How to divide LaTeX table cells vertically?

I want my table to have separated cells. Basically double lines but I can't figure how to have horizontal lines disconnected. I tried \hline and \cline but those connect too.  This is best I can do:    This is how I want my table to look:   \begin{tabular}{|c||c||c||c|}   \hline   \multicolumn{2}{|c||}{First Cell}&   Second Cell&   Third Cell\\   \hline   \hline   \begin{tabular}{@{}l@{}} Data\\ Data\\ Data\\   \end{tabular}&   \begin{tabular}{@{}l@{}}     Data\\     Data\\     Data\\   \end{tabular}&   \begin{tabular}{@{}l@{}}     Data\\     Data\\     Data\\   \end{tabular}&   \begin{tabular}{@{}l@{}}     Data\\     Data\\     Data\\   \end{tabular}\\    \hline  \end{tabular}


Minecraft has not been letting me log in since yesterday. I have no idea why. When I logged off of a server I was gonna get back on but I closed minecraft. When I went back on it wanted me to log in. I had no idea why so I put my account in and it said "could not log in as -Minecraft name-, please try again" I had no idea why. Today it still isn't working. I tried getting on MineChat too and that didn't work. Please help.  Btw this is what its doing when I try to change it


How to find all solutions of $\cos(z) = 0$, where $z\in\mathbb{C}$?

I am stuck on finding all solutions of the equation $\cos(z) = 0$, where $z\in\mathbb{C}$.  I found this proof, however, I cannot figure out the logic behind the last few steps. \begin{align} \cos(z) &= \dfrac{e^{iz}+e^{-iz}}{z} \\\\ &= 0 \\\\ e^{iz}+e^{-iz} &= 0 \\\\ e^{i(x+iy)} &= -e^{-i(x+iy)} \\\\ e^{ix}e^{-y} &= -e^{ix}e^y \\\\ e^{ix}e^{-y} &= e^{i\pi}e^{-ix}e^y \\\\ e^{-y}e^{ix} &= e^ye^{i(\pi-x)} \\\\ |e^{-y}e^{ix}| &= |e^ye^{i(\pi-x)}| \end{align}  This is where I get a bit confused. It follows from the modulus that, [ e^{-y} = e^y ] but why? Are we just shaving off the imaginary component? Or is it because $e^{-y}$ is real so it acts as the radius in $re^{i\theta}$?  So we have \begin{align} -y &= y \\\\ y &= 0 \\\\ e^{ix} &= e^{i(\pi-x)} \end{align}  Therefore we have from this that, $x - (\pi - x)= 2\pi k, \forall k\in\mathbb{Z}$... but why is that? Where is the $2\pi k$ coming from? I understand it has to do with the unit circle... is $i = 2\pi k$?  From that result we have \begin{align} 2x &= \pi + 2\pi k \\\\ x &= \dfrac{\pi}{2} + \pi k \\\\ z &= \dfrac{\pi}{2} + \pi k, \forall k\in\mathbb{Z} \end{align}  When I tried this problem on my own I did, \begin{align} \cos(z) &= \dfrac{e^{iz}+e^{-iz}}{2} \\\\ &= 0 \\\\ e^{iz} + e^{-iz} &= 0 \\\\ e^{iz} &= -e^{-iz} \\\\ e^{iz} &= e^{i\pi}e^{-iz} \\\\ e^{iz} &= e^{i(\pi-z)} \\\\ z &= \pi - z \\\\ 2z &= \pi \\\\ z &= \dfrac{\pi}{2} \end{align}  But this does not result in the infinite solutions it should result in.


Here's what my current partition table looks like:   Now, I'd like to increase the size of my Ubuntu partition (/dev/sda8) to, say, 20 GB. But it seems to me there's no way to do that other than deleting everything and starting anew, which makes me scared (don't want to lose all the settings and good stuff).  When I tried to do this via the GParted editor in boot mode, it warned that moving partitions will mess up the bootloader and operating systems and what not, so I didn't do it.  I'm a total noob, so am requesting someone to help me achieve this. Thanks!


Why does QGIS spontaneously corrupt shapefile data?

I'm using QGIS 2.14 (Mac), but I have had the same problem with 2.8 (Ubuntu). When I am editing a shapefile, QGIS seems to spontaneously corrupt the data in unpredictable and catastrophic ways that include:   Duplication of features Deletion of features Scrambling of attribute data   Most recently, this occurred while using the Table Manager plugin to rename a column of the attribute table. Upon saving the change, one of the columns of the attribute table (not the one being renamed) was suddenly scrambled such that features were unpredictably reclassified, completely corrupting the file and forcing me to reload a backup version.    The problem seems to be associated with saving, though I usually don't discover the corruption until some time after it occurred, so I can't say for sure what the circumstances were in most cases, the exception being the case described above.   I realize this might be the same problem described here    If so, it is evidently still a problem in 2.14, and there was never a satisfactory answer provided. If not, does anyone have a clue as to what is going on? This makes QGIS completely unusable.   -------------- EDIT ---------------  I was able to replicate the result by reloading a backup version and repeating the renaming and saving that precipitated the corruption the first time. The problem seems to be specifically with the Table Manager plugin, similar to what was reported here:   Apparently it remains unresolved, so I guess one should stay away from Table Manager for the time being.


$$\text{Please read the whole question before answering}$$  Before I ask my question, I would like to say that "Yes, I do know a photon has no mass."  I was helping someone here on P.SE with the subject of how photons are produced. For some reason I was also thinking of Einstein at the time I helped said person, and as it often does for me, and I started thinking about $E=MC^2$ and the energy of a photon.  I looked it up later (, , and ) and the respective energies of the wavelengths Blue(0.445 microns), Green(0.525 microns), and Red(0.644 microns) are $4.46*10^{-19} J$, $3.78*10^{-19} J$, and $3.08*10^{-19} J$.  Now I don't know calculus or higher level physics, but it occurred to me that if something has energy, by Einstein's $E=MC^2$, it must have mass (Because the speed of light is constant). I did a quick thought experiment, and sure enough, something with no mass would have no energy $$E=MC^2$$ $$E=0⋅C^2$$ $$E = 0$$  Using SI units, since the units used are arbitrary, I did another thought experiment:  Using $E=MC^2$, what is the mass of a photon at the wavelength 0.445μm (Blue)? $$E=MC^2$$ $$4.46⋅10^{-19} \text{J} = M⋅C^2$$ $$4.46⋅10^{-19} \text{J} = M⋅(299,792,458 \text{ m/s})^2$$ $$4.46⋅10^{-19} \text{J} = M⋅(8.98755⋅10^{16} \text{ m}^2/\text{s}^2)$$ $$\text{And since we can rearrange to get } E/C^2 = M,$$ $$\frac{4.46⋅10^{-19} \text{J}}{8.98755⋅10^{16} \text{ m}^2/\text{s}^2} = M$$ $$\frac{4.46⋅10^{-19} \text{Kg⋅m}^2/\text{s}^2}{8.98755⋅10^{16} \text{ m}^2/\text{s}^2} = M$$ $$\frac{4.46⋅10^{-19} \text{Kg}}{8.98755⋅10^{16}} = M$$ $$4.96242⋅10^{-36} \text{Kg} = M$$  I don't know about you, but that does not look like a mass of 0.  Lets do another: What is the mass of a photon at frequency 0.525μm (Green)? $$E=MC^2$$ $$3.78⋅10^{-19} \text{J} = M⋅C^2$$ $$3.78⋅10^{-19} \text{J} = M⋅(299,792,458 \text{ m/s})^2$$ $$3.78⋅10^{-19} \text{J} = M⋅(8.98755⋅10^{16} \text{ m}^2/\text{s}^2)$$ $$\frac{3.78⋅10^{-19} \text{J}}{8.98755⋅10^{16} \text{ m}^2/\text{s}^2} = M$$ $$\frac{3.78⋅10^{-19} \text{Kg⋅m}^2/\text{s}^2}{8.98755⋅10^{16} \text{ m}^2/\text{s}^2} = M$$ $$\frac{3.78⋅10^{-19} \text{Kg}}{8.98755⋅10^{16}} = M$$ $$4.20581⋅10^{-36} \text{Kg} = M$$  Again, something doesn't smell right.  Honestly, I'm not sure what to make of this. Obviously, if photons had any mass at all, Earth would probably not be here (What with the sun sending hundreds of trillions of photons a year, for 4.5 billion years. We'd have been sandblasted away long ago)  So clearly something is very wrong. In order of most, to least likely:   I messed up with something in my calculations. I assumed something, that shouldn't have been assumed. I made some, other, unknown mistake somewhere. Photons have special rules, when it comes to this equation. The equation I used is an oversimplification. There's something in calculus/higher level physics that explains this, and I am just oblivious to it. There is a debate going on over this somewhere. Its a conspiracy. Whales can fly. Einstein was wrong.   I got my information/double checked my information at these websites:    The speed of light ()()  Energy of photon ()()()    Someone please shed light on this, it's been driving me crazy since 8/26/14.  TIA P.SE


Bones are deforming the mesh at different rates. Is there a way to fix this?

When trying to control the eyelid and eyelashes mesh (both are part of the same mesh although the eyelashes are not attached to the rest of the head). Moving the gaze bone up causes the eyelids to move at the appropriate speed, but the eyelashes move at a different speed and don't stay where they need to be.  Eyelid deform bones are circled in red. These bones are restricted to X rotation only.     After changing the gaze bone to make the character look up, eye lashes detach.   I have tried weight painting the eyelashes but it doesn't make a difference unless the weight is set to zero and then the eyelashes don't move at all.  Is there a way to fix this?  Link to the .blend file:


how to give custom filenames when executing split command in unix?

Is there a way to give custom filenames for split command? I am splitting a file that is 100GB into chunks of 128MB. Here is what I am doing  split -b 128000k mydata.csv.  This creates files with following names xaa,xab,xac,.. etc. I am wondering if it is possible to have custom names like mydata_0.csv, mydata_1.csv for each of the splits.


How do I install Python 3.7 on Ubuntu 16.04 and 18.04?

I have several systems. Some are 16.04 mini-servers and I cannot update the OS yet. The others have been updated to Ubuntu 18.04. (The 18.04 version I used has Python 3.6.5 on it).


I've been learning how to make planet from this course: . Planets textures are used as materials over the surface of a sphere but I wanted to know. Is it possible to use moving video footage as a material on a sphere?


So the SMEs at my current place of employment want to try and disable the back button for certain pages.  We have a page where the user makes some selections and submits them to be processed.  In some instances they have to enter a comment on another page.    What the users have figured out is that they don't have to enter a comment if they submit the information and go to the page with the comment and then hit the back button to return to the previous page.    I know there are several different solutions to this (and many of them are far more elegant then disabling the back button), but this is what I'm left with.  Is it possible to prevent someone from going back to the previous page through altering the behavior of the back button.  (like a submit -> return false sorta thing).    Due to double posting information I can't have it return to the previous page and then move to the current one.  I can only have it not direct away from the current page.  I Googled it, but I only saw posts saying that it will always return to the previous page.  I was hoping that someone has some mad kung foo js skills that can make this possible.  I understand that everyone says this is a bad idea, and I agree, but sometimes you just have to do what you're told.


