A commutative ring $A$ is a field iff $A[x]$ is a PID

Wikipedia says that a commutative ring $A$ is a field iff $A[x]$ is a PID.    The "only if" part is easy: we just apply the Euclidean algorithm. I've stumbled trying to prove the "if" part, though.  $\newcommand{\aa}{\mathfrak{a}}$ My best attempt so far: suppose $\aa$ is an ideal of $A$, and $\aa'$ is the ideal of $A[x]$ spanned by $i(\aa)$, where $i: A \hookrightarrow A[x]$ is the natural embedding. $i^{-1}(\aa') = \aa$ for grading reasons ($i(A) = A[x]^0$, and multiplication by a non-zero degree polynomial takes us out of $i(A)$, because $A \cong i(A)$ is integral). $A[x]$ is a PID so $\aa' = (a')$, where $a' = i(a)$ for some $a \in A$. Therefore, $\aa = (a)$, and thus $A$ is also a PID.  That's the best way to use the fact that $A[x]$ is a PID that I've found so far. Now I feel like there must be a trick to show that if $a \neq 0$ then $a = 1$, but I don't know how to do this. Any hints?


I use subfiles package with RevTex4-1, and the main file works fine. But when I compile the subfile, I got   \bibdata{app-miNotes} No file app-mi.bbl. @CONTROL{REVTEX41Control} \citation{REVTEX41Control} @CONTROL{apsrev41Control,author="08",editor="1",pages="0",title="",year="1"} \citation{apsrev41Control} \newlabel{LastPage}{{}{0}{}{}{}} (./app-mi.aux  ./app-mi.aux:1: LaTeX Error: Missing \begin{document}.  See the LaTeX manual or LaTeX Companion for explanation. Type  H <return>  for immediate help.  ...                                                l.1 \    relax   and   warning  (pdf backend): no pages of output. Transcript written on app-mi.log. Latexmk: Non-existent bbl file 'app-mi.bbl'  No file app-mi.bbl. Collected error summary (may duplicate other messages):   lualatex: Command for 'lualatex' gave return code 1       Refer to 'app-mi.log' for details Latexmk: Use the -f option to force complete processing,  unless error was exceeding maximum runs of latex/pdflatex. === TeX engine is 'LuaTeX' Latexmk: Errors, so I did not complete making targets   What's wrong?  My subfile looks like this  \documentclass[../main.tex]{subfiles} \begin{document} \section{section title\label{appendix:mi}} some texts. \end{document}   and main file (as requested)  \documentclass[preprint,aps,prd,showpacs,superscriptaddress,nofootinbib,tightenlines,10pt]{revtex4-1} \usepackage{parskip} \usepackage{physics} \usepackage{amsmath} \usepackage{amssymb} \usepackage{xcolor} \usepackage[colorlinks]{hyperref} \usepackage{comment} \usepackage{graphicx} \usepackage{amsfonts} \usepackage[compat=1.1.0]{tikz-feynman} \usepackage{subfiles} \allowdisplaybreaks \graphicspath{{../figs/}{../../figs/}} \begin{document} \title{title} \author{name} \email{et@et} \affiliation{inst} \begin{abstract} \end{abstract} \keywords{}  \maketitle  \subfile{./subfolder/app-mi} \bibliographystyle{apsrev4-1} \bibliography{../filename.bib}{} \end{document}   also I use lualatex but other compilers (tested pdflatex and xelatex) gives the same error.   I don't know if it has anything to do with RevTex but I'll use the tag anyway.


Really really need help debugging this dpm(). It's an error from trying to create a new Message | Fixed by reinstalling Reply module

The Message module was working fine but I noticed one of the messages wasn't getting created by Rules. I suspect it's due to locale being enabled recently and creating with the UI gives this error.  For message types where I haven't created a different language, it seems to work fine.  2 errors in log:  Warning: array_flip(): Can only flip STRING and INTEGER values! in EntityAPIController->load() (line 219 of /usr/share/nginx/html/sites/all/modules/entity/includes/entity.controller.inc).   .  EntityMalformedException: Missing bundle property on entity of type message. in entity_extract_ids() (line 7930 of /usr/share/nginx/html/includes/common.inc).   The relevant lines in common.inc are:  // Explicitly fail for malformed entities missing the bundle property.     if (!isset($entity->{$info['entity keys']['bundle']}) || $entity->{$info['entity keys']['bundle']} === '') {         dpm($info);// My dpm       throw new EntityMalformedException(t('Missing bundle property on entity of type @entity_type.', array('@entity_type' => $entity_type)));     }   You can see where I added dpm(). $entity is empty but $info gives the below screenshot.   Any pointers for someone who just isn't used to debugging things like this? I've deleted every message in on the site with VBO but the error persists.   After two and half years of dev, this site was supposed to go into a proper beta next week in a friend's business but the entire UI relies on the Message module. :/    And here is a dpm of the ids for the flipping error.    Any help appreciated. I didn't expect it to all fall apart this weekend.  Edit: Closed as it is indeed a duplicate. I don't have the skills to deal with it so will just rewrite to use node functionality instead.  Edit 2: Calmed my head today and looked at things that weren't my own code. Turns out it was the Reply module which I use on Message. Reinstalling it gets rid of the errors. I don't know why it happened. It's been a part of Message for like a year during development.


