Updated from Ubuntu 12.04 LTS Wubi to 13.10, won't boot now

Yesterday night, I have installed Ubuntu 12.04 LTS through Wubi, since I don't want it to be on a CD or a USB. Later that night, I have updated the version from 12.04 LTS to 13.10. It asked me to reboot to complete the installation of the update, so I did that.   Afterwards, like normal booting, it asked me which OS do I want to open. Windows 7 or Ubuntu, so I chose Ubuntu, of course, but, after I clicked on the Ubuntu button, the Ubuntu start up screen shows (the Ubuntu logo which has five grey loading dots under it) and then it disappears and turns into a black screen with a white line. The white line isn't even moving. What's going on? Please help.


Connecting two points on the boundary of an open, connected and bounded set $Q\subset \mathbb{R}^2$ with a path $\gamma\subset \overline{Q}$

Let $Q$ be an open connected and bounded subset of $\mathbb{R}^2$. Is it true that for any two points $x,y\in \partial Q$, there is a path $\gamma \subset \overline{Q}$ which connects $x$ and $y$? I know that $\overline{Q}$ is connected and $Q$ is path-connected, but I still wasn't able to answer my question.


Somehow my Ubuntu wakes up from suspend on its own with lid closed

I got Ubuntu 14.04 installed on Dell Inspiron 5521. When I close the lid it falls asleep. Often when later I pass by it I notice that its LEDs indicate it's awake. Indeed it is awaken when I check.  I double checked that mouse movements and clicks cannot wake the beast up. What else awakes it? Is enslaved by FBI or NSA?  I don't have wired LAN, and only my notebook and my smartphone in WiFi LAN.  $ sudo journalctl | grep systemd  нояб. 05 13:55:03 anima systemd-journal[25572]: Allowing runtime journal files to grow to 78.5M. нояб. 05 13:55:03 anima systemd-udevd[127]: starting version 204 нояб. 05 13:55:03 anima systemd-udevd[494]: starting version 204 нояб. 05 13:55:03 anima systemd-hostnamed[4590]: Warning: nss-myhostname is not installed. Changing the local hostname might make it unresolveable. Please install nss-myhostname! нояб. 05 13:55:03 anima systemd-hostnamed[26523]: Warning: nss-myhostname is not installed. Changing the local hostname might make it unresolveable. Please install nss-myhostname! нояб. 05 13:55:03 anima systemd-hostnamed[1537]: Warning: nss-myhostname is not installed. Changing the local hostname might make it unresolveable. Please install nss-myhostname! нояб. 05 13:55:03 anima systemd-hostnamed[10422]: Warning: nss-myhostname is not installed. Changing the local hostname might make it unresolveable. Please install nss-myhostname! нояб. 05 13:55:03 anima systemd-journal[25572]: Journal started


I am trying to add map of map values, I have to intialize the map key first and then try to add value later. Below is the exact logic i am trying to achieve.  Map<string,Map<string,List<string>>> finalMap = new Map<string,Map<string,List<string>>>();  Map<string,List<string>> subMap = new Map<string,List<string>>(); submap.put('One',new list<string>{'One','TWO'});  finalMap.put('SUB1',new Map<string,List<string>>());  //Do some logics and finally try to add the values with the key  finalmap.get('SUB1').put(subMap); //Error as stated below  System.debug(finalmap);      ERROR :Method does not exist or incorrect signature:   [Map<String,List<String>>].put(Map<String,List<String>>)


How to find transformation matrix, specifically a rotation, between two given 3d vectors?   I've found something about it but with quaternions. I don't know anything about quaternions. So it would be great to find solutions in terms of vectors.  I mean rotation matrix.


Does a standalone neutron have temperature?

Most objects exhibit a property called temperature which measures how much thermal energy is radiated off, and I think the electron(s) inside the atom or molecule is responsible for creating that light. So what happens if that object is an isolated neutron does it have temperature if it doesn't radiate energy? I can't speak calculus and it been quite a while so my algebra is a bit rusty I think you get the drift...


Add trailing slash in bash completion of directory symbolic links

I have a symbolic link for a directory,  e.g ln -s /tmp /xxx  Now when I type /xx and press tab key, bash would complete the line to /xxx   If I press it again it become /xxx/  Now, how can I ask bash to complete /xx to /xxx/ automatically (provided that there's only one match)


The feeling of inferiority entering a PhD program due to one's undergraduate school rank

According to Stanford's Computer Science graduate admissions department this year:     110 students were accepted. Nearly all accepted applicants were from Stanford (BS/MS), MIT, Berkeley, Princeton, Michigan, Texas, Washington, Tsinghua, and the other ivy leagues. About 10-20 were from non-top schools.   I am one of these 10-20. I go to a state college and our curriculum is imaginably not up to par with the elite schools.  I'm scared.  Did anyone experience the similar situation?  How would I prepare myself to hang with the smartest people in this Ph.D. process?  If you're a professor, how much does this affect you in choosing a Ph.D. student?


Extension fields isomorphic to fields of matrices

Suppose $K \subset L$ is a finite field extension of degree $m$. Is it true that there exists some natural $n$ such that $L$ is isomorphic to a subfield of $M^{n\times n}(K)$, the ring of $n\times n$ matrices with entries in $K$? What is the smallest dimension (as a function of $m$) for which an isomorphism exists?  The example I had in mind was the 2-dimensional extension $\mathbb{R} \subset \mathbb{C}$ with $\mathbb{C}$ being isomorphic to $\{ \begin{pmatrix}a&-b\\b&a\end{pmatrix} : a, b \in \mathbb{R}\}$.


What is the solution to the random version of the "Farmers and Pesky Birds" problem from "Math Fun Facts"?

Here's the text of the problem:  Alice and Bob are two farmers each wanting to plant a (countably infinite) row of seeds, side by side in a field. Both of them have pesky birds that hinder their efforts in funny ways. As Alice walks along the row, sequentially dropping her seeds, her bird picks up every fifth seed that she drops. So after Alice "finishes" planting her row of seeds, are there any seeds left? Sure... infinitely many of them. But Bob's bird behaves differently. Bob walks side by side with Alice, planting seeds in his row. After every fifth seed that Bob drops, his bird picks up the first seed that remains in his row. After Bob has "finished" planting his row of seeds, are there any seeds left? No! Each of Bob's seeds gets picked up by Bob's bird, eventually! But that is strange: Alice and Bob are working simultaneously and their birds pick up seeds at the same rate... but Alice's row still has seeds left! How can this be? Presentation Suggestions: Draw a picture of what's happening, as in Figure 1. Be prepared for a discussion about infinity. Students will object that since Alice and Bob can never actually "finish" that there is no paradox. But this is not the real issue, because we can just have Alice and Bob plant the first seed in 1 sec, the second in 1/2 sec, the third in a 1/4 sec, etc. After 2 seconds they will be done planting. The Math Behind the Fact: The nature of this paradox lies in the counter-intuitive nature of infinite sets. An infinite set can be (and is in fact characterized by the fact that it can be) put into one-to-one correspondence with a subset of itself. So, both pesky birds have picked up sets of the same cardinality; one is just a subset of the other.  (Here's the question I would like answered...) OK, if you liked that one, here's a question to ponder: Suppose Charlie is a third farmer, planting seeds at the same rate as Alice and Bob, with a pesky bird that after each fifth seed that Charlie drops, picks up a random seed of those that remain? How many seeds will Charlie have left? An answer is in the reference. [Hint: what is the probability that Charlie's first seed will be picked up?]


how to build simple program run from terminal in ubuntu

I'm writing simple program in c++ using netbeans. I want it should be executable thru ubuntu terminal as other do   like "php samel.php" it works I want something like this   please guide me how to do this


Galois group of $x^6 + 3$ isomorphic to a copy of $S_3$ inside $S_6$

I have seen the the thread   related to the computation of the Galois group of the same polynomial. However, my question is not about the computation itself but about the group presentation of the Galois group. I will explain.  I have determined that the polynomial $x^6 +3 \in \Bbb{Q}[x]$ has Galois group of order 6. The splitting field is $\Bbb{Q}(a)$, where $a$ is a root of $x^6 + 3$. One can take  $a = \sqrt[6]{3}\zeta$ where $\zeta = e^{2\pi i/6} = e^{\pi i/6}$.  Now I have determined the rest of the roots to be:  $$\begin{array}{ccccc} \alpha_1 &=&  a &&& \alpha_4 = -\alpha_1  \\ \alpha_2 &=& \frac{a^4 + a}{2}= \zeta a &&&  \alpha_5 = -\alpha_2 \\ \alpha_3 &=& \frac{a^4 - a}{2} = \zeta^2 a &&& \alpha_6 = - \alpha_3 \end{array}. $$  I have also computed some automorphisms of the Galois group, for example the automorphism $\tau : \alpha_1 \mapsto \alpha_4$ that has order 2, $\sigma : \alpha_1 \mapsto \alpha_2$ that has order 2 and  $\rho : \alpha_1 \mapsto \alpha_3$ that has order 3. The presence of two automorphisms of order 2 tells me that the Galois group is isomorphic to $S_3$  However the problem now is if I want to identify my $\tau,\sigma$ and $\rho$ as cycles in $S_6$, I get the cycles $(14)$, $(12)$ and $(132)$. I don't think these cycles lie in the copy of $S_3$ inside of $S_6$; what am I misunderstanding here?  Thanks.     Edit: I made a mistake in the calculations. We actually need $\alpha_1 = a = \sqrt[3]{3}\zeta$ where $\zeta = e^{\pi i/6}$. I did not take a primitive 6-th root of unity earlier. Now if I write $a = \sqrt[6]{3}e^{\pi i/6}$, then $a^3 = \sqrt{3}i$ and so $\frac{1 + a^3}{2} = \frac{1 + \sqrt{3}i}{2} = \zeta^2$. So indeed with the redefined $\zeta$ and $a$, the equations now are   $$\begin{array}{ccccc} \alpha_1 &=&  a &&& \alpha_4 = -\alpha_1  \\ \alpha_2 &=& \frac{a^4 + a}{2}= \zeta^2 a &&&  \alpha_5 = -\alpha_2 \\ \alpha_3 &=& \frac{a^4 - a}{2} = \zeta^4 a &&& \alpha_6 = - \alpha_3. \end{array} $$  After all this mess, I have got the automorphisms $\sigma = (12)(45)(36)$ and $\gamma = (135)(246)$. We check that $\sigma\gamma = \gamma^2\sigma$. $\sigma\gamma = (12)(36)(45)(135)(246) = (16)(25)(34)$.   $\gamma^2\sigma = (153)(264)(12)(36)(45) = (16)(25)(34)$ so indeed $\sigma\gamma = \gamma^2\sigma$. Hence the Galois group has elements  $$\{1,\gamma,\gamma^2,\sigma,\sigma\gamma, \sigma\gamma^2\} = \{1, (135)(246),(153)(264),(12)(45)(36),(14)(23)(56),(16)(34)(25)\}.$$


Taylor series coefficients of general rational function

Given two (possibly infinite) sequences of complex numbers $\{a_1, a_2, \ldots\}$ and $\{b_1, b_2, \ldots\}$, I'm looking to find a closed form expression for each element of the sequence of complex numbers $\{c_1, c_2, \ldots\}$ where the sequences are related by  $$\frac{1+\sum_{n=1}^\infty a_n x^n}{1+\sum_{m=1}^\infty b_m x^m} = 1+\sum_{r=0}^\infty c_r x^r\,.$$  Essentially, I am looking for a rapid computational algorithm to find the Taylor series expansion coefficients of a general rational function.    Edit: The problem can be simplified to finding a series expansion of $(1+\sum_{m=1}^\infty b_m x^m)^{-1}$ since then the $c$ coefficients are given by the series product.