Installing from such repository can't be done securely

I just switched to Ubuntu 19.04 from Windows. Whenever I try to install anything from the terminal I get such error which says installing from such repository can't be done securely hence it is disabled.     mohit@mohit-desktop:~$ sudo apt update [sudo] password for mohit:  Ign:1 http://dl.google.com/linux/chrome/deb stable InRelease Ign:2 http://ppa.launchpad.net/webupd8team/atom/ubuntu disco InRelease Hit:3 http://dl.google.com/linux/chrome/deb stable Release Err:5 http://ppa.launchpad.net/webupd8team/atom/ubuntu disco Release   404  Not Found [IP: 64:ff9b::5bbd:5f53 80] Reading package lists... Done E: The repository 'http://ppa.launchpad.net/webupd8team/atom/ubuntu disco 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. mohit@mohit-desktop:~$    Someone told me to do some stuff in the software & updates and asked me to do uncheck some checkboxes and I dont remember it so can anyone tell that again to me please...


Disable auto-maximizing windows in 18.04

How to disable auto-maximizing windows in Ubuntu 18.04 without using Unity Tweak Tool.


Convert downloaded YouTube videos (downloaded with youtube-dl) to audio-only, with no loss?

If one downloads videos from YouTube using youtube-dl, they get .mp4 files which are a ISO Media, MPEG v4 system, version 2.  Can these files be converted to audio-only, ideally with no quality loss? The goal is to save space by throwing out the unneeded visual part.


ffmpeg installed but not the right version

I am using Ubuntu 14.04.4 LTS with Plesk version   12.5.30.  I have installed ffmpeg with these steps:  sudo add-apt-repository ppa:mc3man/trusty-media sudo apt-get update sudo apt-get install ffmpeg   That seems to be the common answer when I search for how to install it.  When I do a version on it, I get this:  ~$ /opt/ffmpeg/bin/ffmpeg --version ffmpeg version N-80901-gfebc862 Copyright (c) 2000-2016 the FFmpeg developers   built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3)   configuration: --extra-libs=-ldl --prefix=/opt/ffmpeg --mandir=/usr/share/man --enable-avresample --disable-debug --enable-nonfree --enable-gpl --enable-version3 --enable-libopencore-amrnb --enable-libopencore-amrwb --disable-decoder=amrnb --disable-decoder=amrwb --enable-libpulse --enable-libfreetype --enable-gnutls --enable-libx264 --enable-libx265 --enable-libfdk-aac --enable-libvorbis --enable-libmp3lame --enable-libopus --enable-libvpx --enable-libspeex --enable-libass --enable-avisynth --enable-libsoxr --enable-libxvid --enable-libvidstab   libavutil      55. 28.100 / 55. 28.100   libavcodec     57. 48.101 / 57. 48.101   libavformat    57. 41.100 / 57. 41.100   libavdevice    57.  0.102 / 57.  0.102   libavfilter     6. 47.100 /  6. 47.100   libavresample   3.  0.  0 /  3.  0.  0   libswscale      4.  1.100 /  4.  1.100   libswresample   2.  1.100 /  2.  1.100   libpostproc    54.  0.100 / 54.  0.100   I am trying to install ClipBucket Installer v2.8.1 STABLE and it keeps giving me the message:  Unable to find ffmpeg   I believe this is due to it not being the right version. Here is the check in Clipbucket:      case "ffmpeg":     {         $ffmpeg_path = exec("which ffmpeg");         $ffmpeg_version = shell_output("$ffmpeg_path -version");          $version = false;         preg_match("/SVN-r([0-9]+)/i",$ffmpeg_version,$matches);         if(@$matches[1])             $version = 'r'.$matches[1];         preg_match("/version ([0-9.]+)/i",$ffmpeg_version,$matches);         if(@$matches[1])             $version = $matches[1];          if(!$version)             $return['err'] = _("Unable to find ffmpeg");         else             $return['msg'] = sprintf(_("Found FFMPEG %s : %s"),$version,$$ffmpeg_path);     }     break;   Where do I find the latest version that ClipBucket supports?


Is there an official (or standard) order for footnotes in a single page or article?  The first footnote is usually marked with a: * (asterisk).  The second with a # (hash mark).  I've seen the third marked with a triangle but I can't seem to figure out what it's called.  Is there a list of offical footnote marks based on order?


Prove that $z^2 \equiv ab\pmod p$ is solvable if and only if both or neither of $x^2 \equiv a \pmod p$, $x^2 \equiv b \pmod p$ are solvable.

Suppose the $p$ is an odd prime not dividing $ab$.  Prove that $z^2 \equiv ab \pmod p$ is solvable if and only if both or neither of $x^2\equiv a\pmod{p}$ and $x^2 \equiv b \pmod p$ are solvable.


How to make something similar to Excel's vlookup function in Unix?  excerpt from office website,      The V in VLOOKUP stands for vertical. Use VLOOKUP instead of HLOOKUP   when your comparison values are located in a column to the left of the   data that you want to find.      Syntax VLOOKUP(lookup_value,table_array,col_index_num,range_lookup)      Lookup_value    The value to search in the first column of the table   array. Lookup_value can be a value or a reference. If lookup_value is   smaller than the smallest value in the first column of table_array,   VLOOKUP returns the #N/A error value.      Table_array    Two or more columns of data. Use a reference to a range   or a range name. The values in the first column of table_array are the   values searched by lookup_value. These values can be text, numbers, or   logical values. Uppercase and lowercase text are equivalent.      Col_index_num    The column number in table_array from which the   matching value must be returned. A col_index_num of 1 returns the   value in the first column in table_array; a col_index_num of 2 returns   the value in the second column in table_array, and so on. If   col_index_num is:      Less than 1, VLOOKUP returns the #VALUE! error value. Greater than the   number of columns in table_array, VLOOKUP returns the #REF! error   value.      Range_lookup    A logical value that specifies whether you want   VLOOKUP to find an exact match or an approximate match:   File1:  1GR_P1:001PI :040VG_L1 :001PO_L3 1JPI_P1:001PO_L1 1JPI_P1:001PO_L2   File2:  1JPI_P1:001PO_L1    1401UC 1JPI_P1:001PO_L2    1401UC 1HIK_P2:001ER       1402UC 1GR_P1:001PI        1402UC   Output-File3:  1GR_P1:001PI        1402UC :040VG_L1       NA :001PO_L3       NA 1JPI_P1:001PO_L1    1401UC 1JPI_P1:001PO_L2    1401UC


Transparency shader causing problems (Viewport render different than final render)

I've set up a shader to render a fire/explosion looking material, which ended up quite good when rendering in the viewport. When I hit the render button it looks completely different and I am convinced it has something to do with the transparency, but I couldn't figure out what I'm doing wrong.  I've attached some screenshots to make it easier to understand what exactly is happening. Here is some additional information (if it makes any difference):   using Blender 2.78b using Filmig Log Encoding Base color management using a hair particle system which creates multiple transparency layers using Cycles render engine rendering on GPU   Thank you for all answers in advance!


I am trying to classify groups of order 18. So far, I have shown that a group $G$ of order 18 is given by $G\cong C_9 \rtimes_{\varphi} C_2$ or $G\cong (C_3 \times C_3)\rtimes_{\varphi} C_2$.  If $G\cong C_9 \rtimes_{\varphi} C_2$, then $\mid \varphi(1) \mid$ divides $2$, so that $\varphi(1)$ is trivial or inverts a generator of $C_9$. I concluded that $G \cong C_{18}$ in the former case and $G \cong D_{18}$ in the latter case.  I am now considering the case $G\cong (C_3 \times C_3)\rtimes_{\varphi} C_2$, but I am stuck. I have found , but they do not do it the same way as me (finding the image of $\varphi(1)$ in $Aut(C_3 \times C_3)$).  Is there a way to do this using my method? My goal is to be able to do questions like this on my algebra qual without having to fiddle around. I was messing around with the fact that $Aut(C_3 \times C_3)\cong GL_2(C_3)$.


Trying to search for multiple file extensions in command line

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


How did Obi-Wan know Darth Vader was Anakin?

As noted in  (similar, but not duplicate), Obi-Wan did know that Anakin was not dead, and that he was, in fact, Darth Vader. In , it is clear that the fact that Anakin was Darth Vader was not common knowledge at all.  So when how did Obi-Wan know Anakin had become Darth Vader? I don't recall reading any EU novels with any interaction between them.  Did he know at the time of their duel on Mustafar that Anakin was called 'Darth Vader'? If so, then he simply would have heard about Vader in other events and this is a dumb question


I would like to use an interactive Posix bash shell but the autocomplete feature doesn't work. When I type the Tab character it simply prints a tab. The tab completion works only when I'm in a non-Posix shell or in a Posix shell with Emacs input mode. I find Emacs input mode very awkward, as I am used to vi input mode. Invoking bash with the sh command doesn't help.  Here is my /etc/inputrc:  # do not bell on tab-completion set bell-style audible  set meta-flag on set input-meta on set convert-meta off set output-meta on  # Completed names which are symbolic links to # directories have a slash appended. set mark-symlinked-directories on  set editing-mode vi set keymap vi-insert set mark-modified-lines on  $if mode=emacs  # for Linux console and RH/Debian xterm "\e[1~": beginning-of-line "\e[4~": end-of-line # commented out keymappings for pgup/pgdown to reach begin/end of history #"\e[5~": beginning-of-history #"\e[6~": end-of-history "\e[5~": history-search-backward "\e[6~": history-search-forward "\e[3~": delete-char "\e[2~": quoted-insert "\e[5C": forward-word "\e[5D": backward-word "\e[1;5C": forward-word "\e[1;5D": backward-word  # for rxvt "\e[8~": end-of-line "\eOc": forward-word "\eOd": backward-word  # for non RH/Debian xterm, can't hurt for RH/Debian xterm "\eOH": beginning-of-line "\eOF": end-of-line  # for FreeBSD console "\e[H": beginning-of-line "\e[F": end-of-line $endif


Inequality: Tell me I'm algebraically wrong

I want to prove that, $$\left| x-y\right|\geq\left| x\right| -\left| y\right|$$ I approached the problem like this af:  Since $-\left|z\right|\leq z\leq\left|z\right|$ is true for any real number $z$, we can write the same for reals $x$ and $y$: $$-\left|x\right|\leq x\leq\left|x\right|$$ $$-\left|y\right|\leq y\leq\left|y\right|$$ We can subtract one expression from the other and get: $$-(\left|x\right|-\left|y\right|)\leq x-y\leq\left|x\right|-\left|y\right|$$  And, since $-a\leq z\leq a$ is equivalent to $\left|z\right|\leq a$ (for any real number $z$), we can write the following: $$\left| x-y\right|\leq\left|x\right|-\left|y\right|$$  This is, in fact, the opposite of what I intended to prove. I know the correct derivation though. Since $-\left|z\right|\leq z\leq\left|z\right|$ is true for any real number $z$, we can write the same for $y$ and $x-y$: $$-\left|y\right|\leq y\leq\left|y\right|$$ $$-\left|x-y\right|\leq x-y\leq\left|x-y\right|$$ By adding the two inequalities, we get: $$-(\left|x-y\right|+\left|y\right|)\leq x\leq\left|x-y\right|+\left|y\right|$$ And, since $-a\leq z\leq a$ is equivalent to $\left|z\right|\leq a$ (for any real number $z$), we can write the following: $$\left| x\right|\leq\left|x-y\right|+\left|y\right|$$ Finally, we can subtract $\left|y\right|$ from both sides and voila: $$\left| x\right|-\left| y\right|\leq\left|x-y\right|$$  This equation is simply failsafe, it holds true for all real values of $x$ and $y$. I'm more curious about $\left| x-y\right|\leq\left|x\right|-\left|y\right|$. It seems algebraically correct but ho, it's experimentally BS. Try placing $x=-6$ and $y=-7$ for instance. The values for $\left| x-y\right|$ and $\left|x\right|-\left|y\right|$ are respectively $1$ and $-1$.   Total BS, no?  So where did I screw up? I must have screwed up algebraically, but where? What's so wrong about $\left| x-y\right|\leq\left|x\right|-\left|y\right|$, algebraically?