If I look at a quantile plot comparing normal distribution and other data, and some of the points lie below or above the line, how do I know what that represents? What I am asking is - how do I know if the data set has a left or right skew?


Is there a way to detect the operating system in ruby? I am working on developing a sketchup tool that will need to detect Mac vs. Windows.


How do I change my username in the Stack Exchange app?

I have the stack Exchange app on my phone, but I can't seem to find out how to change my username. It's the Stack Exchange Android app version 1.0.95.


Are there consequences to stamps in my passport that are not from border control?

I’m on a trip in Japan. I've seen many touristic places that offer stamps, many temples have it as a free souvenir. This is not the first time I’ve seen this type of souvenir, I also saw the same stamps at The Tall Ships Races 2012 Lisboa. It was a big concentration of tall sails ships. There every ship had a stamp for a fake Passport, mostly for kids.  I would like to know if I stamp my passport with one of this stamps I will have problems of any kind with border security?  samples of stamps:


Do we live in a simulation?  Is the world just a hologram?  I assume that this is the same question, but see no references to holograms.  Am I correct that this is the same question?


What's a good idiom or saying to say "don't leave your current job before getting another"?

Someone asked me why I am looking for a new job while I am currently working. This got me thinking if there is a idiom that says something about it being wise to not leave your current job until you have another sure thing lined up etc.


Programs for editing Proteus gerber files to panel PCBs

I am in need of a program that lets me edit gerber zip file. I have several PCB to be sent to  but individually ordering them will cost me quite an extra (30$). Although that may not be much to some, but I don't like spending money where it can be avoided.  All that I am looking for is for me to be able to edit the board edge of my individual projects so that I can panel them in a one big square/rectangle panel.    I have tried doing it in the program I am using to create these files (PROTEUS 8.9) but it would seem there is no feature yet to combine project files. Long story short. Something will always break if I try to combine project files.  EDIT: I have tried the solutions from another question    Both of the answers did not work for me. On the marked as correct answer, no gui opens upon executing the program, if it is ment to be that way it would be really hard for me to use it. On the second answer it does come with a GUI and a guide on how to use it. Unfortunately the gerber from proteus upon creating an instance would not show up, but the gerber viewer it came along with can open it no problem


I'm a homebrewer. I use 5, 4 legged 200 liter tanks to ferment the beer.   I would love to be able to weigh the tanks and have the signal on my PLC to see how much I have in the tanks.   Each tank weighs 40kg and if it's totally packed with beer, it weighs 250kg, which means that one leg carries a maximum of 62,5kg.  I'd like to use  very cheap load cells. It is said in the documentation that if I use two I can weigh 100kg, which is enough per leg, so I would need 8 load cells per tank.   But how do I connect the load cells, and how do I get the signal up to 5 - 10 volt for the PLC?   The wires from each leg will go to a box mounted on the tank. The box shall contain the electronics needed to join signals from the 8 load cells and send a single the 5 - 10 volt signal to the analog input port on the PLC per tank.


Spotlight misses first character after Cmd-Space

When I call up spotlight by pressing command-space, and then start typing something Spotlight often seems to miss the first letter I type. It doesn't happen every time, only about 1 in 5 times I use it.  i.e. I press Cmd-Space and start to type "Finder" and instead I see "inder" in the text box.   It seems like I am not the only one with this problem   Has anyone figured out a solution for this problem?


I got and installed Steam a few months ago in my system drive. And then I got a backup of Dota 2 and installed it. It was fine till a month ago before my lap top got broken. With passing problems and finally getting my new pc and recovering a small amount of my past laptop data I found out that my Steam client has been removed.    Now the problem is that I have my Dota game folder (it's not the backup file) but I don't have my Steam client and I should reinstall it. After that am I gonna be able to play Dota again? Or should I download it from the beginning? It may not be an important thing in developed countries but in mine it is. 12GB is a huge amount for downloading!


I recently found this insect  near our veranda wall. What insect is this ? Is it poisonous?    As you can see, it has multiple legs fine as hair, but it is not like a common millipede or centipede. I searched for this insect by reverse Google image search without result.  Location: Kolkata, India  Nature: fast-moving, aggressive.  Unlike earthworms, this insect loves basking in sunlight.


