank you!

This is a  about Licensing.    Questions on licensing are off-topic on Server Fault.  If your question has been closed as a duplicate of this question, then this is because we want to help you understand why licence questions are off topic rather than just telling you "it just is". In all likelihood, this question will not address your question directly, it was not meant to.    I have a question regarding software licensing. Can the Server Fault community please help with the following:   How many licenses do I need? Is this licensing configuration valid? What CALs do I need to be properly licensed? Can I run this product in a virtual environment? Can I downgrade this product to an earlier version? Am I entitled to feature X with license Y?


I would like to write a shell script in order to write all files ending with .tif in  a given directory and all its subdirectories to a csv file.  The directory contains various sub-directories and those can also contain .zip folders so the script should be able to extract the names from zip folders too.  I first thought about separating these steps though (unzipping and getting the filenames) but I'm not sure if this is really necessary.   Since I'm really new to working with the Shell, any help would be appreciated.

I've looked at , and while it works there a few issues:   All converted images are placed in the directory from which the command is called. The original images are kept.   I need to convert around 70,000 .tif and .jpgs to .pngs.  It's really important the the files when converted are placed in their normal directories.    I can do a batch rm of .tff/.jpg's at the end if that's the best way to handle removing the old files.


Many years back (more than 10) I came across a PDF for Harry Potter and The Order Of Phoenix. It had a completely different story line. If I remember correctly, in the first chapter Harry was meddling around in the garden thinking about his own physical growth and over the course of the book there was a love angle between him and Hermione. Some portion that I can recollect from the first chapter is about a snake Harry encounters in the garden and the snake is not in a really good shape and Harry takes care of it. Rest of the year in the school was completely different too, Sirius doesn't die as per the story and it's a gradual build up to his and Hermione's relationship. I have never been able to find that PDF again.

I was reading  where someone finds out that they've actually read a fan-fiction version of Harry Potter and the Order of the Phoenix. It's bloody hilarious, I'm crying from laughing so much!              First part:   A: So Dudley dies in Harry Potter right?   B: Do you want him to?   A: No I just got to the part where he was killed but Julia didn't remember that so I just want to make sure I'm not reading some weird fan fiction   B: Uhhhh   B: What book are you on?   A: Finishing up order of the Phoenix   B: He doesn't di in order of the Phoenix   B: Are you serious?   A: He doesn't jump off a building?   B: What the heck, no.   B: I guess it's not a huge spoiler, but he doesn't die at all.   A: What the what?! You're trolling me   B: No, I'm not. Dudley doesn't die. In fact as the books go on, he gets almost no screen time. Why is he jumping off a building?   A: He was placed under the imperious curse and made to jump off his school   A: By the rat guy   B: Uh, I don't know what you're reading but it's not the order of the phoenix.        Second part:   B: Did you get all your books from the same place?   A: It was all of them in one collection. Maybe it segued into the sixth?   B: No, that never happened in the books   A: Dudley is never forced to commit suicide   B: Nope   A: And I assume the scenes where Harry and hermione get intimate?   B: Ok, now you're trolling me   A: Nope   B: There's no sex in Harry Potter   A: Wizarding age of consent is 15   A: What?! The order of the Phoenix was full of it!   B: In the real order of the phoenix Harry is barely able to kiss a girl for the first time, and it's not Hermione   B: At no point did you think, wait this seems kind of weird for a kid's book?   A: ARE YOU SERIOUS?   A: I mean I'd heard they got more mature and dark as it went on   A: Okay, so I think I know what the answer is going to be, but did Draco and Ginny fake a rape scene?   B: No   B: I can't even...   B: I'm laughing so hard I'm crying   B: Ok, I'm going to need you to give me a rundown of everything that's happened so far in these books.   A: What sick freak wrote this?!?!   A: OMG   Fan-fic details:   Dudley gets placed under the Imperius Curse by Wormtail   Caused to commit suicide by jumping off a tall building*  Harry and Hermione get intimate* Draco and Ginny fake a rape scene* Harry does a lot of running and becomes muscly A professor (perhaps Snape) gives out morning after potions Harry has a pet snake called 'Cassandra' or 'Cassie' for short   Snakes have "the Sight" and can see into the future The bigger the snake, the further into the future* [they can see]    More details can be found in the Twitter convo mentioned above if needed. Asterisks mark the points taken verbatim from the Twitter conversation.   What Harry Potter Fan-fic is that?