Is it possible to lose or gain magic blood?

A thought struck me while reading these questions.  Suppose there was a magical child in a pureblood family, who shows signs of being magical early and gets their Hogwarts letter on their eleventh birthday. They arrive at Hogwarts and start their education, but shortly afterwards, lose their ability to do magic. Not that they are a bad witch or wizard but they are completely incapable of doing magic. Is it possible?  Conversely, is it possible for a muggle to gain wizarding powers through teenage years, having no magical family?


I was reading "On choosing and bounding probability metrics" () and encountered the Lévy distance,defined by  $ d_L(\mu,\nu):=\inf\lbrace{}\varepsilon>0\,:\, \mu((-\infty,x-\varepsilon])\leq\nu((-\infty,x])\leq\mu((-\infty,x+\varepsilon]), \forall x\in\mathbb{R}\rbrace $  as a special case (on $\mathbb{R}$) of the Lévy-Prokhorov distance, defined by   $ d_P(\mu,\nu):=\inf\lbrace\varepsilon>0\,:\,\mu(B)\leq\nu(B^{\varepsilon})+\varepsilon,\forall \text{ measurable }B\subset\mathcal{X}\rbrace $  In the transcript it said that $d_P$ metrized weak convergence. It is clear that $d_L\leq{}d_P.$   Additionally it mentioned that $d_L$ metrizes weak convergence too, which I don't quite understand since it is only bounded from above by Lévy-Prokhorov. For it to metrize weak convergence it should have to be equivalent to $d_P$, which I don't believe it is. Or maybe I'm mistaken. Can anyone explain?  Thanks a lot.


Is a 4 GB Xbox 360 enough for installing GTA V?

I want to buy Xbox 360 but some of my friends said that it is not enough to install it. I'm a GTA fan and I think that you guys have enough time to answer me that old question. Please tell me what I can do to install it.


How do I wait for networking before running a script?

I have a .bashrc file and inside it I have added the line ~/bin/startup2.sh. This works fine if I open a terminal after startup. But when I open a terminal on reboot like , I get an error that looks like it is related to networking.     google.auth.exceptions.TransportError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:600)   Is there a way to delay the execution of this script until I get networking?  This is using a Raspberry Pi 3 B


Unable to participate in discussion in Area 51

When I tried to join a discussion in Area 51, the system said I had to log in.   So I clicked on the link to log in, and logged in. Then I tried to join the discussion in Area 51 again, and the system still said I had to log in.  What should I do?


how to fix a rig when weightpaints still dont work

hello I am working on this dragon and I used a plug-in for blender..well using this set of bones does work but it pulls in places that it shouldn't even after weight painting I was directed here even though the group I asked the same question in.. some how could not help me..here is a snapshot of it..i don't think it should pull in those places when I move that leg  I have learned some of blender on my own the past two years so I really have had no help except watching video's on youtube so if you guys have any idea's id appreciate it


Error when building a interaction SQL Query in Marketing Cloud using a semicolon

Working in Marketing cloud where we are building a query that splits apart data from a single column into 4 separate columns where the delimiter is a semicolon.   Error is displayed when doing a "check syntax"   Error message: ';' is a reserved word and may not appear in your query.   We cant change the data to use a different delimiter so wanted to know if anyone knows of a work around?   select  c.contactid as subscriber_key  , coalesce(i.Preferred_Correspondence_Name, i.[first name]) as Preferred_Correspondence_Name  , i.[email address] as email  , c.casenumber  , c.Id as case_salesforce_id  ,party.name as party  , c.LastModifiedDate as last_modified_date  , c.CreatedDate as created_date  , c.Bank_Account_Change__c as bank_account_change  ,'add' as action  ,LTrim(PARSENAME(REPLACE([c.Bank_Account_Change__c],';','.'),4)) as Party_Details  ,LTrim(PARSENAME(REPLACE([c.Bank_Account_Change__c],';','.'),3)) as Party_ID_Details  ,LTrim(PARSENAME(REPLACE([c.Bank_Account_Change__c],';','.'),2)) as Bank_Account_Details  ,LTrim(PARSENAME(REPLACE([c.Bank_Account_Change__c],';','.'),1)) as Start_Date_Details  from  ENT.Case_salesforce_2 as c  inner join ENT.RecordType_Salesforce as rt on c.RecordTypeId = rt.Id  inner join ENT.account_salesforce as party on party.id = c.accountid  inner join contact i on i.[subscriber key]= c.contactid  where  Type = 'Payments'  and Sub_Type__c = 'Bank Account Change'  and Raised_By__c = 'External'  and Origin = 'Web'  and rt.Name = 'Financial Enquiries'  and c.Bank_Account_Change__c is not null


What is the most effective way of increasing reputation and badges and how do users reach 29k or 40k in rep when rep is limited to 200 a day?


Sometimes, when reviewing certain threads (for example, 'Suggested edits') I notice that there are series of edits from user (usually, low-rep.) with very minor changes. It's obvious that it is an attempt to increase reputation with such kind of edits - and it's not difficult to reject with too minor reason for me.  But I think such edits are not useful for SO (and, as an addition, this causes load to reviewers) - and, therefore, it will be useful to restrict users from suggesting edits for certain period if they have too many rejected edits already (for example, If user has 10 rejected edits today, next edit he would be able to suggest only after 24 hours)  Should we have such functionality? Same is to other review threads, I think. Something similar is discussed  - but it's different in my opinion.  Edit  is very similar discussion - my point is still different, may be - because I think automatic restriction (not only mod. involvement) will be quicker. Or may be such functionality already exists?


Should an antecedent of "everyone" take "their" or "his" or "our" as its corresponding possessive pronoun?

I am still confused about how to use the word everyone.  I have this sentence on a test:         Everyone wants to do their  part.   Everyone wants to do   his  part.   Everyone wants to do  our part.      I think the answer is version with their.


Removing files with a certain extension except one file from terminal

I need to remove all files with .gif extension except one file with name say "filename.gif". What is the optimal way to go about doing this in terminal?  The command rm *.gif removes all gif files including the file filename.gif.


How can I combine two text strings to represent the name of a command?

I want to combine one command with a text string to represent a second command. In MatLab it would be possible to concatenate these two strings into one string and evaluate this new string. However I have no clue as to how this can be done in LaTeX. See my  working example below:  \documentclass[10pt,a4paper,twosided]{article}         \begin{document}           \newcommand{\CaseID}{CaseOne}           \newcommand{\ProbabilityCaseOne}{1.00E-04}          \paragraph{The results for \CaseID}          \CaseID has probabilty  \Probability\CaseID       \end{document}   The combination \Probability\CaseID does not work as a synonym for \ProbabilityCaseOne. How can I achieve a functionality like that?


I would like to make a flowchart representing the organizational structure of the members of the company in SharePoint Online. I tried using Plumsail Org Chart Web part. I followed the installation steps, but I encountered an error at end.  Please, help me solve this problem or suggest other solutions.   This is the link for the Plumnsail Org chart:


Ubuntu 14.04 missing launcher (icons, time, wifi icon...)

Ubuntu missing launcher (icons on left side, time, wifi icon, close/minimize/maximize buttons ...)  Here is a screenshot:  There is no problem when I log in as a guest user.


Colouring and renaming items with command blocks

I'm making an adventure map and I cant seem to colour the chest's name. I know you can do this:  give @a minecraft:chest 1 0 {display:{Name:"epic chest"}}   and this:  tellraw @a {"text":"cool text","color":"gold"}   So I was wondering if you could do something like  give @a minecraft:chest 1 0 {display:{name:"epic chest",color:"gold"}   but that doesn’t seem to work. I have seen this done so I know it is possible, but I don’t know how


How do they compute the Gold and Elixir that can be looted?

How do they compute the Gold and Elixir that can be looted from a base? Is it 100% of the remaining? or the total (including the uncollected from mine)?


I'm filling out a form but 1 part takes a longer time, and it messes up the whole thing. I'm using splinter in python 2.7 on mac. I need help and any help would be helpful.


Where does the phrase “run code” or “run software” come from? Why “run”?

Historically speaking, it makes sense to me someone would say run "the computer". Early computers (not a human computer) were mechanical machines with moving parts that could achieve a velocity deemed "running" from the perspective of a human being. I don't know for sure if that is the reason why, but that seems plausible.  But why run the "program", "code" or "software"?


How is this type of medieval drawing form is called? Can this be praticed today with contemporary tools?  EDIT: hand-tools, not computer programs


I once knew a word that meant to mention something by announcing that you would not mention it. The word may be Greek; I encountered it in the study of poetry.  An example, then, from poetry, Edmund Spenser's Aegloga Quartet:  I will not match her with Latonaes seede. Such follic great sorrow to Niobe did breede.    Now she is a stone,    And makes daily mone, Warning all others to take heede.   Here the poet is publicly refusing to compare his subject, Elysa, with the goddess Latona, but in doing so (quite intentionally) makes the comparison.  This device is common in poetry, and I believe the term is most used in this regard, but is common in politics as well.


Macbook: Other Storage Growing at Insane Rates

I have an Early 2015 Macbook Pro Retina running Big Sur 11.2.3 that has been acting up lately. Essentially my "Other" storage is growing at insane rates. After rebooting, I have 145GB free on my HD free. Doing nothing, the "Other" storage grows and eventually brings me to less than 100mb in like 1.5-2 hours. I can't even backup using Time Machine. The back up says "Preparing backup" basically until my storage on my HD runs out (1.5-2 hours). Here's a few notes:  I've unchecked "Back up automatically" on Time Machine I've tried "tmutil listlocalsnapshots /" and "tmutil deletelocalsnapshots /", however, after unchecking the "Back up automatically" the localsnapshot is not created. My external harddrive that I'm trying to backup to has 500+ GB free. I've deleted every pending backup that I can find. I've downloaded DaisyDisk and found that the folder that in increasing non-stop in size is: /private/var/folders/zz/(long name)/T. I can't see inside the folder, so I have no idea what it is. But that folder definitely seems to be my problem.  What can I do? I'm getting desperate and feeling hopeless. I've read every forum/reddit post I could find but nothing seems to be working. Which files should I manually save if I try wiping my mac? This is my wife's computer she uses for work and she is currently having to restart the device every 1.5-2 hours because otherwise she is unable to do anything (due to the low storage). Any help would be very much appreciated.


Why do shell script comparisons often use x$VAR = xyes?

I see this often in the build scripts of projects that use autotools (autoconf, automake).  When somebody wants to check the value of a shell variable, they frequently use this idiom:  if test "x$SHELL_VAR" = "xyes"; then ...   What is the advantage to this over simply checking the value like this:  if test $SHELL_VAR = "yes"; then ...   I figure there must be some reason that I see this so often, but I can't figure out what it is.