Don't repeat (or let us skip) posts when requesting next page on 10k tools' Flagged Posts

I usually review the  flagged posts list, which is the one with the most pending flags by the way (most of the time around 100 flags?). It is a great way to comfortably handle those posts and contribute to the site, but it has a couple of issues that keep me from using them as much as I'd like to:  I usually flag clearly-not-an-answer posts, and just skip the ones in tags I don't have enough knowledge about, or the ones I'm not sure about how to proceed with (I'm not certain enough to flag as invalid most of the flags). This means that when I request the next page of 50 flagged posts, I see many of the posts I just skipped.   The page shows 50 posts in random order. I understand this is intentional and aimed to avoid focusing handling of the flags on specific posts based on some ordering criteria. But when we're done scrolling through the 50 posts on the list, we can only get 50 more flagged posts (), and what is worse, having repeated posts all over.  This is disencouraging me from keeping reviewing flags once I've gone through the first page of the list.  Could the Showing 50 random posts;  link avoid showing posts already shown on the current post list?  Or could we have a "Skip" option (similar to the ones on the review queues) on the flagged posts in the list, just to indicate we're not sure about them and don't want them to appear again?


How to refresh/reload an imported file on python after making changes inside that file

I am trying to refresh perhaps reload the whole file I imported on a script in which I used to changed some things within that file, and using that script to reload the file I imported within itself.  How do I refresh a file which is a script that has been imported as a module after making changes on it using the script which contains that imported file.  This is what I am trying to achieve  #lists_values.py Christine = [0,0,0] George = [900,123,1] #suppose Ralf = [ 0, 0, 0 ] is going at     this position soon.  #main.py from lists_values import * import lists_values  def insertRalf():     with open("lists_values.py", "a") as myfile:         myfile.write("Ralf = [0, 0, 0]\n")  insertRalf()  def resultView():     #Maybe some code to refresh the file I imported? Which is the lists_value since I added another list I want to print it.      #Print the NEW values of lists_values     fd = open("lists_values.py", "r")     print(fd.read())     fd.close()      #My goal is to see the new value 'Ralf', but since I imported the file when it was still unchanged, I wont see any Ralf if I print it now.  resultView()


How to get location of the element after it was clicked?

I have HTML element(span) the changes it's location.When I click HTML element(span) I need to get the HTML element(span)'s location.  Here is html:      measure            Here is onclick event:    function OpenFlyout(xpos, tbItemIndex, e)   {    }   How can I get HTML element(span) location in OpenFlyout function?


What cause my 404 error for my user_picture thumbnail in template file?

I want to print user_picture thumbnail in my page template. I am using the following code in hook_preprocess_html() in my .theme file.  $user = user_load(\Drupal::currentUser()->id()); $style = entity_load('image_style', 'thumbnail'); $variables['user_picture'] = $style->buildUrl($user->get('user_picture')->entity->url());   It's generating a URl but it is showing 404, what could be wrong here?


The word/term for a series of bad/negative events turning to a positive outcome

I tried on google every word and phrase I could come up but I just couldn't find it. I'm pretty sure I've seen this word before and it's english.


Can I sleep one of the displays on a multi-monitor setup?

I want to be able to 'put the display to sleep' on one of my two monitors when it isn't needed, so it doesn't distract me or use unnecessary power.  Ideally, the display would be asleep, but the OS would remain in dual-monitor mode, so I could still have a variety of windows open in the sleeping monitor's display space, which would mean I wouldn't have to keep switching between single- and dual-monitor modes.  That said, I'd also consider a solution that made it easy to toggle between single- and dual-monitor modes without navigating several system menus.


Null hypothesis testing of population mean $\mu = \mu_0$ against $\mu < \mu_0$

Suppose that variable $X$ is normally distributed. With sample data done from $X$, we want to do null hypothesis testing $H_0: \mu = \mu_0$, where $\mu_0$ is some constant, and $H_1: \mu < \mu_0$. True standard deviation is known as $\sigma = \sigma_0$.   When $H_1 : \mu \neq \mu_0$, I could see how hypothesis testing would go, but this time $\mu>\mu_0$ is not being considered, and I do not know how this test should be. One of my texts seems to suggest that the hypothesis testing case should be equivalent to testing $H_0: \mu \geq \mu_0$. Is this true?


In what sense are Asgardians "immortal" in the MCU?

In Thor: The Dark World, Odin and Loki are discussing Loki's actions during The Avengers.  Loki argues that he would have ruled Earth as "a benevolent god", and Odin replies:  Odin: We are not gods! We are born, we live, we die, just as humans do.  Now that's pretty definitive.  And Loki's snarky reply ("Give or take five thousand years...") would seem to confirm that Asgardians have a limited lifespan, and will eventually die of old age.1  And we know that Asgardians can die in battle, because we've seen it happen over and over with supporting characters and Asgardian soldiers. Now, I've always been more of a fan of Thor stories (like Jason Aaron's Thor: God of Thunder arc) in which Thor and the Asgardians are gods.  Straight-up, genuine, higher-level-of-existence gods, not von-Däniken-esque wannabes playing on the tired old notion of magic just being super-advanced science.  BUT, despite my preferences, this exchange would seem to confirm once and for all that in the MCU, the Asgardians are not gods, but rather were mistaken for gods because of their ram-horns full of awesome-sauce and their magnificent bulging pecks. But wait!  Watch that movie for about 30 seconds longer and we come across this exchange:  Thor: She is ill. Odin: She is mortal. Illness is their defining trait.  Wait, what?  I thought Asgardians weren't immortal?  They can die in battle, and they naturally die of old age.  In my book, that makes them long-lived, but entirely "mortal".  Surely Odin isn't splitting a hair so fine as to say that resistance to disease alone makes one "immortal"? So, if the Asgardians of the MCU aren't actually gods (grumblegrumblegrumble...), and they can't live forever (or even particularly long in a cosmic sense), and they can be killed in battle, in what sense are they "immortal" at all?  1 Fun fact: adjusted for a roughly 5,000 year lifespan, 1,048-year-old Loki is currently in the tail-end of his rebellious teenage phase.