I have a performance problem with searching in varchar columns in SQL Server 2016. Considering these tables have plenty of rows, for example 60000 rows each one.   Tables  CREATE TABLE Persons ( PersonID int, LastName varchar(255), FirstName varchar(255), CityID int)  CREATE TABLE Cities( CityID int, CityName varchar(255))   Code  I have a problem like this:  SELECT p.PersonID, p.FirstName , c.CityID,c.CityName  FROM PERSONS p JOIN CITIES c ON c.CityID = p.CityID  WHERE       p.FirstName like '%'+@search+'%'    OR p.LastName  like '%'+@search+'%'    OR c.CityName  like '%'+@search+'%'   Possible Solutions in my mind:   Creating a full text index for each table. Creating Columnstore indexes. Replicating the columns to another table and searching there.   I've searched in books like: "SQL Server 2012 Query Peformance Tunning" and "Expert Peformance Indexing for SQL Server 2012". And of course, a lot of sites and blogs on the internet.I would appreciate another suggestions to solve this issue.

maybe there is a simple answer to my problem:  I have a mssql table ('Person') with a field for first and one for last name. I am coding a Program, where the User should be able to search for persons.     SELECT id, firstname, lastname FROM Person WHERE firstname LIKE   @searchstring + '%' OR lastname LIKE @searchstring + '%'   doesn't work very well, because if the user types 'John W' nothing is found.  For example the person I search for is called John Williams: It should work with searchstrings like 'John W', 'Williams Jo', 'Will' or 'Joh'  Concatenating first and lastname and use %Searchstring% also doesn't work well, because if the searchstring is e.g. 'Will' it should find people who are called Will, Willibald, Williams or Willson or something like that, but not a Person called Goodwill e.g.  And the query should be as fast as possible, because it is executed at every keydown...  edit: forgot to mention that the database must not be changed, because it is from another company.  Thank you for your help.


I'm currently doing a master's in statistics, and I'd like to do a PhD in statistics and focus on machine learning.  However, I am almost certain that I will receive a C+ in my (calculus-based) probability theory class. A C+ would be an outlier for me; I never got lower than an A- in undergrad and an A in grad school (this includes real analysis classes). If it makes any difference, I will have a published article in machine learning by the time I apply to statistics PhD programs.  Also, I don't think this is a duplicate question. I didn't have a serious medical emergency this semester, but I felt ill during the final and a poor grade there would sink my grade. Also, other questions ask about non-relevant classes, but I think that this grade is relevant.  Is there any way to make up for this? For example, if I did well in a class that depended on the probability class, would admissions officers be willing to look past this blunder?

I'm currently an M. Phil student in Math and I failed a course last semester because I was not able to hand in a home work assignment (which was worth 40% of my grade) on time (I was 30 minutes late).   Apart from that I'd say I'm a fairly decent student, I got an upper second class honours bachelors degree, I have a B+ and A's for all my other courses in my current programme and I'm almost finished with my first paper to be published.   I've however been deeply worried about this failure as it would reflect poorly on my transcript if I were to apply to a Ph.D or another Master's programme.   Will my failing grade affect my chances of getting into a competitive programme or greatly lower my chances of getting a scholarship?


The edge loops do not go on the inside of the cube wall. I made the wall from a cube following a floor plan. I tried using the knife tool but the edges it generated were not able to be selected. What is a solution to this. The walls all have 4 vertices and are not n-gons. Thanks Blend File:

Alright so I've seen some postings about loop cuts and done some research. I am very new to blender and modeling overall. I am trying to loop cut this concrete barrier. Now I'm following a tutorial and kind of did my own thing in some areas. I cleaned it up following some instructions in another answer here on stack exchange.  I can't for the life of me figure out why I can loop cut around the whole bottom:   ...but not the whole middle:   I see this marked as answered by another question. That question refers to ngons and inside faces. Now once again I'm totally new to this. I looked on the inside. I don't believe I have inside faces or any ngons by the terms I've read online in my research.  Here is a wireframe picture and the inside view:     Maybe I'm missing something the answers on other posts are saying. If so and you know what it is I'd be very appreciative of what it is.


On the question  I learned I need to add {} (may be also \relax) every time I use a text command like \latex to print the the word LaTeX nicely and keep the correct text hyphenation.   But while fixing my document template accordingly to the hyphenation rules, I found several commands appended with a single backslash as in:  criadas sequencialmente, o \abnTeX\ instrui o \LaTeX\ para que uma vírgula seja   Why they were appending a backslash on it? Can I still fix the hyphenation with \latex{}\ or I should use only \latex{} or perhaps \latex\relax

I have a definition:  \newcommand{\arnold}{Arnold Schwarzenegger}   When I refer to it by:  \arnold is a   it is rendered as:   Arnold Schwarzeneggeris a    In order to have a space in front of "is" I would need to write  \arnold\ is a   Is there some other shorter way?