Why doesn't there exist a wave function for a photon whereas it exists for an electron?

A photon is an excitation or a particle created in the electromagnetic field whereas an electron is an excitation or a particle created in the "electron" field, according to second-quantization.  However, it is often said in the literature that the wave function of a photon doesn't exist whereas it exists for an electron.   Why is it so?


If $(X,Y)$ are i.i.d. exponential then $X/(X+Y)$ follows a Beta distribution

I'm asked to show that if $X$ and $Y$ are independent exponential random variables with parameter , then  has a Beta distribution.  Up to know I had to find the new pdf or df when $Y$ was of the kind $Y=aB + c$ which I understand now. Here a hint is given to use "Law of total probability" which I've only seen in measure theory.   My guess would be to compute  using the fact that the df of exponential distribution is . I'm stuck at that step.


What do you call someone that grew up in a poor background but has became very rich?

The question is self-explanatory. A person that rose up from the american poverty line to become rich and famous.


While I update my device using software updater, I am getting following screen and then the updater paused in following screen:    Here is my locale lists, i.e. list which will display after execute locale command:    Here is a output of locale -a    Do anyone have idea how to fix it?  I have already tried the answers given over  stackoverflow question, but it didn't worked for me! :(  Edit:  After applying changes suggested in answer I am getting following error with my update-manager:    Any help would be appreciated! Thanks in advance.


How to downgrade from El Capitan to Snow Leopard?

I am not happy with El Capitan, and it is also not compatible with both music hardware and software that I have, so I want to go back to Snow Leopard on my late 2009 iMac. After installing El Capitan the CD drive on my iMac is not working, and I was unable to install Snow Leopard from it.  So I made a bootable USB that gets recognized when I hold option when the machine is booting. When I choose it, I get the white screen with the Apple logo, but it doesn't go into the installation phase. I have formatted my drive and no longer have El Capitan on it.  How can I install Snow Leopard? It looks to me(and I'm hopefully wrong about this) like El Capitan has blocked the option to downgrade to an earlier OS, and it is a bit infuriating that I am not in control of hardware that I have spent a lot of money on.


There's a huge security leak in <7.32. So I want to upgrade all my Drupal sites asap without too much worrying about breaking stuff.  But...  $ drush dl drupal-7.32 It's forbidden to download drupal core into an existing core.   This one works:  $ drush up   But that's not what I want now.  How can I only upgrade core to latest version?  drush up drupal is not sufficient on its own: (Sorry about the Dutch. You'll get the gist.)  $ drush up drupal Controle of updategegevens beschikbaar zijn ...                                                            [ok] Update information last refreshed: di, 10/14/2014 - 20:57  Update status information on all installed and enabled Drupal projects:  Naam                               Geïnstalleer  Proposed     Status                                     de versie     version  Administration menu (admin_menu)   7.x-3.0-rc4   7.x-3.0-rc4  Actueel  Drupal                             7.31          7.31         Actueel  Chaos tools (ctools)               7.x-1.4       7.x-1.4      Actueel  Service links (service_links)      7.x-2.2       7.x-2.2      Actueel  Entity API (entity)                7.x-1.5       7.x-1.5      Actueel  Google Analytics                   7.x-2.0       7.x-2.0      Actueel  (google_analytics)  Localization update (l10n_update)  7.x-1.0       7.x-1.0      Actueel  Module filter (module_filter)      7.x-1.8       7.x-1.8      Actueel  Pathauto (pathauto)                7.x-1.2       7.x-1.2      Actueel  Redirect (redirect)                7.x-1.0-rc1   7.x-1.0-rc1  Actueel  Token (token)                      7.x-1.5       7.x-1.5      Actueel  Views (views)                      7.x-3.8       7.x-3.8      Actueel  Webform (webform)                  7.x-3.20      7.x-3.21     Nieuwe versie beschikbaar    No code updates available.


Show grid or similar equivalent to showframe

I'm adjusting some text with \vfill and \vspace{}. I want a better orientation, so I think, that a package which displays a grid (or gridlines) over the hole page would be great. Or a package, what displays a X (corner to corner), to see the exact middle of the page.  Analogously to \usepackage{show frame}  UPDATE: Here my MWE, including everything, which is needed to solve my problem...  \documentclass{article}  \begin{document} dummy \end{document}


Can I choose which records are copied in a Partial Copy sandbox?

We have a partial copy sandbox that we're using for development and testing.  This is really helpful as some of our applications internally store Salesforce id's.  However, there is a limitation with the partial copy as it only brings in 10,000 records per object from the production environment.  Unfortunately some of the id's we internally store are not being brought down into our partial copy which causes errors.  The 10,000 records that it did copy over aren't needed; I realistically only need 1 or 2.  Is there any way I can achieve copying over a specific record from the production environment?


Find the real eigen value of the following matrix?

In the given matrix, only one eigen value is real. What is that eigen value ?  \begin{bmatrix}  1&  5&  4&  3& 2\\   2&  1&  5&  4& 3\\   3&  2&  1&  5& 4\\   4&  3&  2&  1& 5\\   5&  4&  3&  2& 1 \end{bmatrix}    Is there any small approach ?


Why does a Weil Divisor $ D $ on a scheme $ X $ induce a Weil Divisor $ D_{x} $ on the local scheme $ \text{Spec}(\mathcal{O}_{X,x})$?

Let $ X $ be an integral, separated noetherian scheme, and $ x \in X. $  In Proposition 6.11 of Hartshorne's Algebraic Geometry(Page 141), the author states that if $ D $ is a Weil divisor on $ X, $ then $ D $ induces a Weil divisor $ D_{x} $ on $ \text{Spec}(\mathcal{O}_{X,x}). $  I am not seeing why this follows.


Why I can't remove linux partitions on macOS Sierra

I'm trying to remove linux partition from my iMac (21.5-inch, Mid 2011) on MacOS Sierra 10.12 Beta 2, So I tried existing solutions by using Disk Utility, I tried from Recovery as well, But it says      You can not remove this volume because the previous volume can not be resized         Some  use Terminal but I have no idea about that.  I need a simplest and easiest way to remove these linux partitions and grow my mac partition.


Import/Export running GUI applications between localhost and SSH client running x11 forwarding?

I am running a Centos Linux server which I connect to using Putty/SSH with x11 forwarding enabled and an X11 server (Xming) running on the client machine...  I am able to open GUI applications from my Putty session on the client machine but when I end the x11 session the application close and any data is lost...  I have previously seen applications 'grabbed' or exported from a local UNIX server to an ssh client running X11 forwarding and once the user was done - they exported the GUI application back to the server where it continued to run...  This allowed a form of application sharing albeit with just one user running the app at a time but it was very useful...  This was on Solaris and it was a while back... is this possible on Centos Linux and if so, can you give any examples of how this works?


Why the proof by contradiction is a valid proof in Mathematics?

In logic and mathematics proof by contradiction is a form of proof that establishes the truth or validity of a proposition by showing that assuming the proposition to be false leads to a contradiction, does the proof by contradiction assume that Mathematics is consistent? What if some part of its axiomatic system is inconsistent, especially  tells us that the consistency of Mathematics cannot be proven?


Scope and Lifetime of variables inside "for" loop in c++

why these codes are showing different results :  for (int i = 0; i < 5; ++i)     {         static int n = 0;         n++;         cout<<n<<endl; // prints 1 2 3 4 5     }      for (int i = 0; i < 5; ++i)     {         int n = 0;         n++;         cout<<n<<endl; // prints 1 1 1 1 1     }   if static variable n is declared again then, why it is retaining its previous value. What exactly is happening with the scope of static variable inside "for" loop ? Why does not compiler showed error for declaring again an existing variable, during second iteration in the (first)loop ?  Also please tell why these codes are showing different result :  for(i=0;i<5;i++)     {         static int n;         n=0;         n++;         cout<<n<<endl; //Print 1 1 1 1 1     }      for(i=0;i<5;i++)     {         static int n=0;         n++;         cout<<n<<endl; //Print 1 2 3 4 5     }


Is there a way to show R2(s + 1, t + 1) > s · t .

Is there a way to show R2(s + 1, t + 1) > s · t ? The only way I know finding ramsey numbers to by graphing. But to prove the above inequality, what would be the best method?


So my question is that let's say I have a bit string of length four. If it is illegal to have 3 1's in a row and 3 0's in a row then how many bit string of this type exists  I was thinking that in total combination of bit strings of length four there is $2^4$, but in this case there is 2+2 illegal combinations so the total is   $2^4-4$ is this correct?


Is there any way to move an NPC from one house to another in Terraria?


In Windows OS I used to have 2 partitions:   partition #1: Windows OS partition #2: WorkPlace  Please take a look at my current partition set up:   Partition    | File system   | Mount Point | Flags =================================================== /dev/sda1    | btrfs         | /           | boot /dev/sda2    | extended      |             |    /dev/sda5  | btrfs         | /home       |    /dev/sda6  | linux-swap    |             |   Questions:    How do I know if all my personal files such as: videos, musics, work docs, php scripts, web templates, etc .... are been saved in sda5/home? How can I make sure Ubuntu is installed on sda1?


Proving the given quadratic form is chi-squared $k$

Suppose $\underline{X}$ is an $m$-dimensional vector following multivariate Normal distribution i.e. $\underline{X}$~$N_m(\underline{\mu},\Sigma)$ where $\Sigma$ is positive definite. Let $B$ be a symmetric $m$ by $m$ matrix, having the following properties:  $B\Sigma B=B$  $\underline{\mu}'B\underline{\mu}=0$  $trace(B\Sigma)=k$, where $k<m$   Prove that $\underline{X}'B\underline{X}$ follows chi-squared ($k$).  I proceeded a lot but got stuck in one last step where I think linear algebra is troubling me. Kindly have  a look at my "solution".  The second condition can be written as $\underline{\mu}'B\Sigma B\underline{\mu}=0\implies B\underline{\mu}=\underline{0}$ as $\Sigma$ is Positive definite. Then after a little algebra and considering condition 2, we can write $\underline{X}'B\underline{X}=(\underline{X}-\underline{\mu})'B(\underline{X}-\underline{\mu})=(\underline{X}-\underline{\mu})'B\Sigma B(\underline{X}-\underline{\mu})$ But $\Sigma$ is positive definite hence we can have a symmetric matrix $\sqrt{\Sigma}$ defined such that $\sqrt{\Sigma}\sqrt{\Sigma}=\Sigma$. Using this, we can write $(\underline{X}-\underline{\mu})'B\Sigma B(\underline{X}-\underline{\mu})=(\sqrt{\Sigma}B(\underline{X}-\underline{\mu}))'(\sqrt{\Sigma}B(\underline{X}-\underline{\mu}))$ We want to show that this follows chi-squared ($k$). Now, it is obvious that as $(\underline{X}-\underline{\mu})$~$N(\underline{0},\Sigma)$, $\sqrt{\Sigma}B(\underline{X}-\underline{\mu})$~$N(\underline{0},\sqrt{\Sigma}B\Sigma B\sqrt{\Sigma})=N(\underline{0},\sqrt{\Sigma}B\sqrt{\Sigma})$ Now, $trace(\sqrt{\Sigma}B\sqrt{\Sigma})=trace(B\Sigma)=k$ and $\sqrt{\Sigma}B\sqrt{\Sigma}$ is idempotent (verified). So its eigenvalues are only $0$ or $1$. Since its trace is $k$, there are $k$ eigenvalues with value $1$ and other $m-k$ eigenvalues are $0$. Now here is the thing I want to prove: I want to show that$\sqrt{\Sigma}B\sqrt{\Sigma}$, which is the covariance matrix, is diagonal and has only $k$ $1$'s and remaining $m-k$ diagonal entries $0$. The reason is, then I will be able to say that $k$ components of $\sqrt{\Sigma}B(\underline{X}-\underline{\mu})$ are independent standard normals whose sum of squares is our quadratic form and thus it follows chi-squared ($k$). But I really could not show that $\sqrt{\Sigma}B\sqrt{\Sigma}$ has the desired property i.e. it is diagonal with rank $k$. But this is crucial, it is the finale. If this does not happen, then some components will be correlated with each other and we cannot say that our quadratic form has chi-squared ($k$). I would really appreciate if someone helped me to prove this final part.