While run in NetBeans it runs perfectly but when build and go to dist and run executable jar file report cannot run. Then I tried to run in cmd I got an error  java.lang.NoSuchMethodError: org.objectweb.asm.ClassWriter.<init> (Z) V


Error memory on Viewshed Analysis plugin QGIS

My question is exactly the same as TTome! ()  "I've been trying to test the Viewshed analysis plugin on QGIS 2.10, but it keeps giving back error messages. I've tried to reduce the radius area and have also reprojected both my DEM and my point shapefile to UTM, in order to avoid a possible memory error mentioned in another question regarding this plugin (that the using of geographic coordinates might cause a memory error). Still, I keep getting Python error messages when I try to run it. Does anyone know whats going on? Is this plugin "broken"?"  Error message:


I installed Ubuntu on my Dell laptop, but the wifi isn't working! I tried to solve the problem using different commands suggested by people on this forum, but none of them worked for me!  When I ran rfkill list all I get the following:  $ rfkill unblock all $ rfkill list all 0 : dell-wifi: Wireless LAN         Soft blocked: no         Hard blocked: yes 0 : phy0: Wireless LAN         Soft blocked: no         Hard blocked: no $ sudo rfkill unblock wifi       $ rfkill list all 0 : dell-wifi: Wireless LAN         Soft blocked: no         Hard blocked: yes 0 : phy0: Wireless LAN         Soft blocked: no         Hard blocked: no   When I saw that there is a problem with the hardware, I checked the BIOS and everything was set correctly!


What does a star with PRO in purple mean in a GitHub user account profile?

I just saw this on a GitHub account, but I have no idea what it means. How do I get one of these?


what is the difference between $(\cos A)^2$ and $\cos^2 A$

$$  (|\cos A|)^2 \qquad\text{and}\qquad \cos^2 A $$  For example if $\cos A = 0.5$, and $0.5 \times 0.5 = 0.25$, are here some difference in the notations or are they equal?


How do I generate random numbers from an array without repetition?

I know similar question have been asked before but bear with me.  I have an array:  int [] arr = {1,2,3,4,5,6,7,8,9};   I want numbers to be generated randomly 10 times. Something like this:  4,6,8,2,4,9,3,8,7   Although some numbers are repeated, no number is generated more than once in a row. So not like this:  7,3,1,8,8,2,4,9,5,6   As you can see, the number 8 was repeated immediately after it was generated. This is not the desired effect.  So basically, I'm ok with a number being repeated as long as it doesn't appear more than once in a row.


I'm interested in buying ETFs that track the US market, but because of the latest EU  regulations, I'm only allowed to purchase investment products that come accompanied by some "KID", a Key Information Document.  Fine. There are plenty European alternatives for the more popular US-based ETF. Most of them have  in their name and are denominated in EUR.  The problem is that I'm wary about the EU. Would a major downturn in EUR/USD affect the value of a EUR-denominated ETF that tracks a US index?


Recently I've witnessed some very trigger-happy down-voting on answers that had only just been posted and were still in the process of being edited. In one case I had just posted an answer with a couple of minor mistakes and within the 30 seconds it took me to edit the answer into shape I'd received two down-votes (with no explanatory comments of course). I've seen this happen to other people today too, so I don't think it's just me feeling victimized. The result of this knee-jerk down-voting is an otherwise useful answer which might as well be deleted, since no one is going to take much notice of an answer that already has a -2 rep.  So, a possible feature-request: disallow down-voting (or perhaps any voting?) until, say, 30 seconds after an answer has been posted or last edited ?


Does a big difference in sample sizes together with a difference in variances matter for a t-test (or permutation test)?

There is a very confusing question in my mind. I have data, and would like to compare numeric scores between men and women.  There is a big difference in those two groups: the number of men is 34, while the number of women is 310, and variances are not equal.  As far as I know, when the variances are not equal, I can use the Welch–Satterthwaite equation (independent t-test assuming unequal variances). My question is: can I still use this equation although there is a really big difference in sample size between my two samples? Or is there a certain limit for the difference in sample size between two samples?


Non-english characters in MySQL command-line on Windows

Table was created with:   CREATE TABLE IF NOT EXISTS `mathsqs` (        `questions` varchar(5000) NOT NULL,  ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;   I have inserted data through PHP using mysqli. To confirm the insertion, I tried SELECT * FROM mathsqs LIMIT 1 on the Windows command line. It shows question marks for non english characters.  How do I see the exact posted data in MySql command line?  Example data I'm trying to handle:     இரு எண்களின் பெருக்கல் பலன் 3375 அவ்வெண்களின் மீ.பெ.வ 15


How to add wifi firmware if I don't have make, and I basically didn't have any connection from the start?