Making a non-diagonalizable matrix diagonalizable with an small perturbations

For arbitrary non-diagonalizable square matrix $J$, can we always find a arbitrarily small perturbations matrix $\varepsilon A$ that $J+\varepsilon A$ is diagonalizable?  Using Jordan form as following, we can obtain that arbitrarily small pertubations matrix following a certain structure can make a matrix diagonalizable. But can we relax the form of the pertubations matrix?    Give any $J$, let $B$ be the Jordan form. That is, $J=U B U^{-1}$. For a pertubations matrix $\frac{1}{k} U\Delta U^{-1}$ where $\Delta$ is a diagonalizable matrix with different diagonal value, $J+\frac{1}{k} U\Delta U^{-1}$ is diagonalizable.   Can we relax the form of the pertubations matrix?


Brand name as keyword for a brand.com site. How to make it appear in search?

I am working on a website for a client, and even though the site ranks extremely well for various different keywords (which is good), if I search for the site's name the homepage does not appear even on the second page on Google. I have to add the .com so it will appear.  But, for big brands like Best Buy, Nike and millions of others it is enough to just search for the brand itself and the first or second suggestion on Google is the brand's homepage.  How can I raise my brand's authority in Google so it will appear in Google on the first page when some searches for it?  I have tried changing the breadcrumbs so instead of "HOME" it is now the brandname, linked to the homepage. I thought that it will help with internal linking if the anchor text is the brand's name instead of the word "HOME".  Any ideas please?


Vim automatically removes indentation on Python comments

I'm using Vim and editing Python scripts.  Autoindent works pretty well in general, but when I start a new line and type '#' to type a comment, Vim unindents that line for me.   For example, if have  def foo():   and I press enter, Vim will indent properly  def foo():     pass   but, if instead of typing pass, I type #, it unindents automatically  def foo(): # comment  class Thing():     def __init__(self):          pass # comment line gets unindented all the way   my .vimrc file follows.  anyone know why this is happening?  set tabstop=4 set smartindent set shiftwidth=4 set expandtab set backspace=indent,eol,start set scrolloff=3 set statusline=%f%m%r%h%w\ [%Y\ %{&ff}]\ [%l/%L\ (%p%%)] set laststatus=2


JavaScript function inside simple for loop

I got stuck on a really simple task. I have several JavaScript function, but I am bad at JS so cannot solve this. I need to put it inside the for loop. Please help. My solution doesn't work. The logic is down - my code is awful help.  FUNCTION WITHOUT LOOP  <script> var c1 = 14.94; var c2 = 12.20;  function changeq() {     var q1 = parseInt(document.getElementById('q1').value);     var t1 = q1 * c1;     var total1 = t1.toFixed(2);     document.getElementById('ukupno1').innerHTML = total1; }  function changeq(2) {     var q2 = parseInt(document.getElementById('q2').value);     var t2 = q2 * c2;     var total2 = t2.toFixed(2);     document.getElementById('ukupno2').innerHTML = total2; } </script>   FUNCTION INSIDE LOOP - WRONG   <script>     var c1 = 14.94;     var c2 = 12.20; var fncs = []; for (var i = 0; i < 3; i++) { funcs[i] = (function(index) {     return function changeq[i] {     var q[i] = parseInt(document.getElementById('q[i]').value);     var t[i] = q[i] * c[i];     var total[i] = t[i].toFixed(2);     document.getElementById('ukupno[i]').innerHTML= total[i];     }     </script>


How to find an open function which is not continous?

So i know that an open function is a function with the property that it sends an open interval to an open interval , but how to find a function which is open and not continous ?  Any hints ?  thanks


Getting error while installing Pop OS [Ubuntu to Pop OS]

I am getting errors while installing Pop Os from Ubuntu. Error while adding repository: sudo add-apt-repository ppa:system76/pop Err:22 http://ppa.launchpad.net/docky-core/ppa/ubuntu focal Release  404  Not Found [IP: 91.189.95.83 80] Err:23 http://ppa.launchpad.net/enso-os/panther-launcher/ubuntu focal Release   404  Not Found [IP: 91.189.95.83 80] Reading package lists... Done N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'http://apt.postgresql.org/pub/repos/apt focal-pgdg InRelease' doesn't support architecture 'i386'  Error while updating sudo apt update Err:22 http://ppa.launchpad.net/docky-core/ppa/ubuntu focal Release   404  Not Found [IP: 91.189.95.83 80] Err:23 http://ppa.launchpad.net/enso-os/panther-launcher/ubuntu focal Release   404  Not Found [IP: 91.189.95.83 80] Reading package lists... Done                       N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'http://apt.postgresql.org/pub/repos/apt focal-pgdg InRelease' doesn't support architecture 'i386' E: The repository 'http://ppa.launchpad.net/docky-core/ppa/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://ppa.launchpad.net/enso-os/panther-launcher/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.  Error while installing sudo apt install pop-desktop.  trying to overwrite '/usr/lib/gnome-initial-setup/vendor.conf', which is also i n package gnome-initial-setup 3.36.2-0ubuntu1 dpkg-deb: error: paste subprocess was killed by signal (Broken pipe) Errors were encountered while processing:  /var/cache/apt/archives/pop-gnome-initial-setup_3.36.1~1593716052~20.04~e07a263 _amd64.deb  What's the solution???


ionBlur Event: Detect the element that is receiving the focus

From a custom directive, I want to determine what is the element that is receiving the focus when a blur event occurs:  @Directive({   selector: '[my-directive]',   host: {     //...     '(ionBlur)': 'onBlur($event)'   } }) export class MyCustomDirective implements OnInit {     //...     onBlur($event) {         console.log(event) // This logs a CustomEvent that contains information only about the element that losing the focus         console.log(event.relatedTarget) // This logs undefined     }     //... }   I am using this directive with an ion-input element:  <ion-input my-directive></ion-input>   When testing, the event parameter of the onBlur method contains the attributes target and currentTarget which both are the element that is losing the focus, but the event.relatedTarget was undefined:    Is it possible to have the element that is receiving the focus too?


Reverse-search in CLI: messed up output afterwards

See my edit below, this is not totally a duplicate of   My reverse-search function in the CLI is broken and I don't know how to fix it back...  When I hit ctrl+r and search a command I did earlier, find it then press the right arrow key to use it, the output is broken. Here is an example:  # I reverse-searched the word "test" then pressed right arrow yoshiji@x1carbon:~/path/to/git/folder (master) $ch)`test': rake test #                                              ^^^^^^^^^^ weird output #                                                     ^ cursor right there   It also "shifts" my cursor to a different position. If I press enter, the right command is executed (rake test in this case) so it means the text displayed is not the same as what is actually executed.  I know this is most-likely related to my PS1 export in my ~/.bashrc, so here are the last lines of this file:  # Git branch in prompt. git_branch() {   branch=$(__git_ps1 2> /dev/null)   if [ "$branch" = " (master)" ]; then      echo -e "\033[33m${branch}\033[00m" # yellow   elif [ "$branch" = "" ]; then      echo -e "\033[90m (no git)\033[00m" # red   else      echo -e "\033[32m${branch}\033[00m" # green   fi } PS1='\u@\h:\w$(git_branch) \$ '   This is something I wrote to displays the git branch in orange (if master branch) or else in green (or no git in gray).  Do you guys have any idea on what is causing this weird behavior?    Edit: This is a different problem from the  in the way that I am using echo -e "some string" to return a string having color+name of the git branch from the function git_branch(). Using echo -e does not escape the characters \[ and \] (try it yourself in your CLI: echo -e "\[\033[33m\]test").  Ideally, I would like to keep those conditional colors based on the branch's presence & name (gray if no branch, orange if master, else green).


Is investing in index futures better than investing in index funds?

Given that futures price is equal to S*e^(rt), it is possible to create a synthetic investment into an index by:  entering into an index future for the amount of money which are planned to be invested into an index investing this money into a risk-free bond with the same duration as the future (or just keep it in a deposit in a bank)  When such future expires, a new future can be entered into. I see the following advantages of such strategy compared to buying an ETF:  No need to pay an ETF's issuer's commission. This might not be a big deal for investors from the US, because there are funds with a low commission, but in my country (Russia) index ETFs take 0.6-1% as a commission ETFs' price follows the index only approximately, which is not true for futures More liquidity. Suppose you want to cash out part of your investment. In this case, you can just take the money you have on your deposit instantly and cancel out part of future position by shorting instantly. In case of ETF/stocks, you would first sell them, then wait for the settlement, then wait for the funds to be transferred to your account Ability to take more risk if you'd like to. For instance, instead of buying the government's bonds, it is possible to invest into A+ bonds and earn higher interest Margining for a risk-free rate. If you'd like to make do some trading parallel to investing, you can use the money not for risk-free bonds, but for buying stocks, which is much cheaper than what brokers charge  The only disadvantage I see is that you will have to regularly re-enter future contracts, but it doesn't seem as a big disadvantage to me. Yet, future investing doesn't seem to be popular. Why? Are there any flows in my logic?


Suppose that $f:[a, b]\rightarrow\mathbb{R}$ is differentiable and $c\in[a,b]$. Then show that there exists a sequence $\{x_n\}$, $x_n\neq c$, such that  $$f'(c) = \lim_{n\rightarrow\infty} f'(x_n).$$  I am lost in knowing how to use this and where to go from here.