How to get the correct result when I use re.compile(pattern), if the pattern contains some special characters, like, (),?

I am trying to replace a string in a file using python re lib. But I failed on replacing some texts with some special characters, like, (), ?, etc. Can anyone help me look at this issue?  I attached my code in here.:  filterText = '\"' + sheet.row_values(row)[1] + '\"'; print "filterText = %s"%filterText; pattern = re.compile(filterText, re.S); replacedText = '\"' + sheet.row_values(row)[2] + '\"'; print "replacedText = %s"%replacedText;  if filterText == "English (UK)":     print "replacedText = %s"%replacedText;  fileContent = re.sub(pattern, replacedText, fileContent);


Prove that $f(x) = \cos(x)$ has a unique fixed point.

The following question comes from Chapter 6.4, Exercise 4 on page 156 in the set of notes .     Using Exercise 2 and 3, show that while $f: \mathbb R \to \mathbb R$ given by $f(x)=\cos(x)$ does not satisfy the condition of the Contraction Mapping Theorem, it nevertheless has a unique fixed point.   The "Exercise 2 and 3" mentioned in the question (which I've already done) were        Extend the Contraction Mapping Theorem by showing that if $f$ is a mapping of a complete metric space $(X,d)$ into itself and $f^N$ is a contraction mapping for some positive integer $N$, then $f$ has precisely one fixed point.   Use the Mean Value Theorem to prove the following:      Let $f: [a,b] \to [a,b]$ be differentiable. Then $f$ is a contraction if and only of there exists an $r \in (0,1)$ such that $|f'(x)|\le r$, for all $x \in [a,b]$.      Can anybody please show me how to use those to show that $f(x)=\cos(x)$ has a unique fixed point?  I know, from a Numerical Analysis course, that this fixed point can be found using a method such as Newton's Method, but I am not sure how to prove that it actually exists (and is unique).


New to Linux and trying to upgrade to ubuntu, the only download I see is ******.iso? I loaded this on an USB stick and rebooted puter but nothing, computer is set to boot from USB. HELP........


"Prove that there exist 4 people in the waiting room who all know each other..."  This is a part of a math problem. Should the "exist" be "exists" or is it correct the way it currently is?


This statement appears in code I am trying to work on. I do not understand what the # is for at the beginning of the line:      #If DEBUG Then         EventsLog.WriteToEventLog("Service Starting (version: " & versionNumber.ToString & ")", ProductNameClass.Name, EventLogEntryType.Information, EventId.DebugStart)      #Else         EventsLog.WriteToEventLog("Service Starting (version: " & versionNumber.ToString & ")", ProductNameClass.Name, EventLogEntryType.Information, EventId.Starting)     #End If


Are these two totally synonymous? Can one be used in place of the other anywhere? Are there any differences in nuance, or anything at all?


Curious on a habit I am starting to see on the trilogy. There is nothing stated on this in the FAQ so figured I would ask here. What is the policy on using a web address as your display name? Personally to me this feels more like spamming since the profile gives you a field for a web address. Just curious what others think.


Is it possible to find the joint distribution of a random vector if only the distribution of scalar many-to-one transformation is known?

Theoretical Exercise:  I'd like to derive the joint distribution $p_{\boldsymbol{X}}$ of a random vector $\boldsymbol{X} \in \mathbb{R}^K$ if only the distribution of a scalar many-to-one transfomration is known, say, $f(\boldsymbol{X}) = Y \sim p_Y$, with $Y \in \mathbb{R}_{\geq 0}$.  Is it possible to find the density $p_{\boldsymbol{X}}$? Are there any assumptions that are necessary to find $p_{\boldsymbol{X}}$? One assumption that would be OK for my specific problem at hand is, for example, a uniform distribution assumption for all vectors $\boldsymbol{x}^*$ that account for the same value $y^*$ of $Y$.  Practical Exercise:  Maybe it's best to clarify that with an example?  Say, we have $Y = \sum_{i = 1}^K \boldsymbol{X}_i$ and $Y \sim Gamma(K, \lambda)$. Is it possible to derive $p_\boldsymbol{X}$ if we assume $X_1, \dots, X_K$ to be iid? That is, is it possible to show that $X_i \stackrel{iid}{\sim} Expo(\lambda)$, for $i = 1, \dots, K$?   I found a  showing $Y = \sum_{i = 1}^K \boldsymbol{X}_i$ is Gamma distributed, if $X_i \stackrel{iid}{\sim} Expo(\lambda)$. I think I understood the method but I cannot manage to go the opposite way. So maybe I didn't. The last issue where I stuck was to find a one-to-one mapping that makes sense to compute the Jacobian.


I am stuck in a killing loop, how do I get out of it?

I have got myself stuck in a killing loop with a command block saying this: /kill (my username)  It was supposed to do it once, but instead it is killing me every second. I can't type a command in chat as I get killed before I finish it. Can you help me with this problem?


The more known proof of square root of $2$ is by contradiction when we assume it can be expressed as an irreducible fraction and later finding that it isn't irreducible, but... if we assume the same conditions for example: square root of $9$ we find that it isn't irreducible either. So, what's the trouble here?


Finding Linear Transformation Matrix $\mathbb{R}^2 \rightarrow\mathbb{R}^2$ and $\mathbb{R}^3 \rightarrow\mathbb{R}^2$

a) Let $T: \mathbb{R}^2 \rightarrow\mathbb{R}^2$ be a linear transformation such that $T(1,1) = (1,2)$ and $T(1,2)=(3,4)$. Find $T(5,8)$ and $T(3,-2)$ ?  b) Let $T: \mathbb{R}^3 \rightarrow\mathbb{R}^2$ be a linear transformation such that $T(1,0,-1) = (2,3)$ and $T(2,1,3) = (-1,0)$. Find $T(8,3,7)$?


Is the general definition for black holes wrong?

I often read the definition of event horizon of a black hole as the region where the escape velocity is bigger than the speed of light. However this would imply that if you're inside the event horizon you can -in theory- escape from black hole with constant acceleration (non-ballistic trajectories), like you can escape from the Earth's gravity with constant thrust without reaching escape velocity.  However I know that inside the event horizon, space-time is bended and distorted so every path only leads to singularity. So is the general definition of event horizon stating that it's the boundry where escape velocity is > speed of light wrong?  For example  Even in Encyclopeadia of Britannica defines event horizon as:     Event horizon, Boundary marking the limits of a black hole. At the event   horizon, the escape velocity is equal to the speed of light. Since general relativity states that nothing can travel faster than the speed of light, nothing inside the event horizon can ever cross the boundary and escape beyond it, including light.


How do I Call the Salesforce API from a Lightning Component?

I have a requirement to make a call to the  from a Lightning component. The issue I am facing is that there is currently no native support for acquiring a valid API session ID from an @AuraEnabled method in a Lightning component Apex controller.  The Lightning developer  states that a named credential can be used in order to bypass this security restriction. However, when I set up a named credential and then pass that named credential reference as the endpoint for the Metadata Service API, I am receiving the following error:     "FATAL_ERROR System.CalloutException: Web service callout failed: WebService returned a SOAP Fault: INVALID_SESSION_ID: This session is   not valid for use with the API faultcode=sf:INVALID_SESSION_ID   faultactor=".   I have found a potential  using Visualforce. However, the thread presenting this work around does not reference the "Named Credentials" feature as an option.  This  also presents the same issue where the documented named credential stops have been followed and the same error is received, but no solution has yet been offered.   I am not able to understand why the named credential feature is not bypassing the session id security measure for Lightning components.  Any input would be greatly appreciated.


What Figure of Speech is used in phrases like "sugar mugar"?

There are combinations like sugar mugar that people use in their speech while the second word has no meaning and only adds a rhythm. What is this called in English?


Confused about the theoretical origin of quadratic air drag

Though the mathematical concepts underlying quadratic  are quite straightforward (a single variable differential, just like the linear drag equation), my text book (and online text books) completely ignore the reasoning behind why the "drag" at high speeds on a trajectory through a fluid is proportional to the velocity squared. I know that this could not just be an empirical result.   Is there an intuitive reason for this (perhaps like momentum transfer or kinetic energy?). If possible, I would also like to ask for an intuitive reason behind the units $m^2/s^2.$


I would like to enable the root account on my Ubuntu installation.  I realize the security implications of this.


Prove that the function is continuous and differentiable (not as easy as it sounds imo)

From an old exam:     The not-necessary-continuous function $f: \mathbb{R} \rightarrow \mathbb{R}$ is given. We know that $|f(x)| < 1$ for all $x \in \mathbb{R}$.      Let $a(x) = (x-3)f(x)$ and $b(x) = (x-3)^{2}f(x)$.         Prove that $a$ is continuous at $x_{0}=3$   Prove that $b$ is differentiable at $x_{0}=3$      1.We need to show that left and right side limit are the same. If that's the case, the function is continuous:  $$\lim_{x\rightarrow 3^{-}}\left((x-3)f(x)) \right )= (3-3)\cdot f(3)= 0 \cdot f(3)= 0$$  $$\lim_{x\rightarrow 3^{+}}\left((x-3)f(x)) \right )= (3-3)\cdot f(3)= 0 \cdot f(3)= 0$$  Thus the function $a$ is continuous at $x_{0}=3$.  2.I will use difference-quotient for proving differentiability:  $$\lim_{x\rightarrow 3^{-}}\left ( \frac{b(x)-b(x_{0})}{x-x_{0}} \right )= \lim_{x\rightarrow 3^{-}} \left ( \frac{(x-3)^{2}f(x)-(3-3)^{2}f(3)}{x-3} \right ) =  \lim_{x\rightarrow 3^{-}} \frac{(x-3)^{2}f(x)-0 \cdot f(3)}{x-3}= \lim_{x\rightarrow 3^{-}}\frac{(x-3)^{2}f(x)}{x-3}= \lim_{x\rightarrow 3^{-}}(x-3)f(x) = 0$$  Apply same for the right side and get $0$ as well. Thus $b$ is differentiable at $x_{0} = 3$.  Did I do this task correctly or it's completely wrong..? :o