So I've installed ubuntu on a laptop which used to run windows 10. I realized way to late that all the ethernet and wifi firmware was proprietary and default iso didn't have it. I attempted to follow this post:  but sadly I don't even have make it seems.


Icons that represent same languages / different countries?

We're re-building this app for a client and he already has several language choices, including: English (US), English (UK) and English (AU) as well as Spanish (Spain), Spanish (Latin America). Of course we're going to narrow it to English and Spanish, but wondering if there's some easily recognizable icon or concept, at least for English language.   As we're at it, I've used a football (soccer) ball for Spanish and an oval ball (American football/rugby)  for English before and it worked like a charm (kids toys), the reference is automatic. However, this is for another kind of business, so while I don't mind using a metaphor or lateral symbolism, it needs to be more "global", so to speak. But mentioning it just in case it is of help.  EDIT: Since this question seems to be kind of conflictive, I want to make clear I want to know if there's an answer for this, not on ways to do it differently, I know those ways, I want to know my SPECIFIC QUESTION and nothing else. Answers could be yes or no, with an explanation or example. Everything else not related to the exact question goes on anyone's subjectivity. Although I could be interested on subjective views on some scenarios, I'm not interested in this specific case.


Today I downloaded and installed the new  package to draw Feynman diagrams. I included the packages   \usepackage{tikz}  \usepackage{tikz-feynman} \tikzfeynmanset{compat=1.0.0} \usetikzlibrary{shapes,arrows,positioning,automata,backgrounds,calc,er,patterns}   into my preamble (changed them already many times).  However, already a simple sample code like  \begin{tikzpicture} \begin{feynman} \vertex (a) {\(\mu^{-}\)}; \vertex [right=of a] (b); \vertex [above right=of b] (f1) {\(\nu_{\mu}\)}; \vertex [below right=of b] (c); \vertex [above right=of c] (f2) {\(\overline \nu_{e}\)}; \vertex [below right=of c] (f3) {\(e^{-}\)}; \diagram* { (a) -- [fermion] (b) -- [fermion] (f1), (b) -- [boson, edge label'=\(W^{-}\)] (c), (c) -- [anti fermion] (f2), (c) -- [fermion] (f3), }; \end{feynman} \end{tikzpicture}   directly gives the error:     Package pgfkeys Error: I do not know the key '/graph drawing/node distance'.   Can you please help me? Thanks in advance!


Android 6: connect as camera per default

When I connect an Android 6 phone with my pc via USB, it always connects as "USB for charging". I have to set it to "connect as camera" (PTP) manually (for ADB to work) every time.   Can I set a default option somewhere and haven't found it yet?


Can I download all data from drupal.org?

Does drupal.org make any data dumps available for the content it hosts? I would love a full dump of module / theme / distribution data, etc. without having to scrape the site.


Lower-case roman numerals in enumerate with Spanish babel

I want to use lower-case roman numerals in a list, and I used:  %Redefine the first level \renewcommand{\theenumi}{\Roman{enumi})} \renewcommand{\labelenumi}{\theenumi}  %Redefine the second level \renewcommand{\theenumii}{\roman{enumii})} \renewcommand{\labelenumii}{\theenumii}   But I get upper-case roman numerals for both the first and the second level (I actually get smaller roman numerals for the second level).  Is there a way to use lower-case roman numerals?  Here is an example of the code I used:  \documentclass[letterpaper]{article}  \usepackage[utf8x]{inputenc} \usepackage[T1]{fontenc} \usepackage[spanish]{babel} \usepackage{parskip} \usepackage{amsmath} \usepackage{amsthm} \usepackage{mathtools} \usepackage{amssymb} \usepackage{fullpage} \usepackage{graphicx} \DeclareMathOperator{\lcm}{lcm}  \newtheorem{mydef}{Definición} \newtheorem{theorem}{Teorema} \newtheorem{lemma}{Lema} \newtheorem{proposition}[theorem]{Proposición} \newtheorem{corollary}[theorem]{Corolario} \newtheorem{remark}{Nota}  %opening \title{Tarea I} \author{Pedro     \and Mateo} \date{11 de Diciembre de 2013}  \begin{document}  \maketitle  %Redefine the first level \renewcommand{\theenumi}{\Roman{enumi})} \renewcommand{\labelenumi}{\theenumi}  %Redefine the second level \renewcommand{\theenumii}{\roman{enumii})} \renewcommand{\labelenumii}{\theenumii}  \begin{enumerate}     \item \     \begin{enumerate}         \item Muestre que $\mathbb{Q}(\sqrt[3]{2})$ no tiene automorfismos no triviales.         \begin{proof}             Dada la extensión de campos $\mathbb{Q} \subset \mathbb{Q}(\sqrt[3]{2}$         \end{proof}      \end{enumerate} \end{enumerate}   \end{document}


During cricket matches I always hear commentators to say England need 8 runs to win. Is it grammatical?