Ubuntu won't boot after a file system check

I've got a dual-boot of Ubuntu and Windows and due to some file system inconsistency Ubuntu won't load. It always runs a file system check and then switches to emergency mode. This is a list of errors from the journal:  -- Logs begin at Čt 2016-10-20 16:27:28 CEST, end at Čt 2016-10-20 16:29:24 CEST. -- kernel: Error parsing PCC subspaces from PCCT systemd-fsck[506]: fsck failed with error code 4. systemd[1]: Failed to start File System Check on /dev/disk/by-uuid/115d2332-e953-48a1-a0c8-05fef157d207.   Trying to fix the Error Parsing PCC Subspaces I've disabled hiberboot in Windows but it didn't help.  I've also tried the most voted suggestion in this thread with no success:    Fsck said:   /dev/sda1 clean   Fdisk output:  Disk /dev/sda: 465.8 GiB, 500107862016 bytes, 976773168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0x38034de7  Device     Boot     Start       End   Sectors   Size Id Type /dev/sda1            2048 453787647 453785600 216.4G 83 Linux /dev/sda2       968970238 976771071   7800834   3.7G  5 Extended /dev/sda3  *    453787648 556187647 102400000  48.8G  7 HPFS/NTFS/exFAT /dev/sda4       556187648 968968191 412780544 196.8G 83 Linux /dev/sda5       968970240 976771071   7800832   3.7G 82 Linux swap / Solaris  Partition 2 does not start on physical sector boundary. Partition table entries are not in disk order.   Would you know about any solution to this?  EDIT:  After fsck on sda4, it seems to work fine.  blkid output:  /dev/sda5: UUID="e8f7fdb0-1024-496b-aaba-376aeb30849b" TYPE="swap" PARTUUID="38034de7-05" /dev/sda1: UUID="9fa78f27-9b26-4f92-bd20-180ed6903220" TYPE="ext4" PARTUUID="38034de7-01" /dev/sda3: UUID="249E367E9E364916" TYPE="ntfs" PARTUUID="38034de7-03" /dev/sda4: UUID="115d2332-e953-48a1-a0c8-05fef157d207" TYPE="ext3" PARTUUID="38034de7-04"


What if the whole question is contained in the title? What should I place in the body?


Drawing different circles with intersections

I found the following in this forum:  \def\firstcircle{(0,0) circle (1.5cm)}    \def\secondcircle{(60:2.1cm) circle (1.5cm)}    \def\thirdcircle{(0:2.1cm) circle (1.5cm)}   My goal is to draw three circles with intersections. It works fine. But i do not know why. It's clear what the coordinate (0,0) in the definition of the first circle means.  But how can I interprete (60:2.1cm) or (0:2.1cm)?


Union of all finite fields of order $p^i$, for some prime number $p$ is algebraically closed.

Let $p$ be a prime number. Consider for all $k,r\in\mathbb{N}_0$ with $k|r$ the field $\mathbb{F}_{p^k}$ as a subfield of $\mathbb{F}_{p^r}$. Define $$ \overline{\mathbb{F}_p}:=\bigcup_{i\in\mathbb{N}_0}\mathbb{F}_{p^i}.$$ I want to show that $\overline{\mathbb{F}_p}$ is the algebraic closure of $\mathbb{F}_p$. I already managed to show that $\overline{\mathbb{F}_p}$ is a field and that it is algebraic over $\mathbb{F}_p$, but I can't seem to show that it is also algebraically closed. I know that for every $i\in\mathbb{N}_0$, $\mathbb{F}_{p^i}$ is a decomposition field of the polynomial $X^{p^i}-X$. Which means this polynomial can be expressed as $$X^{p^i}-X=\prod_{a\in\mathbb{F}_{p^i}}(X-a),$$ and I thought that this could help me prove that every irreducibel polynomial in $\overline{\mathbb{F}_p}[X]$ has degree $1$ but so far it hasn't. Any help would be appreciated.


Command calls LuaLaTeX function, backslash in argument

I would like to create a command that simply prints what I give to it, but through Lua. Pointless for now, but I want to expand this to a more complex use-case. I've read a few answers around here, but can't quite figure it out. Simply put, if I give my command hello \bfseries world as an input, I'd like the output to show "hello world". \documentclass{article}  \usepackage{luacode}  \newcommand\mycmd[1]{%  \directlua{tex.sprint("--->".."\luatexluaescapestring{#1}") } }  \begin{document}  \mycmd{Hello world}  \mycmd{Hello \\world} % a bit surprised \\ works, why?  \mycmd{Hello \bfseries world} %  \end{document}


I want to write a recursive function that gives me the lenght of a list. To make it recursive, i use this pointer as default parameter in the declaration of the function in the List class header. But the compiler gives me an error... This is the code:  //Header file #include "Nodo.h"  template < class Tipo >  class Lista {      private:         Nodo< Tipo >* Prox;       public:         Lista();          bool ListaVuota();          int DimensioneLista(Lista<Tipo>* = this);          void InserisciInCoda(Tipo);  };  //CPP file  template< class Tipo >  int Lista< Tipo >::DimensioneLista(Lista< Tipo >* lista)  {      if(lista->ListaVuota())         return 0;     else         return 1+DimensioneLista(lista);  }


Anonymouse users can't see Openlayers Data Overlay

I have a map view displaying the Openlayers Data Overlay. It's displaying a list of GPS tracks from a "Map Feature" content type I made.   Logged in with the Administrator, I can see all the tracks on the map fine. The preview for the Data Overlay shows all the data coming through great.   When I few the map as an Anonymous user, not logged in, none of the GPS tracks show up. The map displays on the page but none of the data from my Data Overlay.  I've looked all over the place trying to find content permissions that are wrong that are screwing things up but I can't find anything.   Why is the data on the map showing for the administrator and not Anonymous users?


Need help with the sum of the binomial coefficients: ${k+l \choose l}$

I am tring to prove the following equality :  $\displaystyle \sum_{k=0}^n {k+l \choose l} = {n+l+1 \choose l+1} $  However, I did not manage to find a proof... Do you have any ideas ?  Thanks !


If $f: G \rightarrow H$ is a surjective homomorphism, $G$ finite, prove the following:  1) If $P$ is a p-subgroup of $G$, then $f(P)$ is a p-subgroup of $H$.  2) If $S$ is a Sylow-p-subgroup of $G$, then then $f(S)$ is a Sylow-p-subgroup of $H$.  EDIT: I have been doing this problem for several days now on and off and I have no idea how to start...I'd rather skip the hints honestly, as I've been given a few and still am missing a key piece.


Series $\frac{x^{3n}}{(3n)!} $ find sum using differentiation

Find sum of the series $$\sum_{n=1}^{\infty}\frac{x^{3n}}{\left(3n\right)!}$$ using differentiation. So far I found that $$S(x)+1=S'''(x)$$ but it does not help. Then I tried different interesting ideas  like $$S(x)+S'(x)+S''(x)=e^x-1\,.$$Maybe if I get the third equation it will allow me to construct a kind of differential equation. Then, by solving it, obtain $S(x)$.


Find the sum $\sum_{n=1}^{\infty} \frac{\ln n}{n(n- \ln n)}$

Find the following sum : $\sum_{n=1}^{\infty} \frac{\ln n }{n(n- \ln n)}$  I couldn't find any way to solve.   I just want a hint, how to initiate?


Today I installed Ubuntu on my Acer E-15. I go on Netflix a lot and need to be able to watch it. I tried to install Wine but for some reason it wouldn't install "Package dependencies cannot be resolved" I also couldn't copy and paste because I can't scroll over text nor right click .  I tried going on Chromium. When I tried to watch a show "This webpage has a redirect loop".  What I am to do?


Is it considered poor form to answer old and inactive questions? (thread resurrection)

I think the title says it all. On some support boards and forums it is considered poor form because it causes activity that bothers some. Especially to those that monitors that site's "newest changes" page.   The behavior is called "" (or "graveyard bumping") and there are even  about it.  If different policies applies to different SE sites, please link to them in your answer.


Why does Careers list "jobs near worcester" on my homepage?

I'm in Bristol, England, and Careers appears to know that (my Profile page shows "Bristol, England"). Whenever I visit the homepage, though, Careers shows a section for "jobs near worcester".  Now, I'm sure Worcester has a lot going for it, but it's a relatively small city more than 50 miles away from where I am, so I'm just curious as to (a) why Careers is so keen to show me jobs near Worcester, and (b) if there's any way of telling the homepage to show me jobs near where I live, instead?  EDIT: I've since checked Careers from work (dangerous!) rather than home and it shows me jobs from London, which is even further away from me. So I guess it's ignoring what I've specified and guessing, wrongly, by IP address.


I am writing a validation rule as follows : AND(NOT(ISBLANK(LookupField__c)), checkField__c )  The above works fine and have no issues, but when I change it to as follows : AND(NOT(ISNULL(LookupField__c)), checkField__c ) the validation fails.  I observed that when I having ISNULL, even if the lookup field has no value its evaluated to false, does in turn evaluating to TRUE due to NOT check. Not sure why this is happening and what is the difference in evaluation of same criteria with ISBLANK since that works fine.


We've been out of private beta for only two days, and stackoverflow.com is already ranking high in .  Are there any specific techniques applied in the site? I've been researching the subject for some time and haven't found it to be so easy.   even returns site-links.  ()


Let $\{a_n\}_{n=1}^{\infty}$ be a sequence such that every subsequence has a subsequence that converges to $L$. Then, $\lim_{n \to \infty} a_n = L$.

So, here's the full question: Let $\{a_n\}_{n=1}^{\infty}$ be a sequence of real numbers. Suppose that every subsequence of $\{a_n\}_{n=1}^{\infty}$ has a subsequence that converges to a real number $L$. Prove that $\lim_{n \to \infty} a_n = L$.  Proof Attempt: To prove this, let us define our terms very carefully. Let $\{a_n\}_{n=1}^{\infty}$ be the main sequence we are considering. Let $\{n_k\}_{k=1}^{\infty}$ be a strictly increasing sequence of natural numbers and let $\{k_m\}_{m=1}^{\infty}$ be a strictly increasing sequence of natural numbers as well. Now, let $\{a_{n_k}\}_{k=1}^{\infty}$ be a subsequence of the main sequence. By hypothesis, this subsequence has a subsequence that converges to $L$. Let's denote this particular subsequence by $\{a_{n_{k_m}}\}_{m=1}^{\infty}$. By the definition of convergence, for any $\epsilon > 0$: $$\exists M \in \mathbb{N}: \forall m \geq M: |a_{n_{k_m}}-L| < \epsilon$$ Since $\{k_m\}_{m=1}^{\infty}$ is a strictly increasing sequence of natural numbers, we note that: $$\forall m > M: k_m > k_M$$ Let $K := k_M$. Then: $$\exists K \in \mathbb{N}: \forall k \geq K: |a_{n_k}-L| < \epsilon$$ This follows directly from the previous statement we made. If $m \geq M$, then $k_m \geq k_M = K$. Then, since $\{n_k\}_{k=1}^{\infty}$ is also a strictly increasing sequence of natural numbers, for all $k \geq K$, $n_k \geq n_K$. Define $N = n_K$. Then, we can finally see that: $$\exists N \in \mathbb{N}: \forall n \geq N: |a_n-L| < \epsilon$$ That is precisely the assertion that $\lim(a_n) = L$. That proves the desired result. Is the proof above correct? If it isn't, why? How can I fix it? Edit 1: Suppose that $\{a_n\}_{n=1}^{\infty}$ does not converge to $L$. It either converges or it diverges. If it converges, then it converges to some real number $M \neq L$. So, every subsequence of this sequence converges to that same real number. So, every subsequence of each subsequence must also converge to $M$. That's a contradiction. If it diverges, then: $$\exists \epsilon > 0: \forall N \in \mathbb{N}: \exists n \geq N: |a_n-L| \geq \epsilon$$ Define the set $S = \{n \in \mathbb{N}: |a_n-L| \geq \epsilon\}$. I claim that this set is infinite. If it were finite, then we would just define $N = \max(S) + 1$. So, for any $n \geq N$, $|a_n-L| < \epsilon$ and the sequence converges. That would contradict our assumption. So, $S$ has to be infinite. (Uhhh not really sure where to go from here?) Edit 2: I'm not quite sure why this question was closed. Even though the statement I'm proving has been posted by others, this is my version of the argument and a whole separate discussion on the specific thought process that I used. Surely it might have some value for the individual stumbling on this site. Besides, the question I asked was specifically a solution verification. All my questions have been of that nature and I don't really understand why that's an issue.