NullPointerExpection when creating new frame on my main

I am getting      Exception in thread "main" java.lang.NullPointerException       at deneme2.MainFrame.(MainFrame.java:43)       at deneme2.deneme2.main(deneme2.java:88)   C:\Users\Melih\AppData\Local\NetBeans\Cache\8.1\executor-snippets\run.xml:53: Java returned: 1   BUILD FAILED (total time: 1 second)   I have two classes one for the frame and the other one is for the code, i have done most part of it so far but however i am getting this error. however on my deneme2 class if i remove the MainFrame frame = new MainFrame(); it seems to work.   This is my denem2 class  public class deneme2 extends JFrame {  public static interface MessageOutput {      void appendMessage(String message); }  private MessageOutput msgOutput = new MessageOutput() {     @Override     public void appendMessage(String message) {         System.out.println(message);     } };  public void setMessageOutput(MessageOutput value) {     msgOutput = value; }  private Node front, rear; private int currentSize;  private class Node {      int data;     Node next; }  public deneme2() {     front = null;     rear = null;     currentSize = 0; }  public boolean isEmpty() {     return (currentSize == 0); }  public int dequeue() {     int data = front.data;     front = front.next;     if (isEmpty()) {         rear = null;     }     currentSize--;     msgOutput.appendMessage(data + " removed from the queue");     return data; }  public void enqueue(int data) {     Node oldRear = rear;     rear = new Node();     rear.data = data;     rear.next = null;     if (isEmpty()) {         front = rear;     } else {         oldRear.next = rear;     }     currentSize++;     System.out.println(data + " added to the queue"); }  public static void main(String a[]) throws FileNotFoundException {    MainFrame frame = new MainFrame();    queue.setMessageOutput(frame);     Scanner s = new Scanner(new File("list.txt"));     deneme2 queue = new deneme2();     while (s.hasNext()) {         queue.enqueue(s.nextInt());     }     s.close();     queue.dequeue(); }}   And this is my MainFrame class  public class MainFrame extends JFrame implements deneme2.MessageOutput { private JTextArea txt1; @Override public void appendMessage(String message) {     txt1.append(message); }  public MainFrame() {       JFrame frame = new JFrame();     JButton b1 = new JButton("Load Up the Que");     JButton b2 = new JButton("Add to the Que");     JTextArea txt2 = new JTextArea();      txt1.setEditable(false);      b1.setBounds(50, 100, 180, 100);     b2.setBounds(50, 300, 180, 100);     txt1.setBounds(600, 100, 300, 600);     txt2.setBounds(300, 300, 180, 100);      frame.add(b1);     frame.add(b2);     frame.add(txt1);     frame.add(txt2);     frame.setLayout(null);     frame.setSize(1000, 1500);     frame.setVisible(true);     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  }}


How to calculate $ \mathbb{Z}[x] /\langle2x-1\rangle $?

I don't understand very well the quotient, so, I do not know if calculate is the correct word, but I need to simplify the expression $$ \mathbb{Z}[x] /\langle2x-1\rangle  $$


Using articles before the subject of a sentence?

"Smartphone is very useful"      "Dog is loyal animal"   are these sentences incorrect? or do they require articles before the subjects? if yes, how to decide which article to use, definite or indefinite?


Do reactions interrupt their triggers or not?

In the Player's Handbook, it is pretty clear that reactions normally interrupt the thing that they are reacting to.    Xanathar's Guide to Everything, however, has explicitly changed all reactions to occurring after their triggers have finished resolving unless the ability specifies otherwise, and is reliant on that implicit assumption for several reaction abilities already.  This leads to contradictory interpretations of reactions that take implicit timing. How should this be resolved?   I'm particularly interested in how to resolve this in Adventurers League games, where players show up with perfectly legal characters reasonably expecting their abilities to work either way on account of owning or not owning XGE.


I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.   What are the steps to install Broadcom wireless drivers for a BCM43xx card?  I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.    lspci -vnn | grep Network showed:   Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b]      iwconfig showed:  lo        no wireless extensions. eth0      no wireless extensions.   NOTE: Answer below is updated every time new information is added and confirmed working.


I'm trying to make a custom checkbox using blocks    .checkbox-container {   height: 18px;   line-height: 18px;   margin: 0;   padding: 0;   display: inline-block;   cursor: pointer;   font-size: 14px;   position: relative;   vertical-align: middle; }  .label {   margin-left: 4px; }  .input-box {   display: inline-block;   height: 18px;   width: 18px; }  .off {   background-color: #fff;   border: 2px solid red; }  .on {   background-color: red;   border: 2px solid transparent; }  .on::after {   content: '';   position: absolute;   left: 6px;   top: 2px;   width: 7px;   height: 11px;   border: solid #fff;   border-width: 0 3px 3px 0;   -webkit-transform: rotate(45deg);   -ms-transform: rotate(45deg);   transform: rotate(45deg); }
      Checkbox
     How can I center the text vertically in this block?


I have a form that has multiple fields, and for testing purposes is there a way I could print out the values entered in all the fields, without having to individually print each value.


Overlapping screen when opening a question while Achievement is open on Android app

I just noticed a bug in the Stack Exchange Android app. A question is displayed incorrectly if the Achievements drawer is already open when the app loads a question. It looks like this:    To reproduce:   Open the Stack Exchange app, and tap the Achievements icon from the top. Leave the app without closing, then try to open a question from external source (e.g. search result, web browser, or Hot Network Question widget)   For reference, I'm running Android 5.1 on a Nexus 5, and the app version is 1.0.68.


How can I get JSON content from external file with pure Javascript?

I am developing a project that will have a table with a lot of content and I want to get the JSON content from an external file ("products.json") to have an better data organization.  Here is my Javascript file...  var domStructure = "";     jsonObj = {     "products": [     {         "ID": "01",         "Name": "John",         "Status": "Published"     },     {         "ID": "02",         "Name": "Paul",         "Status": "Published"     },     {         "ID": "03",         "Name": "Nick",         "Status": "Blacklist"     }], };  function getTableRow(id, name, status) {     return '\
\             ' + id + '	\             ' + name + '	\             ' + status + '	\
'; }  for(var key in jsonObj.products) {     domStructure += getTableRow(jsonObj.products[key].ID, jsonObj.products[key].Name, jsonObj.products[key].Status); }  document.getElementById('table').getElementsByTagName('tbody')[0].innerHTML = domStructure;


Can I ready an action before combat, and then use it immediately after, or just before combat starts?

I'm aware that you can use an action in combat in order to ready a specific response to be performed as a reaction when a certain event triggers it.   But what if I'm in a situation where combat hasn't begun, and want to ready an action?  Take this situation for example   I approach bandits in a tavern (No combat yet) I confront them and sense that things are about to get violent So I ready a firebolt spell (Before Initiative Rolls) and set it to trigger as my reaction when I see one of them draw their weapon   But since combat hasn't started yet, and I'm in no position to ambush, can I get a head start by readying an action before SHTF.  And if so can I set it to trigger as a reaction to them drawing their swords to begin combat, and fire at one of the bandits before they can react  What happens? Does it count as some sort of opportunity attack, or does it trigger as an bonus/extra attack/reaction/action on my first turn. or is it something else entirely?  In other words, do I have to be in combat in order to take the "ready" action, or can I do so before initiative has been rolled and still gain its benefits.   If I can take the action it before initiative is rolled, does my readied action trigger immediately after the bandit draws his weapon (as described above) or what?


I'm doing a simple program and I'm using templates in C++ to implement a library with a few data types when I don't find the way to compile it.  The code is:  VectorT.cpp file:  template <class T> VectorT<T>::VectorT(){   elementos = NULL;   numElementos=0; }   VectorT.h file :  #ifndef __VectorT_h__ #define __VectorT_h__  template <class T> class VectorT{    private:      T * elementos;     int numElementos;    public:      VectorT(); };  #include "VectorT.tpp" #endif   And the compile way, with the error:  g++ -c -o obj/VectorT.o src/VectorT.cpp -I include/VectorT.h  g++: warning: src/VectorT.cpp: linker input file unused because linking not done   Any idea? Thank you so much.


Design issue on Stack Overflow company team page

I recently visited the , and observed an anomaly! If you scroll down to the bottom of the page, you will see it on the left bottom of the page. The navigation div on the left begins to float over the footer div when one scrolls past the last row of team members. This animated GIF might help see it clearly.    The correct behaviour I think is the navigation div also moves up along with the last row of team members as it scrolls past that row.


get the value of a record in lightning component (switch between 2 components)

In a lightning component, I have a picklist that display some Article__c. In the controller js I can get the value of the selected Article__c like this :   In the component :   <aura:handler name="init" action="{!c.doInit}" value="{!this}"/> <aura:registerEvent name="articleDetail" type="c:Z_ArticleToDetailEvent"/>  <ui:inputSelect change="{!c.onArticleChange}" aura:id="selectedArticle" >     <aura:iteration items="{!v.lstArticles}" var="article">         <ui:inputSelectOption label="{!article.Name}" text="{!article.Id}" />     </aura:iteration> </ui:inputSelect>   In the controller js :  var selectedArticle = component.find('selectedArticle').get("v.value");   But I'd like to transform this picklist into a common list like that :  <aura:iteration items="{!v.lstArticles}" var="article">

{!article.Name}

{!article.Prix__c}

     </aura:iteration>   And the problem is that in the controller I cant use the get("v.value") on the element (I get a javascript error). So I search a way to get the value of the Article__c I click. After the click on the object, I display it in another component, and for that I use an event like that :   <aura:event type="APPLICATION"> <aura:attribute name="article" type="Article__c"/>     So I need to get the value of the object.  Thanks


According to     $ sudo wget http://master.dl.sourceforge.net/project/d-apt/files/d-apt.list -O /etc/apt/sources.list.d/d-apt.list --2018-03-18 21:39:27--  http://master.dl.sourceforge.net/project/d-apt/files/d-apt.list Resolving master.dl.sourceforge.net (master.dl.sourceforge.net)... 216.105.38.12 Connecting to master.dl.sourceforge.net (master.dl.sourceforge.net)|216.105.38.12|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 85 [application/octet-stream] Saving to: ‘/etc/apt/sources.list.d/d-apt.list’  /etc/apt/sources.list.d/ 100%[==================================>]      85  --.-KB/s    in 0s        2018-03-18 21:39:28 (4.05 MB/s) - ‘/etc/apt/sources.list.d/d-apt.list’ saved [85/85]  android@android:/$ sudo apt-get update && sudo apt-get -y --allow-unauthenticated install --reinstall d-apt-keyring Hit:1 http://np.archive.ubuntu.com/ubuntu artful InRelease Hit:2 http://np.archive.ubuntu.com/ubuntu artful-updates InRelease                                  Hit:3 http://np.archive.ubuntu.com/ubuntu artful-backports InRelease                                Ign:4 http://dl.google.com/linux/chrome/deb stable InRelease                                        Get:5 http://security.ubuntu.com/ubuntu artful-security InRelease [78.6 kB]                         Hit:6 http://ppa.launchpad.net/christian-boxdoerfer/fsearch-daily/ubuntu artful InRelease           Ign:7 http://download.opensuse.org/repositories/home:/manuelschneid3r/xUbuntu_17.10  InRelease      Hit:8 http://dl.google.com/linux/chrome/deb stable Release                                          Get:9 http://download.opensuse.org/repositories/home:/manuelschneid3r/xUbuntu_17.10  Release [1,014 B] Get:10 http://master.dl.sourceforge.net/project/d-apt d-apt InRelease [4,878 B]                     Hit:11 http://ppa.launchpad.net/haraldhv/shotcut/ubuntu artful InRelease                            Err:10 http://master.dl.sourceforge.net/project/d-apt d-apt InRelease            The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EBCF975E5BA24D5E Hit:14 http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu artful InRelease Hit:15 http://ppa.launchpad.net/libreoffice/ppa/ubuntu artful InRelease         Hit:16 http://ppa.launchpad.net/system76/pop/ubuntu artful InRelease            Reading package lists... Done                       W: GPG error: http://master.dl.sourceforge.net/project/d-apt d-apt InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EBCF975E5BA24D5E E: The repository 'http://master.dl.sourceforge.net/project/d-apt d-apt InRelease' is not signed. 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.