How to save a frequently used SSH host for access via terminal?

I have a host that I frequently ssh into. But I don't want to enter it again and again. Should I use an environment variable for this or is there a better way?     I wouldn't mind a generalized solution on saving frequently used variables that exist outside of a single bash session.


Six figures (3x2) on one page using subcaption package?

I want to have 6 figures on one page distributed on 3 rows and 2 columns. I've tried using \begin{subfigure} in the subcaption package without any luck. The figures are displayed correctly, but any text I add to the document is placed before the page with the figures and not after.  Any suggestions?  \begin{figure} \centering \begin{subfigure}[b]{{.5\linewidth}   \centering   \includegraphics[scale=0.37]{fig/benchmarkcase/2VF1CAD5.PNG}   \caption{5 CAD}   \label{fig:VF1CAD5} \end{subfigure}% \begin{subfigure}[b]{.5\linewidth}   \centering   \includegraphics[scale=0.37]{fig/benchmarkcase/2VF1CAD25.PNG}   \caption{25 CAD}   \label{fig:VF1CAD25} \end{subfigure} \begin{subfigure}[b]{.5\linewidth}   \centering   \includegraphics[scale=0.37]{fig/benchmarkcase/2VF1CAD50.PNG}   \caption{50 CAD}   \label{fig:VF1CAD50} \end{subfigure}% \begin{subfigure}[b]{.5\linewidth}   \centering   \includegraphics[scale=0.37]{fig/benchmarkcase/2VF1CAD75.PNG}   \caption{75 CAD}   \label{fig:VF1CAD75} \end{subfigure} \begin{subfigure}[b]{.5\linewidth}   \centering   \includegraphics[scale=0.37]{fig/benchmarkcase/2VF1CAD100.PNG}   \caption{100 CAD}   \label{fig:VF1CAD100} \end{subfigure}% \begin{subfigure}[b]{.5\linewidth}   \centering   \includegraphics[scale=0.37]{fig/benchmarkcase/2VF1CAD120.PNG}   \caption{120 CAD}   \label{fig:VF1CAD120} \end{subfigure} \caption{Volume fraction fuel phase} \label{fig:VF1BMC} \end{figure}


How can I tell if an RF transmitter is transmitting?

In my project, I use a use an  and . One of the RF components seemed to fail because the connection between my Arduinos no longer works. I cannot determine whether the RF Receiver or Transmitter works. I want to see if my RF Transmitter gives an output, but I do not own an oscilloscope to view it's waves. I've seen this , but it only shows if the Arduino is sending data to the RF Transmitter. Is there any alternative way to check if the RF Transmitter works or not? Thanks!


This is my vhost conf and still permanent redirect isn't working.  DocumentRoot /var/www/example ServerName example.com ServerAlias www.example.com <Directory "/var/www/example"> Options Indexes FollowSymLinks MultiViews AllowOverride All Order allow,deny allow from all </Directory> RedirectPermanent http://www.example.com http://example.com


How can I hide the background applications menu in GNOME?

Is it possible to place the background applications menu somewhere else? I'd prefer if it wasn't in the way of the desktop, but still easily accessible elsewhere. If not, is there at least a way to hide it?  As you can see, when it's closed it still protrudes onto the desktop in the bottom-left:  I've looked in the system settings, as well as GNOME Tweak Tool, but I can't find any settings for it. I also haven't found any GNOME extensions to solve the problem. Specs  Ubuntu 17.04 GNOME Shell 3.24.1 Arc Theme


This morning I experienced the weirdest thing by my iPhone 6S requiring me to enter my passcode rather than allowing me to use my finger as Touch ID.  My phone was locked probably for like 4 hours while charging overnight and as far as my knowledge my phone did not restart during this time since my Stack Exchange app was left open and upon opening it the same content were still there.  I didn't attempt even once to use my Touch ID; if I would've had a faulty Touch ID sensor then I should've seen such similar behavior either prior to this morning or at least afterwards (I'm already on my phone for the past 3 hours plus).  I didn't register or delete any fingerprints for months.  And finally, I don't have any restrictions setup to require the input of my passcode under Settings > General > Restrictions.  I'm running on iOS Version 10.0 beta 3 (14A5309d)  Anyone out there that has also experienced such similar behavior or with any suggestion on what might've caused it?


What is continuity correction in statistics

Can someone please explain to me the idea behind continuity correction and when is it necessary to add or subtract $\dfrac{1}{2}$ from the desired number (how do we tell whether we need to add or subtract), how do we tell when we need to use continuity correction?


Unable to alias !! (double exclamation) in bash

I was trying to create an alias in bash  alias r='!!'   My idea was to create a simple alias r to run the previous command instead of using !! (double exclamation) to run the most recent command as it is hard to type. I know I can alias r='fc -s' to make this work, but I was trying to understand why I am not able to create an alias for !!. I want to understand what !! means to bash and why I'm not able to alias it. I can create alias for other bash builtin commands like alias cdir='cd' but then why not for !! Sorry if I couldn't explain properly.