I'm working on Project Euler, :     The series, 11 + 22 + 33 + ... + 1010 = 10405071317.      Find the last ten digits of the series, 11 + 22 + 33 + ... + 10001000.   This would be the equivalent of: $$ f(n) = \sum_{i = 1} ^ n i^i $$  The original question aside, it got me thinking. The rate of change from n to n+1 would be i^i, so if I could take the integral of ii, I could get a generalized formula for any given n. Upon plugging it into Wolfram Alpha, I got a monstrous expansion, but it said, "no result found in terms of standard mathematical functions". It's been years since I've taken calculus and I'm mostly a computer science guy to begin with, but is this premise sound? And if not, where did I go wrong?


Looping over charts and names simultaneously

I want to use a common index to loop over two separate comma-separated lists at once, one which is a list of abbreviations and one a list of names.  I want to use the abbreviations to import charts as pdfs, and the names to label them.    This is what I have so far:  \documentclass[12pt]{article} \usepackage{tikz} \usepackage{graphicx}  \def\namelist{"New York", "Illinois","Texas"} \def\abrevlist{NY,IL,TX}  \begin{document}  \foreach \x in \abrevlist {%     \newpage     \section*{\x}  % <-- I want to use the state name here          \begin{figure}[h!]         \includegraphics[width=.5\textwidth]{../charts/summary/\x _compare.pdf}         \caption{\x}  % <-- I want to use the state name here         \end{figure}  } \end{document}   This imports the figures as I want, but does nothing with the state names.  I would like to replace the section and captions with, for example, "New York" in place of "NYC".    Obviously, one could create an index \i and loop over that to index the abbreviation or name as necessary.  But I can't make that work.  Any suggestions?  Thanks!


Need help with some equivalent statements of measurability

I want to know why the above statements are true. Thank you!


I have a script that enables artists to edit their profile. One thing is proving to be a problem. I cannot how to sanitize what the user has entered. Everytime a ' is put in the data is not shown as it cuts the php short.   Here is my form for bio:  username = $_SESSION['username'];     $pass = $_SESSION['password'];     include ("../database.php");    $result = mysql_query("SELECT * FROM members WHERE username='$username' AND     password='$pass' AND artist='Y'");  while($row = mysql_fetch_array($result)){         echo '
<form action="phpscripts/artistupdate.php" method="post">        <textarea name="bio" rows="10" cols="80" name="bio" value="'. $row['bio']. '" class="bio">'. $row['bio']. '</textarea>

<t1>Everything is still in the beta stage so there are bound to be a few problems. If you spot one please tell us about it.</t1>

';   Here is the script that uploads to database;  $username = $_SESSION['username'];      $pass = $_SESSION['password'];       $artistname = $_POST['artistname'];      $bio = $_POST['bio'];     include ("../database.php"); mysql_query("UPDATE members SET  bio='$bio', artistname ='$artistname' WHERE username='$username' AND password='$pass'  AND artist='Y'");  $artisturl = mysql_query("SELECT * FROM members   WHERE username='$username' AND password='$pass'  AND artist='Y'");  while($row = mysql_fetch_array($artisturl)){ if (isset($_POST['submit'])) {header("location:../artists/artist.php?    artist=".$row['artistname']."");} }  } else echo'<p1>You must be an artist to use these features.</p1>';   Yes, I am aware i need to upgrade to mysqli and I am aware I need to use prepared statements. Need to sort this out first though.


What's the possibility of adding a "Did you mean ..." in the tagging system?

On some sites, and especially with new users, the format and function of the tagging system might be a bit unclear, so often tags get used incorrectly.  For example, one such issue on Arqade is the tag  - new users often type instead, something like fallout shelter ending up with the tags  and  - both of which (on Arqade) are legitimate tags, for two completely different games, and different again from the intended one.  My current understanding of how the tagging is managed is non-existent, so my suggestion might not even be possible, but what is the likelihood of adding a "service" that might detect this, and suggest the correct tag? maybe something like      Did you mean ?   To perhaps further explain, or refine my idea, some sites offer a tag suggestion, that it picks up from the text in the question (as described above). Another part of that could possibly look at the tags you are using when you ask a question, compare them (possibly by looking at the tag wikis), and suggest an alternative, based on the suggested tags, the tags used, and the similarities between the two.


Is the Microsoft.VisualBasic namespace "true .NET" code?

My dev team is getting ready to start a new project. The shop has been a "VB shop" since the days of VB3, but the prevailing opinion now is that we're a ".NET shop" and since C# was created specifically for .NET, whereas VB.NET was a retrofit, we've decided to move forward writing C# only. The controversy revolves around the question of whether the Microsoft.VisualBasic namespace has a legitimate place in new development or if it is only for backward compatibility for VB6 (and older) code. A further, and more interesting question is whether the code "under" the Microsoft.VisualBasic namespace is even .NET code of if it is really the old VB runtime carefully packaged in a .NET wrapper, making it in fact a COM interop control (similar to how WinForms wraps the non-.NET Win32 windowing API but exposes only .NET APIs for consumption).  To make this even more confusing, our dev team has a Microsoft Consulting Services consultant telling us Microsoft no longer supports Visual Basic, including the VB runtime underlying the Microsoft.VisualBasic namespace.  What I'm looking for are links -- preferably to unimpeachable Microsoft sources -- to documentation that definitively answers this question one way or the other. I've already tried several search permutations on Google and not gotten any closer to getting to the bottom of this question.  EDIT: Apparently I didn't make my question clear. I'm not asking if VB.NET is true .NET code. I'm trying to determine if whatever is "under" the Microsoft.VisualBasic namespace is .NET code or if it's the old VB6 runtime carefully packaged and exposed as .NET code. Someone already said that 9/10 of the namespace simply wraps code from elsewhere in .NET; what about that other 1/10?


I had a test today and there was this question : If you are a well-organized person, you .... your time.   a) will manage b) manage   I'd like to know the answer and why?   Thanks in advance.


What is the method of attraction between two sheets of material with a fluid in between

If you take two sheets of finished metal for example and put oil between them they are almost impossible to separate perpendicular to the contact plane. Sheets of glass and water have the same property.   What is the reason for this attraction? Van der Waal, surface tension, suction, or some sort of adhesion of thin films? I have tried researching this based upon those topics, but can't seem to find any information that shows a definite relationship.  Thanks!


I clicked Multiplayer, click join server(Hypiexl Network, us.hypiexl.net). Minecraft will show me 'Connecting to the server...', then it will show:  io:netty.ConnecTimedOutException: Connection timed out  I use Minecraft Java Edition 1.14.4 on a Mac. My Java is the lasted version JRE 8. My firewall is off. Can anyone help me?


How do I show this fourier series relationship?

I want to show that $$\int^a_0\sin(mx)\sin(nx)\ dx = 0$$  for $m, n$ positive integers and $m\neq n$, and $a = k\pi$, i.e. the integer multiple of $\pi$.  I have tried expressing the equation in a fourier series:  $$f(x) = \frac{a_0}{2} + \sum^\infty_1 a_n \cos(n\pi x)$$ since the equation is an even function. However, I'm unable to show that $f(x)$ is equivalent to zero in the interval mentioned. I can reason that for half wavelengths, the summation should end up in zero because of how the cosine wave is like. But how do I remove $a_0 /2$?


I can't come up with an idea on why the array is printing out the int's in order instead of the order that they're put in the array.   int[] array = {1, 4, 0, 3, 2}; for(int i : array){         System.out.println(array[i]); }   Is there any explanation of this?  Thanks in advance!


When I try:     Wood plank | stick | wood plank -------------------------------   wood plank | stick | wood plank     in the crafting bench, it doesn't work.


How is it possible in Eclipse JDT to convert a multiline selection to String. Like the following  From:  xxxx yyyy zzz   To:  "xxxx " + "yyyy " + "zzz"   I tried the following template   "${line_selection}${cursor}"+   but that way I only get the whole block surrounded not each line separately. How can I achieve a multiline processing like commenting the selected block?


OSX 10.8 - How to keep a custom dock for all users that login

I have an iMac with OSX 10.8, joined to a work domain. I want to get create a custom dock and save it so all users will see my custom dock when they log in. I've done some Google searches and everything seems to point to these steps:   Create dock how you want it Copy ~/library/preferences/com.apple.dock.plist to /system/library/user\ template/english.lproj/library/preferences   I've done this and then logged in as a new user, but am seeing a different dock than I created. I've also tried copying com.apple.dock.db to English.lproj/library/preferences as well, but to no avail.  The new users that will be logging in are network accounts.  Am I missing something?


My country of origin is India. I want my parents to pay me a visit in Canada. I am a permanent resident here.  Problem:  My father is a self-employed businessman and so I'm not sure about the documents about his business. From what I have googled they say you should give reasons why you want to go back.  His annual income as per ITR is 550,000 rupees.  He doesn't have a business registration as it's a small business. But he has a website, trademark information, enough bank balance, a current account etc.  My mother is also self-employed but she has a boutique and again she doesn't have any business registration or any solid proof. Her annual income as per ITR is 500,000 rupees.  Worst part: My parents already have 2 USA rejections in their history of tourist visas.  So, can anyone suggest something? I don't want them to face another rejection because I want them to come here.


Is "ln" (natural log) and "log" the same thing if used in this answer?

Find $x$ for $4^{x-4} = 7$.  Answer I got, using log, was ${\log(7)\over 2\log(2)} + 4$  but the actual answer was ${\ln(7)\over2\ln(2)} + 4$  I plugged both in my calculator and turns out both are the equivalent value.  Anyways, is using either one of ln or log appropriate for this question? Obviously ln is when log has the base e, and log is when it has the base 10.   Final question: How do I know when to use which? that is which of ln or log is used when solving a question??  For example, if a question asks to find $x$ for $e^x = 100$, I will use $\ln$ since $\ln(e)$ cancels out.  If a question asks to find $2^x = 64$, i will use log since "$e$" isn't present in the question.  So is using either $\log$ or $\ln$ the same?


If $A$ and $B$ are square matrix such that $AB=I$ then $BA=I$ too.

If $A$ is a square matrix which coefficients are the scalar of a field $\Bbb K$ then there exist a linear function $f:\Bbb K^n\rightarrow\Bbb K^n$ such that $$ f(e_j):=A_j $$ where $A_j$ is the $j$-th column of $A$ for any $j=1,...,n$. Then if $I$ is the identity square matrix if $A$ and $B$ are two square matix such that $AB=I$ then there exist two function $f,g:\Bbb K^n\rightarrow\Bbb K^n$ such that the identity square matrix is the matrix of the function $(f\circ g)$ and this means that $(f\circ g)$ is the identity on $\Bbb K^n$. So to prove the statement of the question I have to prove that $(g\circ f)$ is the identity too. So how prove the statement? Could someone help me, please?