$S=1+x+x^2+x^3+...x^{n-1}=\dfrac{x^n-1}{x-1}$  Now I wanted to prove it using induction. Using induction for $n=1$, gives us $S=1$ which is prime. OK!  Now assume for $n=m$, it is true.  Then $\dfrac{x^n-1}{x-1}$ is prime $\implies m=prime$  Now if $m\ne2$ or $m\ne1$, then $\notin m+1$ such that $m+1$ is $ \space prime$   Thus w/o loss of generality, let $m+k$ where $k\in \mathbb{N}$ and $k<m$ such that $m+k$ is prime and also assume $m+k$ is the next prime after $m$  Now required to prove $\dfrac{x^{m+k}-1}{x-1}$  is prime  We see here that  $\dfrac{x^{m+k}-1}{x-1}=1+x+x^2+.....x^{m+k-1}=1+x+x^2+...x^m+x^{m+1}+...x^{m+k-1}$   Now we know that $\underbrace{1+x+x^2+...x^{m-1}}_{\text{is prime by hypothesis}}+x^{m}+...x^{m+k-1}=\mathbb{P}+x^m(1+x+x^2+...x^{k-1})$  Now as $k<m$, we can say that $(1+x+x^2+...x^{k-1})$ is also prime if we use strong induction.  So now we get $\mathbb{P}+\underbrace{x^m\underbrace{(1+x+x^2+...x^{k-1})}_{\text{is prime by using strong induction}}}_{\text{is composite}}\implies \mathbb{P}+\text{a composite number}$ which is a possible candidate for prime.  But how can I say that if I add it, I must get a prime again?  Or Is the approach entirely wrong?Please suggest with reasoning.  Ok so by popular demand let us use contradiction here   Assume $n$ is not prime.  Then what to do next?

Will be glad for a little hint: let x and n be positive integer such that $1+x+x^2+\dots+x^{n-1}$ is a prime number then show that n is prime


I am trying to create the following program in which I need to turn the input String's characters into lowercase to ease my work.  I tried using toLowerCase(); first but it didn't work. Then I tried using toLowerCase(locale); and yet I have not succeeded.  public static void  Mensuration() {     Locale locale = Locale.ENGLISH;     Scanner inputz = new Scanner(System.in);     System.out.println("Which kind of shape's formula would you like to find out.2D or 3D?");     char dimension = inputz.nextLine().charAt(0);     if(dimension == '2') {System.out.println("Okay so which shape?");     String dimensiond = inputz.nextLine().toLowerCase(locale);     if(dimensiond == "rectangle") {System.out.println("Area = length x breadth\nPerimeter = 2(length + breadth)");}         }         }   I expected the program to give the accurate output but the thing that happens is that there is no output actually!!

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


My data sets are a combination of numerical and categorical data. The categorical data are inputted in a one-hot encoding manner. I would like to ask if it is necessary to standardise the data sets first here before performing PCA? If so, what would be a good way to standardise the data set?

I have multiple datasets that I am attempting to use principal component analysis (PCA) on in order to infer the underlying structure of the data.  I'm attempting to predict growth increment of conifers (the response which apparently needed to be cube root transformed for my original linear models).  My predictor variables include: continuous (some log-transformed like size-related variables, some compositional, and some traditionally scaled); binary; ordinal; and nominal (of which I'm pretty sure I can order with respect to site productivity).  I'm mostly attempting to make inferences because some of my previous models from linear regression have not produced significant terms corresponding to categories like health or climate and I feel that they should have.  I've read in Joliffe (2002) that I might want to leave my compositional data uncentered.  Forgive my naiveté, but I'm wondering if I should also do this for my binary data.  It also seems that I might not want to scale these since they're already on a 0 - 1 scale but I'm not sure.  After only using my continuous predictors (including compositional variables), it appears that a size principal component makes up the largest portion of the variability and Joliffe also mentions that one might want to attempt a "double-centering" of the log-transformed data if this is the case.  I don't know if this is even possible since the log-transformed data only makes up a small portion of my datasets.  Finally, I should ask if having such a combination of data types will complicate analysis so much that it will make inferences unreliable.  I am currently using R for this analysis.  Thank you.


This is a nice limit $$\lim_{n\rightarrow \infty}\underbrace{\sqrt{2+\sqrt{2+\sqrt{...+\sqrt{2}}}}}_{n\text{ times}}$$ and it is solved with well-known trigonometry formulas. The result is 2. The question is: can be, this limit, solved in other ways?  Thanks.

(Fitzpatrick Advanced Calculus 2e, Sec. 2.4 #12)  For $c \gt 0$, consider the quadratic equation $x^2 - x - c = 0, x > 0$.  Define the sequence $\{x_n\}$ recursively by fixing $|x_1| \lt c$ and then, if $n$ is an index for which $x_n$ has been defined, defining  $$x_{n+1} = \sqrt{c+x_n}$$  Prove that the sequence $\{x_n\}$ converges monotonically to the solution of the above equation.  Note: The answers below might assume $x_1 \gt 0$, but they still work, as we have $x_3 \gt 0$.    This is being repurposed in an effort to cut down on duplicates, see here: .  and here: .