Is it correct to omit preposition before date?

Today, I received a mail from Steam and noticed that there was no preposition before the date. This is the part of the mail:     SPECIAL PROMOTION! Offer ends 26 Apr 2:00am KST   Shouldn't it be:     SPECIAL PROMOTION! Offer ends on 26 Apr at 2:00am KST   If it's okay to omit the prepositions before a date, are these sentences grammatically correct:     The gift will arrive 26 Apr 2:00am KST.   He sent the message 26 Apr 2:00am KST.   It happens every Monday 2:00am KST.


I have been taught that an electron has a wave-particle duality nature and an electron behaves as a wave when traveling.  I do also know that a wave is some kind of vibration, either it be a vibration of a vector field, or of a particle.   My questions is: If an electron behaves as a wave and a wave means some sort of vibrations, then what "kind" of vibration is/describes an electron?


How many command line arguments are there in the main function of C language?

I know for sure that there are two command-line arguments in C -- argc and argv[], but while taking an online test, I figured out that there are 3 command line arguments in C. Can someone please explain to me this.


Modular document – retrieving file with compilation error

I have a question concerning problems that can arise when compiling a modular document (multifile document). If during the compilation I get an error, how do I get the file to which the error belongs?  Thanks in advance for any feedback.


Cannot truncate table because it is being referenced by a FOREIGN KEY constraint?

Using MSSQL2005, can I truncate a table with a foreign key constraint if I first truncate the child table (the table with the primary key of the FK relationship)?  I know that I can either   Use a DELETE without a where clause and then RESEED the identity (or) Remove the FK, truncate the table, and recreate the FK.   I thought that as long as I truncated the child table before the parent, I'd be okay without doing either of the options above, but I'm getting this error:     Cannot truncate table 'TableName' because it is being referenced by a FOREIGN KEY constraint.


Variables are deleted after the session is closed

When adding a variable in export The variable is deleted automatically upon the end of the cli session or the closing of wsl abdalla@DESKTOP-9IC0VL5:/mnt/c/Users/hp$ export desk=/mnt/c/Users/hp/Desktop abdalla@DESKTOP-9IC0VL5:/mnt/c/Users/hp$ echo $desk /mnt/c/Users/hp/Desktop abdalla@DESKTOP-9IC0VL5:/mnt/c/Users/hp$ exit  C:\Users\hp>bash abdalla@DESKTOP-9IC0VL5:/mnt/c/Users/hp$ echo $desk  abdalla@DESKTOP-9IC0VL5:/mnt/c/Users/hp$  Distribution used ubuntu wsl


I'm working on a project that repUerj template needs to be used and tables, figures and graphs environments are necessarily followed by their width in parentheses as a characteristic of this template.  Ex:  \begin{table}{15cm}  ...  end{table}   The issue with this pattern is that I can't force figures, tables and graphs placement in text. I tried that using \float and \placeins but the commands from these packages simply don't work.  When I delete the width in parentheses, LaTeX returns an error messagem:     Missing number treated, as zero \end{table}   The packages used in repUerj are listed below:  \usepackage[utf8]{inputenc} \usepackage{makeidx}  \usepackage{hyperref \usepackage{indentfirst} \usepackage{graphicx} \usepackage{subfig} \usepackage{multirow} \usepackage{amsmath,amssymb} \usepackage[font=default,frame=no]{repUERJformat} \usepackage[dots=yes]{repUERJpseudocode} \usepackage[maxfloats=25]{morefloats} \usepackage{array} \setlength\extrarowheight{2pt}   concrete example:    RepUerj is available here:   Does anyone know any other alternative to use in this case?


I have a program in which I've lost the C++ source code.  Are there any good C++ decompilers out there?  I've already ran across .


the plural of the name of the letter e is ees

According to the wikipedia article of      The plural of the name of the letter e is ees (the plural of the   letter itself is rendered E's, Es, e's, es).   Therefore, is  then a regular plural formed from ?


"something." vs "something". at the end of a sentence

We're given the sentences:   The boy wouldn't finish the job due to "certain technicalities". The boy wouldn't finish the job due to "certain technicalities."   Each sentence ends with quotations. The words "certain technicalities" are not being said by a person as a sentence, so why would I enclose a period inside? It looks a little more awkward to not enclose the period, however it seems grammatically incorrect to enclose the period.  So, which is it? Is the period left inside the quotes or outside the quotes when the quotes are part of another sentence?


Volume Scatter in World makes the sky turn black

While using the "Volume Scatter" option in Blender the Background turns Black. (I am using Blender 2.79). Here is my issue in detail.  The first image below shows a normal scene with Blue sky (Set using the "World" as shown in the image)    I wanted to add mist to the scene; so i used the Volume Scatter shader and plugged it into the "Volume" node in the "World Output". The entire scene turned black and later I discovered this feature doesn't work with the "Sun Lamp" well. So I added a "Point Lamp" too in the scene. Now the mist appears. But the issue is that the blue background has entirely turned into black as shown in the image below.    I've tried changing the Strength of the "Point Lamp" but it won't help. I would request to kindly inform if anyone knows how to fix this.