If three cards are drawn randomly from a normal playing deck without replacement, what is the probability that two end up being black and one red? I did the problem and came up with 13/102. My Saxon book said 39/102 or 13/34. They got that by adding together the probabilities of the three color combinations, which are all equal to each other. But I don't care what order I draw those colors in. Why do they add together those three events when I only draw the three cards once?


Place image in top of page of book document

I need to place an Image in top of book document. But thats image still placed in center document. This is my code:  \documentclass[oneside,a4paper  , 12 pt]{book}  \usepackage{graphicx} \usepackage{caption} %\usepackage{package} \usepackage[space]{grffile}  \begin{document} \begin{figure}[t!] \centering \includegraphics[width=0.7\linewidth]{E:/gambar tesis/variasi/9-2-10-cheek-kiss} \caption{} \label{fig:9-2-10-cheek-kiss} \end{figure}  \end{document}


If there is friction and everything stops on earth why does earth not stop due to friction?

Why do planets revolve around the Sun if there is a force called frictional force? Why do planets not stop rotating while the objects in motion stop after a while? Why are they continuously moving? Why are planets not affected by frictional force?


What's the best way to deactive my adblocker for Stack Exchange?

Ironically,  convinced me to make the Stack Exchange network the only place where my adblocker is deactivated. However, that's easier said than done. I can whitelist *.stackexchange.com, but that misses quite a number of sites:               Maybe more? Also, even if I added a rule for all, there could still be more in the future.   So how can I whitelist all Stack Exchange sites in a future-proof and complete way? Is there some common property of all these sites that I can use, maybe the host?  I'm using the Chrome extension , but a general solution that works for many different adblockers would of course be very welcome.  Apart from that, I also have an issue with wildcards in general, but that's something to ask in the AdGuard forum.


Multiple Installations and Understanding $PATH

I have an older version of Git installed at:  /usr/bin/   I recently downloaded a newer version to:  /usr/local/bin   When I type:  which git   I get the location of the old version. I believe that this is just because /usr/bin/ appears before /usr/local/bin in my $PATH variable and so the older version of git is 'found' first.   To test this, I renamed the older version of git to "git_old". Now when I type:  which git   I get the location of the newer version, as expected. But when I type:  git --version   I get the following error:  -bash: /usr/bin/git: No such file or directory   I'm just wondering why my computer is going back to looking in the old location for Git?


Intuition for a proof that the rationals are incomplete.

Let A be a set of positive rationals $p$ such that $p^2<2$. Now this set contains no upper bound. To prove this, for every rational $p$, a number $p- \frac{p^2-2}{p+2}$ is associated. This number (let's call it $q$) is greater than $p$. Also, it can be proved that $q^2<2$. Now the proof is complete.    I don't know if this is the only proof of this theorem but anyway how could one come up with that number to be associated with $p$. I am interested in the thought process behind.


Hello i am trying to add my Class's objects into an ArrayList with the objects attributes but i keep getting null pointers I am reading values from a txt file assigning them to the attributes and then put the object into the array list  here is my code  public class Users { Scanner scan; BufferedReader reader; MainGui gui; Login login; String name; String surname; String dob; String address; String town; String number; String position; ArrayList<Users> allUsers = new ArrayList<Users>();   public Users(Login login){      this.login = login;   open(); }  public void open(){   try {     URL path = Users.class.getResource("records.txt");     File f = new File(path.getFile());     reader = new BufferedReader(new FileReader(f));     scan = new Scanner(reader);     } catch (FileNotFoundException e) {     System.out.println("File not found");     } }  public void readRecords(){  open();  while(scan.hasNext()){      Users user = new Users(login);      user.name = scan.next();      user.surname = scan.next();      user.dob = scan.next();      user.address = scan.next();      user.address = addSpace(user.address);      user.town = scan.next();      user.number = scan.next();      user.position = scan.next();      allUsers.add(user);  }  scan.close();  }   public void printUsers(){    readRecords();      for(Users user : allUsers){      System.out.println("" + user );    }    }  }   I have included all the methods playing part in this in order for you to help me better.


Let $K$ be a normal subgroup of order 2 in group $G$, show that $K$ lies in the centre of $G$. Describe a surjective homomorphism of the orthogonal group $\mathrm{O}(3)$ onto $C_2$ and another onto the special orthogonal group $\mathrm{SO}(3)$.


Why do people vote more on answers than questions?

I noted a fact on Stack Overflow badges.  ● Nice Answer  × 39355 ● Nice Question × 7601   (5.2:1 rate)  ● Good Answer  × 6433 ● Good Question × 1199   (5.3:1 rate)  ● Great Answer  × 712 ● Great Question × 105   (6.8:1 rate)  All in all, since the badges are awarded for the same amount of accumulated votes in each category, it appears that people tend to vote more for the answers than the questions...  Just a thought...


How to customize the edit form for a content type

I would like to customize the edit form for creating new content. For example, I create a new content type named Experiment and I want to change the layout, add text and style the edit form. What is the best approach?


simple if, else if .cannot get it to work

im trying to make a small program that asks for a number between 1-10 and then gives out a different prewritten response. this is what i have so far.  import java.util.Scanner; public class AlasFutureTeller {         public static void main(String [ ] args)     {         System.out.println("I CAN READ YOUR FUTURE!");         System.out.println("TYPE A NUMBER BETWEEN 1 AND 10 TO MEET YOUR FATE!!");         Scanner oneTen = new Scanner (System.in);         int one == oneTen;         if (oneTen=="one")             System.out.println("YOU WILL GO TO SLEEP TODAY!!");         else if ( oneTen=="two")             System.out.println("YOU WILL HAVE A BIRTHDAY EVERY YEAR UNTIL YOU DIE!!");         else if ( oneTen=="three")             System.out.println("YOU WILL SHOWER SOMETIME IN THIS YEAR!!");         else if ( oneTen=="four")             System.out.println("YOU WILL LIVE UNTIL YOU THE DAY YOU DIE!!");     } }


Integrate close and delete votes into /review

It's recently been mentioned in some chat conversations that low-reputation close flags are given too high an importance for moderators and should be directed to the community instead. It's been suggested that on Stack Overflow, close flags should go to the 10k queue rather than the mod queue (this may in fact already be implemented).  While I don't entirely disagree with this, I think it only speaks to one head of a two-headed problem. The more pressing issue - especially on Stack Exchange sites, as opposed to the trilogy - is that close votes don't reach the moderators often enough.  On a site like Programmers.SE, for instance, where there are still a lot of historical questions that need to be cleaned up or closed - it's almost pointless to cast a close vote because no one will ever see it. Better to just flag for moderator attention and not waste your vote (and get some of those lovely flag weight points while you're at it).  One suggestion was to have the first close vote on a question automatically generate a mod flag. This was fairly criticized as creating more work where there should be less.  However, the basic principle of the idea makes sense; diamond moderators and privileged users should have some way to be aware of new close votes, just in case the rest of community isn't pulling its weight.  So a better (IMO) proposal is to turf the near-useless "10k tools" close/delete pages and integrate their content into /review. This would give moderators (as well as privileged users) the ability to review close votes, on sites that need it (such as P.SE), without forcing them into an unwanted workflow on sites that don't (such as Stack Overflow). This also has the advantages of:   Showing an excerpt and tags along with the question titles; Reducing overall clutter (the 10k page is pretty noisy with all its sections); Displaying many more questions at once (/tools seems to have a max of 30, expanded); Giving a realistic indication of how much material there actually is to get through; Embedding action links (e.g. flag/close/delete); Seamless integration of close votes and close flags in a meaningful area; Generally giving reviewers the feeling that they're actually making progress.   It would also be incredibly useful if moderators in particular could dismiss questions from the closed/deleted review just like they can dismiss flags, in effect saying "I don't care, let the community handle this one."  Questions would appear in the closed/deleted review page after the first close vote occurs, and then sorted either by the time of that vote or by the total number of votes (or both). Dismissing (if implemented) would dismiss it permanently, ignoring any new votes, until the question is closed or reopened. Straightforward process with minimal noise.  Bottom line: I think that the /review pages encapsulate a pretty good workflow, and it's a shame that critically-important information is still being jammed into the old /tools clunker when we already have something so much better. My responsibilities as a moderator and/or a 10k user would be a whole lot easier if I could review close and delete votes through /review.


How can i convert this string  t     10/04/2017 16:10:43   to a DateTime value?  DateTime.Parse() didn't work.


ETL: extracting from 200 tables - SSIS data flow or custom T-SQL?

Based on my analysis, a complete dimensional model for our data warehouse will require extraction from over 200 source tables. Some of these tables will be extracted as part of an incremental load and others will be a full load. To note, we have about 225 source databases all the with the same schema. From what I've seen, building a simple data flow in SSIS with a OLE DB source and OLE DB destination requires the columns and data types to be determined at design time. This means that I will eventually end up with over 200 data flows just for the extraction alone. From a maintainability perspective, this strikes me as a big problem. If I needed to make some kind of sweeping change to the extraction code, I would have to modify 200 different data flows. An an alternative option, I wrote a small script which reads the source databases, table names and columns I want to extract from a set of metadata tables. The code runs in multiple loops and uses dynamic SQL to extract from the source tables via a linked server and OPENQUERY. Based on my tests, this is still not as fast as using an SSIS data flow with an OLEDB source and destination. So I am wondering what kind of alternatives I have. Thoughts so far include:  Using  to programatically generate SSIS packages with simple data flow. The tables and columns to extract would come from the same metadata tables mentioned earlier. Purchase 3rd party software (dynamic data flow component)  What is the best way to approach this? When it comes to .NET programming I'm a beginner, so the time required to ramp up just with the basics is also a concern.


Is there a rule of thumb for RAM upgrades?

I'm having a hard time figuring out whether or not a certain laptop/computer's RAM can be upgraded or not.  Is there a rule of thumb that determines how much max RAM one could add to a system without looking it up via external websites?   A little bit of a background information: I work in computer sales at a computer electronics store, so it is virtually impossible for me to install any sort of software that would detect computer specs, and I get a lot of customers who wonder what laptop/desktop RAM upgrades usually are.  It's frustratingly annoying to have to constantly search the web for information.  Is there a certain rule that adding more RAM entails? Does it make a difference if it's a 32-bit or 64-bit machine? Are other factors, such as the OS, hardware, and other things matter?


In a relatively short time period I will finally embark on all-grain brewing. I would rather purchase grains online as it is cheaper than the LHBS, but the LHBS won't let me use their crushing equipment unless I bought the grains from them.  I was hoping that there was some hard and fast rules regarding this, like "after 3 days, crushed grains start to lose potency; after 10 days, throw them out."  Does this time frame depend on the type of grain, or are they all about the same?  Is there any (relatively) non-anecdotal evidence in this regard? I.e. did anyone ever purchase 10 pounds of one grain, crush 5 pounds, and brewed n many days later? (Double blind taste tests preferred)


I have a directory with *.txt files.   How can I list the txt filenames that are still having non-unix eol's? So windows and mac eols.