Serana disappeared during dawnguard questline.

I am doing the Dawnguard questline and I was getting the last elder scroll from septimus sigmus.   I told her to wait while I was doing stuff with the lexicon as she kept getting in my way.  She did however follow me out when we were finished we then went to the dawnguard to talk to the moth priest and we now have to find a moth priests knife.   I went to Riverwood to feed and I'm not sure if she went there with me or not but I have not been able to find her at all throughout the rest of my game play. Nothing on google has helped me it's like she has just vanished from the game even though I still need her for quests.


Sum of Infinite Series not converging. — why?

Why does the term in this  equal to infinity.  I thought when a term goes to zero the sum of all the terms added over a series goes to a specific value.   What do I miss?


How to return multiple parameter with function prototype

The definition is only returning the y param, I am just learning function prototype  #include <iostream> using namespace std;      int doDateofBirth(int m , int d , int y);      int main(){          cout << "My DoB is, " << doDateofBirth(4,14,1998) << endl;       }      int doDateofBirth(int m,int d,int y){         return m,d,y;     }


Remove 'Administrator' account Windows 10

I have trouble removing the administrator account from my notebook. It was created when I wanted to access some read-only files and I wrote "net user administrator active" in cmd. (didnt work out tho) I tried removing it but there is not an option to do so. The delete account button is not available in user settings and I can not remove it from the settings menu. It seems that its not a real account but when I turn the notebook on I have the option to sign into that account. Any ideas? thx


"I don't agree" button on "STOP! Look and Listen" page

Sometimes I fail in review audits that I don't agree with. I guess it's at least the third time where I go back to the post I reviewed and do my vote anyway - the vote I have been blamed for.  . (Unfortunately I don't have the previous examples at hand. I'll extend the list when I stumble upon the next one.)  I've already closed a few of these "why doesn't this feature or that function exists in xy"? In the past, they have been closed as "not constructive". Now they are "opinion based" or "off topic". Sometimes there is a good reason and a valid answer. In most cases there is none. Looking at the answers here, there is none. However, I decided to vote to close this question. It was an audit, I failed, I had to go the question again and vote to close it there as "primarily opinion based".  But I have to press on the "I understand" button. The problem is, I don't understand.   (I started to go to the question before I do anything in a review, to discover audits and to vote safely. Because I don't agree with many audits. I mean, the audits should be there to discover bad reviewers, not to force people to do workarounds.)  Proposal: There should be a "I don't agree" button. Pressing that doesn't just make the audit happy, this would obviously be too easy. It should trigger an "auditor" to check the audit again. It would be nice to get an explanation what I do wrong. Or accept my vote.  Alternative: Reviews are democratic. It is expected that reviewers have different opinions. So audits shouldn't blame reviewers to have another opinion. Audits should be very clear and a vast majority of the reviewers should do the same. Only such audits could be kind of fair.  The same audits should probably be used to test many reviewers. This way the quality of the audit would also be tested by the community.


I am making a magazine that is due to be printed tomorrow. I am working in InDesign and need to export it to a PDF (Print) for printing.  It needs to have a 3mm bleed.  I have done this, and checked the 'crop marks' and 'bleed marks' on the export settings - but the double page spreads are showing up strangely: one sliver of the opposite page shows on each page. I've attached a screen shot to show what I mean  I don't know if this is normal, but I presume it won't print correctly like this? What do I need to do to fix this?


I'm trying to find outliers in this mixed model:  m1 <- lmer(y ~ service + lectage + studage + (1|d) + (1|s), data=InstEval)   So I used the merTools REsim function  reEx <- REsim(m1)   and plotted reEx  p1 <- plotREsim(reEx)   but how can I find which observations are the actual outliers?


Does a comment on deleted posts count towards badges?

I've read a post on meta about .  But, I need to clarify the thing that whether the comments on a deleted post be counted towards badges(commentator, pundit).  I can't see those comments in my profile, but, those comments could be visible on the deleted posts.


How to prove that ├ (¬¬φ⇒φ) and ├ (φ⇒¬¬φ) based on deduction and/or proof by contradiction?

EDIT: someone just showed my the typo in the lecture notes. instead of:  {¬¬φ,φ}├ φ {¬¬φ,φ}├ ¬φ   it should be:  {¬¬φ,¬φ}├ ¬¬φ {¬¬φ,¬φ}├ ¬φ   than by the third form of proof by contradiction we get that:  {¬¬φ}├ φ   and by deduction:  ├ (¬¬φ→φ)   ORIGINAL POST: Given Hilbert system and:  Deduction:  K∪{ψ}├ φ iff K├ (ψ⇒φ)   Proof by contradiction:  For every φ,ψ – {ψ,¬ψ}├ φ Inconsistent set proves every verse If K∪{¬φ} is inconsistent then K ├ φ   How can it be proven that:  ├ (¬¬φ⇒φ) ├ (φ⇒¬¬φ)   I am studying from a lecture note that claims the set {¬¬φ,φ} is inconsistent because:  {¬¬φ,φ}├ φ {¬¬φ,φ}├ ¬φ   But I can’t prove {¬¬φ,φ}├ ¬φ and frankly don’t see why it should be true given that ¬¬φ is supposed to be equivalent to φ – that is what we are trying to prove after all, so why would two equivalent verses prove their negation? I will be grateful for every proof of the above mentioned, but if it is possible to confirm or deny the proof from my lecture notes (not mine, actually. I should hope I wouldn’t need help understanding my own notes. In fact they were written by a teacher, but are known to contain some typos) I will be especially grateful.   I do not study in English so I may have created some bad or non-conventional translations, for which I apologize.  EDIT: as per @GitGud's request, here is a screenshot of the notes (the text is in Hebrew but I think the math notation is clear even without the text):


I forgot my sudo password, which is always asked for when I carry out any download in terminal. So I am unable to download any software.  Though I reset in recovery mode, again it's showing 'wrong password'. Please help me to solve this.


For Diffie-Hellman, must g be a generator?

Due to a number of recently asked questions about Diffie-Hellman, I was thinking this morning: must $g$ in Diffie-Hellman be a generator?  Recall the mathematics of Diffie-Hellman:  Given public parameters $p$ (a large prime) and $g$ (always referred to as a generator of $\mathbb{Z}^*_p$).   Alice chooses $a$ at random and sends $A \gets g^a \mod{p}$ to Bob. Bob chooses $b$ at random and sends $B \gets g^b \mod{p}$ to Alice. Alice computes $S \gets B^a \mod{p}$ Bob computes $S \gets A^b \mod{p}$   From the math above, I don't see anything that would require $g$ to be a generator, so the math should work even if $g$ is not a generator.  As far as security goes, clearly having $g$ be a generator is best as $|g|$ (or the order of $g$) will be greatest when $g$ is indeed a generator. Is that the only reason for choosing $g$ to be a generator?


I am solving the following : Vector space  $\mathbb{R}$ over rational number   $\mathbb{Q}$ is infinite dimensional.  I proved this by using that $\mathbb{R}$  is uncountable, but my professor suggested a following slightly different method : Suppose that this vector space is finite-dimensional and let {$r_1,...,r_n$} be a basis for it. Then find an element in $\mathbb{R}$ which doesn't belong to $\operatorname{Span}${$r_1,...,r_n$}. I've tried several methods, but it vain. How can I prove this?


Are there any long term RC4 bias based exploits?

The RC4 cipher possibly exhibits low level bias in it's long run PRNG keystream.  I'm specifically excluding short term bias attacks which I'm defining as outputs < 1024 bytes.  Are there any real world attacks that exploit this feature?


Is the exponential map ever not injective?

Let $G\subseteq GL_n(\mathbb R)$ and let $\mathfrak g$ denote its Lie algebra.  Let $e: \mathfrak g \to G$ be the map $X \mapsto e^X$.     Does there exist an example of $G$ and $\mathfrak g$ such that $e$ is   not injective?   Of course I think the answer is no, there is no such example because $e: \mathbb R \to \mathbb R$ is injective.      What about $G\subseteq GL_n(\mathbb C)$?   Since the map is the same I again think there should not exist such an example.


Replicate a particular presentation style with Beamer

Is there any idea how can one create the style of the following presentation with Beamer     Below a screenshot of the first two pages of the presentation for reference.


Do Enchantments on Weapons Scale with Sneak Attack Bonuses?

Recently I've built a character on Skyrim who focuses mainly on sneaking and bursting to death any enemy and I'm trying to max out my damage. I have been testing what I already have and with sneaking + 2 daggers I've one shot Sahloknir and Arngeir. My current build is Ebony Dagger + Blade of Woe x30 (x15 With Daggers Perk x2 for Jesters Gauntlets/Shrouded Gloves) which adds up to 1140 damage, but this lead to my question. Do enchantments like Absorb Health and Frost Damage scale with the x30 Sneak Attack, I'm just trying to max my damage. Any help would be appreciated, thanks.


Does a single photon's energy depend on frequency? (photoelectric effect)

Essentially this question boils down to "why does the energy of light depend on frequency?".    The analogy my textbook (pg. 272 principles of chemistry A molecular Approach 3rd edition by Nivaldo J. Tro) gave was that photons with higher frequency are like baseballs, whereas photons with lower frequency are like ping pong balls. Meaning that each photon has higher energy.  This StackExchange page () seems to say the opposite, that the energy of each photon is the same and what changes is the amount of photons per area.


Change "reopen" to "leave open" in Close Votes queue

It seems that "reopen" should be changed to "leave open" in Close Votes queue tips box:    since there's no option as "Reopen" but "Leave open" has.


Inside a Nintendo Switch I spotted some traces that take a meandering path to the RAM chips.    What are the benefits of designing it this way, instead of taking the shortest path?


I have the following code:  #include <stdio.h>  int main(void) {     char c1  = 'A';     int size1;     int size2;      size1 = sizeof(c1);     size2 = sizeof('A');     printf("%d %d\n", size1, size2);     return 0; }   The output of the above code is 1 4. My question why 'A' in sizeof('A') is promoted to a integer, while c1 in sizeof(c1) is not promoted to a interger?


setting all elements of string array to one fixed length

I have a string like  String[] toppings = {"1234", "56789", "123456"};  for each element of toppings I need to check the length, and if it is less than 9, I need to add zeros at the end.  for example consider first element of the array, it is 1234. Its length is 4, so I need to add 5 zeros at the end which looks like "123400000".  similarly I need to do it for all the elements present in toppings.  And finally at the end I need to concat all the vales present in toppings to one string. Means my output must look like String x = "123400000567890000123456000".  Any suggestions?  Thanks,


$n + 1$ numbers are picked at random from $2n$ integers $1, 2, 3,\dots , 2n$?