I'll start by saying I tried everything I found. And still nothing worked.  Preface  I've converted my old MBR to GPT partition table. I actually thought I'll just have to reinstall GRUB2 and eventually Windows and it'll be fine. It wasn't. I used gdisk(GPT fdisk) to do the conversion without data loss.  Problem  At first, my Windows wouldn't load. Then, I'd do repair of BCD, where the problem was, and ended up not being able to boot to HDD at all and stuck at grub rescue screen. Tried full repair, and every other repair I run into, same thing. When I reinstall/repair GRUB, I get BCD error at windows boot.  Solutions and further problems  The most obvious one - reinstall Windows. Well, not gonna happen. It won't install on GPT without UEFI hardware. Protecting me from myself, so Microsoft-style. I made a terrible mistake and didn't realize the problem was at the partition TABLE, and not the partition itself, and formatted Windows partition. I didn't lose anything important - well, except Windows.  Next thing I tried was hybrid-MBR. I guess no one told Windows installer that, since it gives the same error(tried windows 7 and 8 both 64-bit). I used gdisk recovery menu for that, and went through all the inputs, and finished working properly.  Next was the attempt of DUET installation. Where I expected it to fail boot, due to my AMD CPU, it didn't even manage to install. I used duet-install script which I downloaded together with the files . The script stops always at the same spot:  Partition starts at sector 2048. And I've looked at the script's source, it should soon print out next line(it printed 13 lines in a moment), but nothing happens, for hours. Tried re-running, re-downloading, running from live CD, and nothing. Here's the whole output:     Will install SYSLINUX to the MBR Path to SYSLINUX is   /usr/share/syslinux       Path to bootduet is   /home/ubuntu/Downloads/tianocore_uefi_duet_builds-tianocore_uefi_duet_installer/BootSector      Path to UEFI DUET is   /home/ubuntu/Downloads/tianocore_uefi_duet_builds-tianocore_uefi_duet_installer      Will install UEFI version UDK Target partition is /dev/sda1       Will   create a FAT filesystem called 'ESP' on the target partition      Target disk (for storing MBR boot code) is /dev/sda Partition number   is 1       Partition starts at sector 2048   [edit] Tried installing XP, but it can't format the unformatted space. I tried formatting it with GParted to ntfs, but installation still registers it as unformatted space(and nothing else except it). But to be completely honest - that cd was shelved for a long time, I barely found it, and I have no idea is it x64(probably isn't so not gonna work).  So, I'm stuck now. Help please?  Also, reformatting whole HDD isn't an option. Windows isn't worth it, I'd rather stay with Linux. Also, conversion back to MBR neither, since as far as I read, it includes formatting. Also, I got 7(or 8?) partitions(5 on old MBR, but I used extended partitions... was messy).  Specs  MoBo: ASUS M5A78l-M LX CPU: AMD Athlon II x3 450  Current Workaround (well, except the obious(linux))  I got windows 8 installation to start in VirtualBox. It's some progress, but I don't want to be stuck with VM every time I  want to launch Windows.  Edits  I've played around with a duet-install script. If I type some letter and hit enter, it prints parted: invalid token: [letter]. If that letter is 'c', it prints Unknown partition table type ! Aborting!, which is obviously not the case. I guess I'll have to analyze the source deeper to get to the root of problem, because that script is the best solution to me now.  Got to the point where script stops executing: ptLine=parted "${targetDisk}" print | grep "Partition Table"`. Will try to find a solution by skiping checks and set values to match my system.  I have edited the script, and removed the part that didn't work, and finally manage to install DUET. Or at least it said so... I notice no changes to BIOS, it's all like on beginning. Still won't work.

My PC does not support UEFI BIOS, but it has Legacy BIOS. The motherboard is "P5LD2-X1333".  I need to install Windows 8 on the 3TB hard drive with GPT scheme, since as we know, the MBR scheme does not support more than 2TB space. Also, you can not boot OS from a GPT hard drive without UEFI BIOS.  So how can I use the hard drive with 3TB space with OS and without UEFI BIOS?


- the Gelt hat can be awarded when it's December 16th somewhere. However, Chanukah (my preferred transliteration), being a Jewish holiday, starts at night. That's 25 Kislev on the Hebrew calendar.  If the hat is for Chanukah, it shouldn't be awarded based on the Gregorian calendar. It should be awarded based on the Jewish calendar.

During Winter Bash, users can earn hats. But sometimes it seems that a hat was awarded even though its requirements weren't (yet) met, or vice versa.  What could be the reason for this?


In a book of Alexander McCall Smith I found this phrase:     No historical novelists need apply.   Why isn't it this with a  to for the infinitive?     No historical novelist need to apply?

The header of  states:     High-level languages need not be slower than low-level ones.     Why use need not instead of do not need? What does it mean? Also, why no to before be?