I've advanced to Arena 2, but I don't see an option to go back to previous arenas in order to continue collecting the previous chests. How can I go back to previous arenas? If it's not possible, how can I collect the cards from the previous arenas?


Derivable product of derivable and non-derivable function, not satisfying product rule

Are there functions $f, g : \mathbb{R} \to \mathbb{R}$ satisfying the following:   $f(0) = g(0) = 0$,  $f'(0)$ and $(fg)'(0)$ are defined, but $g'(0)$ is not defined, $(fg)' \neq 0$     If both functions were required to be derivable, there is no such example (due to the product rule). If neither is required to be derivable, we can take $|x|$ and $sgn(x)$. But what if one is derivable and the other is not?


Ubuntu point release 18.04.01 is . But when trying to update my 16.06 server nothing is not found, only the 18.04 is found when passing the dev option to the do-release-upgrade command:  [12:10:04] root:~# do-release-upgrade --check-dist-upgrade-only Checking for a new Ubuntu release No new release found. [12:10:06] root:~# do-release-upgrade --check-dist-upgrade-only --dev Checking for a new Ubuntu release New release '18.04 LTS' available. Run 'do-release-upgrade' to upgrade to it.   Am I missing something? Or it's just not available for now for servers?


I found two very useful posts about the difference between linear regression analysis and ANOVA and how to visualise them:      As stated in the first post, to test whether the average height of male and females is the same you can use a regression model ($y = \alpha + \beta x + \epsilon$, where $y$ denotes height and $x$ denotes gender) and test whether $\beta = 0$. If $\beta = 0$, then there is no difference in the height between males and females. However, I am not quite sure how this is tested when you have three groups. Imagine the following example:  height (y) -  group (x) 5          -  A 6          -  A 7          -  A 6          -  A 30         -  B 32         -  B 34         -  B 33         -  B  20         -  C 19         -  C 21         -  C 22         -  C   The regression model would look like:  $$y = a+ b x + \epsilon$$  I quickly visualized the data (see image below)  They way I understood the regression model is that it would now test whether any of the three slopes (AB, AC or BC) has a slope $b$ which is significantly different from 0. If that's the case one can conclude like in an ANOVA that there is at least one group in which height is significantly different from one or more groups. Afterwards, one could use a post-hoc test of course to test which of the groups really differ. Is my understanding of how the regression models tests this hypothesis correct?


I installed Blender for a project working on and it's way more than I need. I'd like to uninstall it, but can't figure out how to do so. It's not showing up in Programs (using Windows 9) and I can't find instructions on how to remove it in the Blender documentation. Any assistance would be greatly appreciated. Thanks.


Repeating (or not) "to" in a sentence involving infinitives set in parallel

I googled it but I couldn't find the answer... maybe I didn't seek it in the proper way. My question is if "to" must be repeated in sentences such as the following ones:   In the past, women used to do the housework and to take care of children.  The aim of this meeting is to control their progress and to discuss the new working plan.    If I had to bet, I would omit the second to... But I am not sure about it.


Why do we set $x^0 = ct$ instead of $x^0 = t$?

When we deal with Special Relativity and we start considering spacetime instead of space and time each at once, we usually see books saying that we consider a space with four coordinate $x^\alpha$ with $x^0 = ct$. We also consider this manifold to be $\mathbb{R}^4$ and give to it the metric tensor $g = \operatorname{diag}(-1,1,1,1)$. Now, why $x^0 = ct$ and not just $x^0 = t$? One possible answer might be "so that all coordinates are measured with the same units", but isn't there any deeper meaning?


Variations: Propagate custom lists programmatically

I want to propagate my custom list programmatically.We can do it with GUI easily but I want to do it programmatically.  Found the option to make it under Variations (screenshot below)


How to mount my Linux partition in Windows 8?

I am not being able to access the partition which is used by Ubuntu. In fact I don't know how to mount that partition from Windows 8. Hope folks may help me.


How do I detect when a player kills a mob in Minecraft using commands?

I'm making a Minecraft challenge video, and I want to make a data pack that has a function that executes a command when a player kills a mob. How could I do this?


I have a text in a paragraph which breaks automatically due to a max p size. Is it possible to somehow extract those line-breaks afterwards from the dom?  For example I have a text like: This is an example text that is too long for a line and breaks Which breaks after is in the dom.  I'd like to generate an array like that: ['This is an example text that is', 'too long for a line and breaks']. And if possible i'd like to also get the dash if a word breaks into syllables.  Thanks!


How to solve 'Oracle JDK 8 is NOT installed.' error, even though I have installed it before?

I have Java on my Ubuntu 16.04 system, but every time I try to install a program / package I get an error:  Do you want to continue? [Y/n] y Setting up oracle-java8-installer (8u131-1~webupd8~2) ... Using wget settings from /var/cache/oracle-jdk8-installer/wgetrc Downloading Oracle Java 8... --2017-08-14 19:20:07--  http://download.oracle.com/otn-pub/java/jdk/8u131-b11/d54c1d3a095b4ff2b6607d096fa80163/jdk-8u131-linux-x64.tar.gz Resolving download.oracle.com (download.oracle.com)... 188.43.76.48, 188.43.76.74 Connecting to download.oracle.com (download.oracle.com)|188.43.76.48|:80... connected. HTTP request sent, awaiting response... 403 Forbidden 2017-08-14 19:20:08 ERROR 403: Forbidden.  download failed Oracle JDK 8 is NOT installed. dpkg: error processing package oracle-java8-installer (--configure):  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  oracle-java8-installer E: Sub-process /usr/bin/dpkg returned an error code (1)   How can I fix this?


Ring as a finite dimensional Vector space over a field K

If R is a commutative ring containing a field K as subring and assume that R is finite dimensional vector space over K then show that every prime ideal of R will be a maximal ideal.  My approach was to show  for any prime ideal I, R/I will be a finite integral domain and hence a field which will result in I being maximal. But, here it is not given that K is finite field. Since I have just started studying this course and don't know much about Artinian or Noetherian ring so can anyone please solve this problem for infinite field using very basic ideas of ring & vector space theory and not going into domain of Artinian or Noetherian ring.


Autologin on StackExchange sites didn't work

After the read-only period yesterday the autologin fails to login on StackExchange network sites.  OS: Windows 8.1  Browser: Google Chrome 37.0.2062.76 (x64)


“possible duplicate” comment should be re-added if it's been deleted

Background: when I saw , it had 2 votes to close as duplicate, but it didn't have the usual automatically-generated comment. What happened was that  and deleted the automatic comment.  In this situation, when a second closer comes along and also decides to close as duplicate, a new comment should be generated. Otherwise the potential duplicate isn't visible until the question is closed, which often means wasted time as people redo the work of answering the question.


Should a check box field be disabled or removed from an interface if is it not going to be used?

I have a web page set up wizard that guides a user through several steps to create an object.  One of the steps in the wizard requires the users to pick via check boxes a property to their object. They can bypass this stage if they choose not to select any. We are introducing a new object type that does not support one of the check box options; however it may in the future.  I would like to re-purpose the same set-up wizard so the UI and flow are similar, if not exact. However, I am unsure if I should disable the check box option that is unavailable or if I should hide it all together...   It would seem odd to me that this set up wizard is missing information compared to the previous set up wizard. However, there is no way to select this option anyway because it isn't supported. Would it be more confusing to the user when it's missing? Or more frustrating that it's shown but I cannot choose it? Thoughts?


I wrote an authenticator to see if an email ends with "@gmail.com". I don't really know why is this returns false. Could someone help me out why is it?   public static void main(String [] args){     System.out.println(StringUtils.isValidGmail("a@gmail.com"));  // true }   public static boolean isValidGmail(String email){     if (email == null){         return false;     }     int x = email.length() - 1;     String gmail = email.substring(x-9, x+1);  // @gmail.com     return gmail == "@gmail.com"; }


"show N more comments" cannot be clicked on mobile browser (when not logged in)

Perhaps related to , this question is different in that I can click the comment link on my desktop when not logged in, but not on my iPhone. (iOS 6.1.3, built-in Safari browser).   As can be seen here, the text "show 9 more comments" is in the link colour, signifying that this can be clicked just as the name of the user who posted the last question is - but while his name can be 'clicked' leading to his profile as expected, the text "show 9 more comments" is not active:     is the question I've used as an example.  I can see this both on an iPhone and on a Windows phone, but not on an iPad.  I haven't tried to reproduce while being logged in on either of the phones.


What is the significance of the trailing dollar sign `$` on identifiers in SQL Server?

Dumping some internal views, such as sys.system_objects as done in this question I see that some identifiers end with a dollar-sign $  CREATE VIEW sys.system_objects AS     -- cutout     FROM sys.sysschobjs$ o -- XXX: HERE     LEFT JOIN sys.syspalnames n     -- not relevant   And, this works too  SELECT * FROM sys.sysschobjs$;   Even if only by convention, what is the rule here regarding this? Should I be using this in my own code?  Searching I see a lot of stuff about Excel (which is unrelated), and Money literals (which is also unrelated).   which I thought was unrelated, but I believe this terminal $ will shed a lot more light on it. Feel free to check that question for an example of some confusion


Partition Type: FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF Macbook Pro

I was trying to install Kali linux in a dual boot fashion when I accidentally ended up install a terminal only version of Debian as a second partition. So I decided to retry, which meant I needed to delete the Debian partition. When I tried to in Disk Utility, it gave me errors, so I booted into internet recovery mode and removed the partitions there. I then proceeded in clicking the Apple Logo and selecting the choose boot partition thing. It showed nothing. At first I panicked, thinking I had somehow deleted all of my data. I tried creating a second partition, so I could install Mac OS there and then fix my mac from there. I clicked on the create partition, waited 3ish hours while I went out, came back and it said preparing to partition. So I rebooted and saw that the partition type was: FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFF. So I installed Mac OS X onto a painfully slow flash drive (15-20MB/s) and then looked up my problem. I found other solution people had created only they were specific to the exact case. I do not know what the partition type is supposed to be so here is my info: /dev/disk1 is the USB flash drive that is running MAC OS X so I can use my laptop.  sh-3.2# diskutil list /dev/disk0    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:      GUID_partition_scheme                        *500.3 GB   disk0    1:                        EFI NO NAME                 209.7 MB   disk0s1    2: FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF               450.1 GB   disk0s2 /dev/disk1    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:      GUID_partition_scheme                        *31.4 GB    disk1    1:                        EFI EFI                     209.7 MB   disk1s1    2:                  Apple_HFS Fixer OS                30.5 GB    disk1s2    3:                 Apple_Boot Recovery HD             650.0 MB   disk1s3   And here is some more:  sh-3.2# gpt -r show /dev/disk0     start       size  index  contents         0          1         PMBR         1          1         Pri GPT header         2         32         Pri GPT table        34          6                 40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B    409640  879039128      2  GPT part - FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF 879448768   97656259          977105027         32         Sec GPT table 977105059          1         Sec GPT header   How can I mount this partition again? Which command should I use?