$n + 1$ numbers are picked at random from $2n$ integers $1, 2, 3, \ldots, 2n$. Prove that among the numbers picked we can find at least two, one of which is divisible by the other.  If we try to chose numbers from the right most end from 2n and the approach n we see that there are two pairs of numbers n, 2n and n-1, 2n-1 which satisfy this.  Similarly, I have tried some possibilities, all of them satisfy but I am not able to think of a proof.  Also, this problem is given on the chapter titled "Arithmetic of Integers" that is, related to Number Theory. I don't know anything about Combinatorics except Permutations and Combinations.  Can somebody provide me a hint?  Any help would be highly appreciated.  Edit:— I've just realized that this problem is to be proven via mathematical induction. I would be greatly thankful to anyone who would provide me a solution via induction.


Extracting multiple phone number types using regex

My current code finds all cases where '+44' shows up in a website. I want this code to also produce all cases where '0131' occurs. Any help is appreciated, thank you. Code attached below.  phones = re.findall(r'\+44', page.decode()) phones.sort() print (f'\n [+] {len(phones)} PHONE NUMBERS FOUND:\n') for phone in phones: print(phone)


How to read the content of a file to a string in C?

What is the simplest way (least error-prone, least lines of code, however you want to interpret it) to open a file in C and read its contents into a string (char*, char[], whatever)?


How to prevent SQL injection and other attacks while preserving html message in PHP

I use sendgrid for sending email. I currently use following codes for validating user inputs. $string = strip_tags(stripslashes($string)); $string = mysqli_real_escape_string($con,$string); $string= htmlspecialchars($string);  I send email via sendgrid api. If i pass user generated html body and then filter/validate it, it looses all the html properties and email looks messy. If i dont filter, user might send some nasty codes which might result in various attacks. I am currently using tinyMCE for html box. Is there anything i can do to prevent SQL injection and other attacks while preserving html message in PHP.


New mix of drink with different strong alcohol

1x Beer (Alcohol-Free) 330ml. 1x Bottle of 40% Alcohol. 1x Beer (4.6% Alcohol) 330ml. This should be a very simple calculation. I have been always very bad in math, but I have improved a lot of that what it has been. I cannot find the following formula: How do I get to know how much I alcohol-free beer I have to mix with 40% alcohol in order to get same strong beer a 330ml of 4.6% alcohol.


Is there a command to factory reset Ubuntu?

I have a black screen on my PC, and I've somehow got in the terminal the terminal is all black and I can only do commands.   Is there a command to factory reset your PC through the terminal?


Ubuntu 18.04 boot stuck at "Finished Update UTMP about System Runlevel Changes"

Please find attached screenshot related to problem i started facing during boot of Ubuntu 18.04. This occurred while i restarted after Mandatory upgrade command in order of prerequisite for Ubuntu 20.04 upgrade. However i also added few PPA apt repository related to graphics and battery. Not sure of the cause. I am using Ubuntu from last 10 years. Never faced an issue like this. I have already changed my grub from "quiet splash" to "" to see the message log during startup. What is the solution required over here ?


What does the "-y" do in "yum -y groupinstall gnome"?

I've been googling and reading tutorials, but while the authors go into detail with all the things you can do with yum, no one ever mentions what the -y flag is for. I'm trying to automate this with Chef, so I needed to know what the -y does so I can determine whether to include it in my Chef recipe.


I am very new to java web applications. I am working on project from where I have to receive a specific set of images from mysql and display in jsp.   Below are my servlet code (Where I am setting my attribute, toppings contains a path of all images which are stored in my computer) and when I tried to retrive them on .jsp page it gives me an error as below:    HTTP Status 500 - An exception occurred processing JSP page /CustomerBrowseScreen.jsp at line 115      type Exception report      message An exception occurred processing JSP page /CustomerBrowseScreen.jsp at line 115      description The server encountered an internal error that prevented it from fulfilling this request.      exception      org.apache.jasper.JasperException: An exception occurred processing JSP page /CustomerBrowseScreen.jsp at line 115      112:             <%     113:                 String[] display = (String[])request.getAttribute("images");     114:                      115:                for(int i=0; i<display.length; i++)     116:                {     117:                    out.println(display);     118:                }       Stacktrace:         org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:575)         org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:477)         org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)         org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)         javax.servlet.http.HttpServlet.service(HttpServlet.java:731)         org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)     root cause      java.lang.NullPointerException         org.apache.jsp.CustomerBrowseScreen_jsp._jspService(CustomerBrowseScreen_jsp.java:193)         org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)         javax.servlet.http.HttpServlet.service(HttpServlet.java:731)         org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)         org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)         org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)         javax.servlet.http.HttpServlet.service(HttpServlet.java:731)         org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)     note The full stack trace of the root cause is available in the Apache Tomcat/7.0.69 logs.        - .jsp Code <%                 String[] display = (String[])request.getAttribute("images");                 for(int i=0; i<display.length; i++)                {                    out.println(display);                } %>   - Servlet                      String[] toppings = new String[size];                      while(rs.next())                     {                           toppings[i] = rs.getString(5);                          i++;                     }                      request.getSession().setAttribute("images", toppings);                      request.getRequestDispatcher("CustomerBrowseScreen.jsp").forward(request, response);   Please help here as it is very important .. please ..


How is $\mathcal F_\infty$ different from $\bigcup_{n=0}^\infty \mathcal F_n$?

Let $(X_n)_n$ be a sequence of random variables.  Define $\mathcal F_\infty := \sigma(X_0, X_1, \ldots)$ and $\mathcal F_n := \sigma(X_0, X_1, \ldots, X_n)$.  In the proof of the Kolmogorov's zero–one law, I came across $\bigcup_{n=0}^\infty \mathcal F_n$ and wondered in what relation it is to $\mathcal F_\infty$. In general, I don't expect $\bigcup_{n=0}^\infty \mathcal F_n$ to be a $\sigma$-algebra, yet I can't come up with a counterexample.


I read that electric field lines don't intersect. The explanation I was given goes as follows: if it happens then we would have two directions of field.  My question: since field lines are vector, then why couldn't I say that we would have direction according to vector sum? If I am right then what is the correct explanation?


Film: Aliens destroyed civilisation on Earth, captured some tribal people to train as pilots(?), resistance ensued

I remember aliens watching the tribe to know what humans eat. Hunters captured a rat, so after capture of the tribe, aliens gave them rats as food.  Some of humans were chosen to be implanted knowledge. After returning from one of procedure, human started teaching  others ("this is a triangle").  There was a simulation of flying small craft. In the first attempt s pilot decided to kill an alien by hitting the ground (but it of course was just a simulator).  Some time later humans found military planes(?). They trained fighter pilots in full-cabin simulators. I remember scene with those planes hovering behind bridge or something to hide from alien fighters.  Film ended with one of humans sacrificing himself by teleporting on top of a nuke to the alien home planet. Somehow explosion caused chain reaction that destroyed all atmosphere on that planet(?).


"the Red Cross" but no article in Greenpeace, UNICEF, or Amnesty International

In an English language textbook for Italian middle school students, there is a reading exercise where students have to fill in the gaps. Here is a completed excerpt     The International Red Cross/Red Crescent is a global charity and humanitarian organisation. It believes that people everywhere have a right to life and health. …blah, blah, blah… The Red Cross / Red Crescent began its work in 1863. Today, it operates in 186 countries and every year it gives help to about 250 million people.    My two private students had to write a paragraph about a charitable institution of their own choice. We came up with 1. Médecins Sans Frontières (in Italian Medici Senza Frontiere) which is also known as Doctors Without Borders 2.  and 3. Amnesty International. They each chose an institution and they all started their paragraphs with the definite article "the" just like in the textbook.         The Doctors Without Borders is a global charity and humanitarian…   The Greenpeace is a global charity and pacific organisation…      I crossed out the articles and said they weren't needed. Samuele asked me why–good for him–but I didn't know what to say, so I promised I would look into it.  While I can explain that the definite article is needed when we mention the  because it is a collection of states/nations, and it is omitted when it is shortened to UNICEF. I don't know why the article is needed for the  but not for  or .   I'm also aware that if the name of a company or band starts with "The" e.g. The Beatles,  The Leathersellers’ Company, and The Body Shop  the article is always obligatory and always capitalised. However, the charity's name used in the book name is , and yet the article is needed.    Is there a reason? Why is the definite article necessary in the International Red Cross, but not for Greenpeace or Amnesty International?


What device can I use to duplicate a MIFARE ISO 14443A (13.54 MHz) card?

I'm not familiar with how these devices work. I'm looking to duplicate an ID card for ease of use and this is all the information I can find on it:  MIFARE ISO 14443A (13.54 MHz)  So, is there a simple cloner or duplicator that supports this? If not, is there an arduino device or something else that can do it?  Thanks.


Component.find() Called From Child Extending an Abstract Component Fails

I was hoping to set up an abstract component with some useful markup (custom spinner and notifier components in this instance) that could be extended by other components.  The structure would be:  AbstractComponent   AbstractMarkup   Body of Extending Component  However, when I call a method on the abstract component, it is unable to find any of it's own components. I think this is an error, because it makes the abstract component much less useful.  Here is code that will replicate the issue:  TestFindAbstract.cmp  <aura:component abstract="true" extensible="true" >     <ui:outputText value="hey" aura:id="myText"/>     {!v.body} </aura:component>   TestFindAbstractHelper.js  ({     changeText : function(component) {         var text = component.find("myText");         text.set("v.value","New Text");     } })   Now, the extending class:  TestFind.cmp  <aura:component extends="c:TestFindAbstract">     <lightning:button label="Press Me" iconName="utility:download" iconPosition="left" onclick="{!c.changeText}" />  </aura:component>   TestFindController.js     ({     changeText : function(component, event, helper) {     helper.changeText(component);     } })   I would have expected the extending class to call the method on the abstract class, find the component and change the value. Instead, I get the very diplomatic error message:     This page has an error. You might just need to refresh it.   Action failed: c$TestFind$controller$changeText [Cannot read property 'set' of undefined]   Failing descriptor: {c$TestFind$controller$changeText}   Any insights would be appreciated!


I'm learning about BufferedReaders and a few other classes and am making a small program that takes a text file with information about courses I've taken and calculates my GPA. Here's what I have so far:  import java.util.ArrayList; import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException;  class GradeFormatter {      public static ArrayList<String[]> courses;     public static double unitsAttempted;     public static double unitsPassed;     public static double gradePoints;     public static double gpa;      public static void main(String[] args) {         try {             FileReader fileReader = new FileReader("grades.txt");             BufferedReader reader = new BufferedReader(fileReader);             while (true) {                 String line = reader.readLine();                 if (line == null) {                     break;                 } else {                     processLine(line);                 }             }             reader.close();         } catch (IOException e) {             System.out.println("File does not exist.");         }     }      public static void processLine(String line) {         String[] newCourse = line.split("\\t");         courses.add(newCourse);     }  }   I'm getting the following output when I try to run the program:  Exception in thread "main" java.lang.NullPointerException     at GradeFormatter.processLine(GradeFormatter.java:34)     at GradeFormatter.main(GradeFormatter.java:23)   Could anyone help me out with why I'm getting this null pointer exception? I cannot seem to figure out where it's coming from.


How to run xrandr commands at startup in Ubuntu

How can I run the following xrandrcommand on startup?  xrandr   cvt 1368 768  xrandr --newmode "1368x768_60.00"   85.25  1368 1440 1576 1784  768 771 781 798 -hsync +vsync xrandr --addmode VGA1 1368x768_60.00 xrandr --output VGA1 --mode 1368x768_60.00