How do you add a user in ubuntu using the terminal


errors upgrading from 14.04 to 16.04 about Unknown Multi-Arch type for compiz, libkf5akonadisearch-bin packages

I'm trying to upgrade my 14.04 machine to 16.04 using do-release-upgrade. After downloading the package lists for wily, I see the following errors:  Unknown Multi-Arch type 'no' for package 'compiz-core' Unknown Multi-Arch type 'no' for package 'compiz-gnome' Ignoring Provides line with DepCompareOp for package python-cffi-backend-api-max Ignoring Provides line with DepCompareOp for package python-cffi-backend-api-min Ignoring Provides line with DepCompareOp for package python3-cffi-backend-api-max Ignoring Provides line with DepCompareOp for package python3-cffi-backend-api-min Unknown Multi-Arch type 'no' for package 'libkf5akonadisearch-bin' Ignoring Provides line with DepCompareOp for package php-psr-http-message-implementation Ignoring Provides line with DepCompareOp for package php-psr-log-implementation Ignoring Provides line with DepCompareOp for package php-math-biginteger Unknown Multi-Arch type 'no' for package 'compiz-core' Unknown Multi-Arch type 'no' for package 'compiz-gnome' Ignoring Provides line with DepCompareOp for package python-cffi-backend-api-max Ignoring Provides line with DepCompareOp for package python-cffi-backend-api-min Ignoring Provides line with DepCompareOp for package python3-cffi-backend-api-max Ignoring Provides line with DepCompareOp for package python3-cffi-backend-api-min Unknown Multi-Arch type 'no' for package 'libkf5akonadisearch-bin' Unknown Multi-Arch type 'no' for package 'compiz-core' Unknown Multi-Arch type 'no' for package 'compiz-gnome' Unknown Multi-Arch type 'no' for package 'compiz-core' Unknown Multi-Arch type 'no' for package 'compiz-gnome' You may want to run apt-get update to correct these problems   It then proceeds to abort the installation. The suggested run of apt-get update doesn't seem to do anything. Googling for the above error messages yielded others having similar problems when upgrading to other, previous releases, although I've not come across any apparent fixes. It's suggested that an apt upgrade could fix the problem, but I don't see a way to easily do that (it's up to date with the latest trusty package).  What should I do in order to upgrade directly to 16.04?


If $a$ and $b$ are relatively prime, prove that $a + 2b$ and $2a+b$ are also relatively prime or have a gcd of $3$.

If $a$ and $b$ are relatively prime, prove that $a + 2b$ and $2a+b$ are also relatively prime or have a $\gcd$ of $3$.  I'm very new to number theory so please don't assume I am familiar with some of the terminology.


Why does this MWE not use correct UK English hyphenation? The second line has an influence on alternate, but not on nevertheless:  \documentclass{article} \usepackage[UKenglish]{babel} \begin{document}     \fbox{\parbox{8mm}{\hskip0pt alternate}}      \fbox{\parbox{8mm}{\hskip0pt nevertheless}}      \end{document}     Correct hyphenations are:  BE: never|the|less ()  AE: nev·er·the·less (, )  (Bonus question: Why is the first word in my MWE not hyphenated? .)  Some part of my log output:  This is pdfTeX, Version 3.14159265-2.6-1.40.17 (MiKTeX 2.9 64-bit) (preloaded format=pdflatex 2016.6.30)  19 JUL 2016 13:13 entering extended mode **./hindex.tex (hindex.tex LaTeX2e <2016/03/31> patch level 1 Babel <3.9r> and hyphenation patterns for 4 language(s) loaded.   This output is exactly the same, regardless of whether I use english or UKenglish.


To detect whether my phone is jailbroken or not?

How would I know whether my iPhone is jailbroken?  If it is jailbroken, would you recommend that I update to a newer version?


In physics, I have come across some definitions of physical quantities (one such definition is that of the physical quantity Force, $\vec{F} \equiv m\vec{a} $) that do not tell us what physical quantities are.   I guess the following statement:     Experiments tell us that these definitions are reasonably accurate, and that they help us construct reasonable mathematical models   (Corrections are welcome)   My question is, do all definitions in physics avoid the questions, "What is Force?", "What is momentum?", etc.?


Prove that if the sum of digits of a number is divisible by 3, so is the number itself.

Here is the proof of the converse:  Iff a number $n$ is divisible by $3$, then the sum of its digits is also divisible by $3$.  Proof:  We know $n \mod 3 = 0$. By the basis representation theorem, $n$ can be re-written as $n_k10^k + n_{k-1}10^{k-1} + \cdots + 10n_1 + n_0 \equiv 0 \mod 3$. By the modular arithmetic addition rule, we can take $n_k10^k \mod 3 + n_{k-1}10^{k-1} \mod 3 + \cdots + 10n_1 \mod 3 + n_0 \mod 3$. But then we just get $n_k + n_{k-1} + \cdots + n_1 + n_0$, since $10 \mod 3 \equiv 1$.   Now suppose that the sum of the digits was divisible by 3. How can I prove that the representation in base $10$ is divisible by $3$?


Unexpected values, after passing by object reference in Java

I would appreciate some help with the following, asked previously, not addressed in older questions related to Java and references.  Java is pass by object reference, years ago we called references, pointers. I am assuming this in predicting the output, however, even when I make tortVals and vraiVals aliases of each other, and expect for v1[1] and v2[1] to be the same, they are not. v2[1] still has a value of 6. I have not seen this addressed in existing issues, and still am asking for help. Same thing happens with the array of strings - the array arguments are pointers, yet the changes expected do not follow. Specifically, v2[1] remains 6, v3[1] is set to 'huit', instead of what I would expect, 'trois'. Thanks, Jacques  Here is my prior question: I have a small sample piece of code below - I predicted the output (print) would be 5 5 trois, because of the references. I got it wrong, it's 5 6 huit. Given that references allow for the area 'pointed to' to be changed, what am I missing? Help much appreciated, obviously this is a test case for a bigger scenario.   public static void main(String[] args) {         essayer();     }      public static void resetVals(int[] vraiVals, int[] tortVals, String[] noms) {       vraiVals[1] = 5;       tortVals = vraiVals;       noms[1] = new String("huit");       noms = new String[3];       noms[1] = new String("trois");     }      public static void essayer() {         int[] v1 = {1,2,3};         int[] v2 = {5,6,7};         String[] v3 = {"un", "deux", "trois"};         resetVals(v1, v2, v3);         System.out.println(v1[1] + " " + v2[1] + " " + v3[1]);     }


video material displays incorrect frames

I'm following a lightsaber tutorial. A video is loaded as an image texture material to a plane that then is set to always face the user/camera. A plane with a emission material is created and then I go frame by frame to line it up or use motion tracking with a stick I'm holding in the video.(I'm trying both just for fun.) The problem is that the video frames are changing position with around 1 or 2 frames ahead or after at random.(So I can't just change the video offset.) When loading the video into a movie clip editor the video lines up correctly. The video cant be loaded as a background video because this removes the emmision from the saber. I'm rendering in EEVEE. The video is set to auto update the video frame when a new frame is selected.I set the frame count high for the video (around 6000, later 2000 but did no difference). Tell me if you need any more information.


I had been eating before I visited you. I had eaten before I visited you.  How do you know when to use either of them?


Prove that for any integers $m$ and $n$ we have to: $mn=(m,\,n)[m,\,n]$.

Prove that for any integers $m$ and $n$ we have to: $mn=(m,\,n)[m,\,n]$ ($(m,\,n)$  being the gcd & $[m,\,n]$ the lcm). How can i prove it?


I am trying to connect with Microsoft SQL Server Database called SimpleBase, which is on my computer with this code:      static final String JDBCDriver = "com.mysql.jdbc.Driver";     static final String dbURL = "jdbc:mysql://localhost/SimpleBase";     public static void main(String[] args) throws ClassNotFoundException, SQLException {              Connection conn = null;             Statement stmt = null;              try{                     Class.forName(JDBCDriver);                     System.out.println("Connecting");                     conn = DriverManager.getConnection(dbURL);                     conn.close();             }             catch(SQLException se){                     se.printStackTrace();             }             catch(Exception e){                     e.printStackTrace();             }     }   and the output in Eclipse is something like this:  Connecting  com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure  The last packet sent successfully to the server was 0 milliseconds ago. The  driver has not received any packets from the server.      at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)     at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)     at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)     at java.lang.reflect.Constructor.newInstance(Unknown Source)     at com.mysql.jdbc.Util.handleNewInstance(Util.java:389)     at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1038)     at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:338)     at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2237)     at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2270)     at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2069)     at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)     at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)     at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)     at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)     at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)     at java.lang.reflect.Constructor.newInstance(Unknown Source)     at com.mysql.jdbc.Util.handleNewInstance(Util.java:389)     at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)     at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)     at java.sql.DriverManager.getConnection(Unknown Source)     at java.sql.DriverManager.getConnection(Unknown Source)     at PROKOM.Zadanie11.test.main(test.java:23) Caused by: java.net.ConnectException: Connection refused: connect     at java.net.DualStackPlainSocketImpl.connect0(Native Method)     at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)     at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)     at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)     at java.net.AbstractPlainSocketImpl.connect(Unknown Source)     at java.net.PlainSocketImpl.connect(Unknown Source)     at java.net.SocksSocketImpl.connect(Unknown Source)     at java.net.Socket.connect(Unknown Source)     at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:213)     at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:297) ... 15 more   I suspect that I did something wrong. Can someone tell me what? If it's not exactly my fault, can someone tell what's wrong?


Is there a way to show a 404 page if the current logged in user does not have the right clearance to view the page? I am looking for a PHP method, something like  if( !current_user_can('administrator') ) { show_404(); exit(); }   I have thought about using a redirect, but I would like to keep the url the same.


My return flight from Phuket gives me an 8 hour layover at 10:50 pm in Narita Aiport.  Any recommendations for nearby activities?


As I was testing this form data entry I had no issues.  When I tried adding more complex text, in the textarea that is picked up by the $post_content = $_POST['post_content'];  with numeric and non-alphabetic characters I'm met with this error.       QUERY FAILED: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near   My code is as follows:  <?php      if (isset($_POST['create_post'])){          $post_title = $_POST['title'];         $post_author = $_POST['author'];         $post_category_id = $_POST['post_category_id'];         $post_status = $_POST['post_status'];         $post_image = $_FILES['image']['name'];         $post_image_temp = $_FILES['image']['tmp_name'];         $post_tag = $_POST['post_tag'];         $post_content = $_POST['post_content'];         $post_date = date('d-m-y');         $post_comment_count = 4;          move_uploaded_file($post_image_temp, "../images/$post_image");          $query = "INSERT INTO posts (post_category_id, post_title, post_author, post_date, post_image, post_content, post_tag, post_comment_count, post_status) ";          $query .= "VALUES ({$post_category_id},'{$post_title}','{$post_author}',now(),'{$post_image}','{$post_content}','{$post_tag}','{$post_comment_count}','{$post_status}' ) ";          $create_post_query = mysqli_query($connection, $query);         checkQuery($create_post_query);     } ?> <form action="" method="post" enctype="multipart/form-data">
         Post Title         <input type="text" class="form-control" name="title">

         Post Category Id         <input type="text" class="form-control" name="post_category_id" placeholder="Please enter a number">

         Post Author         <input type="text" class="form-control" name="author">

         Post Status         <input type="text" class="form-control" name="post_status">

         Post Image         <input type="file" name="image">

         Post Tags         <input type="text" class="form-control" name="post_tag">

         Post Content         <textarea class="form-control" name="post_content" id="" cols="30" rows="10"></textarea>

         <input class="btn btn-primary" type="submit" name="create_post" value="Publish Post">
 </form>   I attempted using mysqli_real_escape_string in combination with my $post_content = $_POST['post_content']; and had no success, which leads me to think my query syntax is off.  Any help will be greatly appreciated.


Given $S \in B(Y^{*}, X^{*})$, does there exist $T\in B(X,Y)$ such that $S=T^{*}$?

Let $X, Y$ be Banach spaces, $S \in B(Y^{*}, X^{*})$. Does such operator $T \in B(X, Y)$ exist so that $T^{*}=S$?  I suppose that the answer should be - no. Are there any hints that might help in constructing a counterexample?  Any help would be much appreciated.


Is it grammatical to split a qualifying subclause from the qualified noun?

While drafting an answer on another site, at one point I came up with the following sentence:  *You can’t force someone to follow a contract who hasn’t agreed to it.  I think the intended meaning is clear. But if you apply the grammar rules strictly, without regard for semantics, it would seem that the ‘who’ applies to the contract, which is a strange thing to say. Is this construction grammatical and does it have a distinct name?


Let $A, B$ and $C$ be the angles of an acute triangle. Show that: $\sin A+\sin B +\sin C > 2$. I started from considering $$\begin{align}\sin A+\sin B+\sin (180^o-A-B) &= \sin A+\sin B+\sin(A+B)  \\&=\sin A+\sin B+\sin A\cos B + \cos A\sin B  \\&=\sin A(1+\cos B)+\sin B(1+\cos A).\end{align}$$ How to proceed?


Where does magic actually lie: In wizards or wands?

I always thought about this whenever I saw Harry Potter movies or read books, that where exactly magic lies? Is it in wizards or wands? As mentioned in , Harry is able to make the glass disappear. Then in  he blows away his aunt without even touching the wand. So if magic is possible without wands why do they need it in the first place? Also, Ollivander tells Harry that wand chooses the wizards, so does wand actually have magic? Kindly help.


First, I am new to Ubuntu and have never used any Linux operating system before.  I have removed Windows from all of my PCs and am trying something different.  The first question I have is really about installing games.  I already have steam (very user friendly) so I have no problems there.  I want to play Urban Terror which I downloaded from their site, but I don't know how to install the package from there.  I found a way through terminal, which was going okay, downloading at 2.8Mb/s to start now it dropped 2,888PB/s, which is going to take forever.  Attached are some pictures, so you can see what I have, what I am doing, and the problems I am having.


How to resolve Google "Indexed, though blocked by robots.txt"

Recently Google has been complaining about certain pages saying:  Indexed, though blocked by robots.txt   I am confounded by this error.  Yes the page, is blocked by robots.txt and it has always been.  Nothing new has happened and I don't want it crawled or indexed.  Why is google indexing the page when I explicitly telling it not to?  I realize I can add a meta tag like <meta name="robots" content="noindex"> but why should this be necessary?


How SVD is used for dimensionality reduction?

Given a $M \times N$ data matrix $ D = (x_1, x_2, \cdots, x_M)^{T}$.   Applying singular value decomposition to $D$ yields  $$D = USV^{T} = (u_1, u_2, \cdots, u_M) \begin{pmatrix}     s_1 &&0\\     &\ddots\\     0& & s_N \\     \hline     &0     \end{pmatrix}_{M\times N} (v_1, v_2, \cdots, v_N)^{T} $$  Choose $d$ singular values, we have   $$D' = (u_1, u_2, \cdots, u_M) \begin{pmatrix} s_1 & &\\ & \ddots &\\ & & s_d\\ \hline & 0 \end{pmatrix}_{M \times d} = (f_1, f_2, \cdots, f_M)^{T}$$ in which $D'$ is an $M \times d$ matrix.   My question is:  What is the relation between $D'$ and $D$? To be specific, can $f_i$ be interpreted as a reduced version of $x_i$? If so, then where is the effect of the orthogonal matrix $V$?  For me, SVD can be used for tuning the "resolution" of a matrix in another way.  Given $D = USV^{T} = \sum_iu_is_iv_i^{T}$, thus the more singular values we take into account, the better the matrix will be reconstructed.


What does the *.*;auth,authpriv.none -/var/log/syslog line mean in rsyslog config file?

I'm trying to understand the /etc/rsyslog.conf file, but I'm missing something. For example, this is a part of the file:  auth,authpriv.*         /var/log/auth.log *.*;auth,authpriv.none      -/var/log/syslog cron.*              /var/log/cron.log daemon.*            -/var/log/daemon.log kern.*              -/var/log/kern.log lpr.*               -/var/log/lpr.log mail.*              -/var/log/mail.log user.*              -/var/log/user.log   According to  page:     The facility is one of the following keywords: auth, authpriv, cron,   daemon, kern, lpr, mail, mark, news, security (same as auth), syslog,   user, uucp and local0 through local7.      The priority is one of the following keywords, in ascending order:   debug,info, notice, warning, warn (same as warning), err, error (same   as err) crit, alert, emerg, panic (same as emerg). The keywords error,   warn and panic are deprecated and should not be used anymore. The   priority defines the severity of the message.      An asterisk ("*") stands for all facilities or all priorities,   depending on where it is used (before or after the period). The   keyword none stands for no priority of the given facility.      You can specify multiple facilities with the same priority pattern in   one statement using the comma (",") operator. You may specify as much   facilities as you want. Remember that only the facility part from such   a statement is taken, a priority part would be skipped.      Multiple selectors may be specified for a single action using the   semicolon (";") separator. Remember that each selector in the   selector field is capable to overwrite the preceding ones. Using this   behavior you can exclude some priorities from the pattern.   So, this is pretty understandable but what about the file path on the right. It can be just a path, or path with | or - before it (or maybe even something else). What is the difference between the three?


Do I have to calculate it all out? That would be a pretty long calculation and boring... Is there an easier ways to find the real part? Thanks in advance


has posted a question which has been closed as off-topic. However, they earned 6 reputation from it (thanks to someone who upvoted it). Despite this, they have 1 reputation being shown in their profile (and no they haven't been suspended).  I figured this out after I saw their reputation graph.  How is this possible? Note: Since now the question has been deleted, everything is back to normal. Also, I am not saying that the user should have had those reputation; I just want to understand the system.


I am receiving an error while deploying LWC component from VS Code as below.  Error: Value too long for field: Source maximum length is:131072 force-app\main\default\lwc\app360BaseLinesLWC\app360BaseLinesLWC.js No base file for markup://c:app360BaseLinesLWC  My JS file size is 129KB, Is there any limit of LWC file sizes?


How do I add the below string to a dictionary in key value pair format

Input : "name=xyz,city=bangalore,company=abc,education=BE"  Output : {"name":"xyz", "city":"bangalore", "company":"abc", "education":"B.E"}  I am able to get ['name=xyz', 'city=bangalore', 'company=abc', 'education=BE'] but am stuck on splitting the word inside the list and appending to dictionaries.


Did Hagrid Disapparate in The Philosopher's Stone?

In The Philosopher's Stone,      Hagrid helped Harry on to the train that would take him back to the   Dursleys, then handed him an envelope.   "Yer ticket fer Hogwarts, " he said. "First o' September -- King's Cross   -- it's all on yer ticket. Any problems with the Dursleys, send me a   letter with yer owl, she'll know where to find me.... See yeh soon,   Harry."      The train pulled out of the station. Harry wanted to watch Hagrid until   he was out of sight; he rose in his seat and pressed his nose against   the window, but he blinked and Hagrid had gone.   Having a wand is necessary to apparate, and, as we later see that Hagrid keeps the fragments of his broken wand in his umbrella, and Hagrid has his umbrella with him throughout this chapter, did Hagrid Disapparate?


$\{y(n)\} \in l_1$ if $\sum_{n = 1}^{\infty} x(n) y(n)$ converges for all $x(n) \in c_0$

Let $\{y(n)\}$ a sequence of reals (or complex) numbers such that $\sum_{n = 1}^{\infty} x(n) y(n)$ converges for all $\{x(n)\} \in c_0$ (it means $\lim_{n \to \infty} x(n) = 0$). Then I have to show that $\{y(n)\} \in l_1$, it means $\sum_{n = 1}^{\infty} |y(n)| < \infty$. Should I have to replace $x(n)$ by a concrete sequence to show it? Thanks


How do I translate these weird UTF-8 "from" strings in e-mail context?

Receiving e-mails, I end up with "complete from strings" such as this one:  $test = '=?UTF-8?Q?Test=C3=B6p?= <no-reply@Testöp.tld>';   How do I get rid of the "=?UTF-8?" nonsense? Obviously I don't mean to just string-replace it, but to convert it properly to an actual UTF-8 string. It's supposed to be something like:  $test = 'Testöp <no-reply@Testöp.tld>';   I don't know why I get this in the first place, but I bet there is a simple function to do it somewhere in PHP.  Note: It's not utf8_decode()! That one does nothing to that string!


Hide Object or Collection using Keyframe

I have seen tutorials on the older Blender version to hide and unhide an object using keyframes.  I haven't been successful in 2.8.  I thought you could use collections to control this, but no luck.  I basically want to control the visibility of an object and various parts of the timeline.  What's the trick in 2.83.  Thanks


How to iterate Arrival and Departure date in Java, Mysql

I have combobox for the type of room and 2 text boxes for the Arrival and Departure,  What I want is when the Arrival = 2017-09-01 - Departure = 2017-09-05 is already exist, The customer will not able to choose 2017-09-02 to 2017-09-05 in the same type of room  String sql = "SELECT * FROM reservation WHERE room=? and arrival=? and  departure=?";  try{         pst=conn.prepareStatement(sql);         pst.setString(1, ComboBox.getSelectedItem().toString());         pst.setString(2, txtArrival.getText());         pst.setString(3, txtDeparture.getText());         rs=pst.executeQuery(); if(rs.next()){ // the customer needs to choose other date or room } else{ // continue to fill up the form below } }


I hope you doing good. Linux Directories contain some system files usually it's hard to detect if Linux doesn't have color-coding enabled or no extension/suffix with the file. We use ls -l, ls -lah command to see the file type and other properties. Output can be as shown below  ls -rwxrwxrwx          Its a file (-) drwxrwxrwx          Its a directory (d) lrwxrwxrwx          What dose (l) stands for? I wanted to know all kind of files we can have inside Linux (on basis of -, d, l if more) and the list of characters we use to identify them. Example - stands for files d stands for directory l stands for what???