Calculate the determinant of $M = \left( {\begin{array}{*{20}c} 1 & a & a^2 \\ 1 & b & b^2 \\ 1 & c & c^2 \\ \end{array}} \right)\;$.   How can one calculate this? Is there a general method like in the case of Vandermonde determinants?


Change the thumbnail/preview/top photo for albums in iOS 12

I would like to change the one photo you see for each album when you first open the Photos app.


Add small picture in margin list of figures latex

I would like to create my list of figures having a small miniature of the figure in the margin. Now my list of figures is like this . And my will is to insert a small version of the picture next to the counter, in the margin. This has been discussed , however, I want to add thumbnail in margin, not just before caption in text


Kernel loading error, `ls` at grub command line does not do anything

I was booting up my Ubuntu and I got error: /boot/vmlinuz-4.18.0-16-generic has invalid signature and error: you need to load the kernel first so I looked up on Ask Ubuntu how to solve that, and all of the posts tell me I have to use the grub command ls to show a list of partitions. When I type ls in the grub console it shows me nothing. It just steps into a new line.   I am running Ubuntu 18.10 and (if relevant) I have setup a KDE desktop on it. and yes I have tried basically ALL options that are related to this post.


Can someone explain ContextGarden's advanced document title solution?

I'm quite new to ConTeXt, and TeX in general and am hoping someone will be kind enough to explain the code in the  to me. I understand the basics, but I don't get why \setuptitle is different from \dosetuptitle, or what \v!<thing>, \c!<thing>, \??dt, etc. are. Thanks! Edit: I didn't quite do my research, ContextGarden does have  that covers my first question.


Site.createPortalUser() returning null in test context

I have a siteRegistrationController which is creating portal users as below:  Registration Controller:  public class SiteRegistrationController{      public void createPortalUser(){         //There is code to populate the values for variables u and acc.         String userId = Site.createPortalUser(u, acc.Id,null,false);             System.debug('userId is '+userId);     }  }   I am trying to test the above code and below is in my test class:  Test Class:  public class SiteRegistrationController_TEST{          SiteRegistrationController controllerObj = new SiteRegistrationController();          User guestUserObj = new User(username='testsfsdfsd@test.com',                                 IsActive=TRUE,                                 FirstName='test',                                 LastName='test',                                 Email='testsdfsd@test.com',                                 Alias='test',                                 timezonesidkey='America/Los_Angeles',                                 localesidkey='en_US',                                 emailencodingkey='UTF-8',                                 languagelocalekey='en_US');         insert guestUserObj;          System.runAs(guestUserObj){             controllerObj.createPortalUser();            } }   Site.createPortalUser is always returning null in test context.    -- This post is also about same problem but no solution here.  -- This post suggests that use the System.runAs(guestUser) but does not specify how to create guest user.   If any body has solution for this..Please help me. Thanks in Advance!


Unable to install software packages using Home Brew

I am unable to install any software packages using homebrew. I get the following error when I try to install any softwares.       Rahuls-iMac:local rahuljeevanandam$ brew install mysql     ==> Installing mysql dependency: cmake     ==> Downloading https://downloads.sf.net/project/machomebrew/Bottles/cmake-2.8.1     Already downloaded: /Library/Caches/Homebrew/cmake-2.8.10.1.lion.bottle.tar.gz     Error: SHA1 mismatch     Expected: 31856bbd662ca47c325761fc7040e43f9a635c64     Actual: 4b2ea1d2785009c32d85d1d0e0c7dc4cd68322b7     Archive: /Library/Caches/Homebrew/cmake-2.8.10.1.lion.bottle.tar.gz     (To retry an incomplete download, remove the file above.)      Rahuls-iMac:local rahuljeevanandam$ brew install wget     ==> Downloading http://ftpmirror.gnu.org/wget/wget-1.14.tar.gz     ######################################################################## 100.0%     Error: SHA1 mismatch     Expected: c487bce740b3a1847a35fb29b5c6700c46f639b8     Actual: ca98a1bf07f850bc23731fd15d869d1b73ef8c84     Archive: /Library/Caches/Homebrew/wget-1.14.tar.gz     (To retry an incomplete download, remove the file above.)


how to define a list with predefined length in Python

I want to do the following :  l = list() l[2] = 'two'   As expected, that does not work. It returns an out of range exception.  Is there any way to, let say, define a list with a length ?


I'm in doubt with one thing: let's imagine that we have $n+1$ quantities, $n$ of them being directly measured, and the other one being related to the first $n$ by a function $f : \mathbb{R}^n \to \mathbb{R}$. If the $x_i$ is one of the quantities being directly measured and if $\Delta x_i$ is it's uncertainty, then I've learned that the uncertainty of the quantity $y = f(x_1, \dots x_n)$ is given by:  $$\Delta y=\sum_{i=1}^{n}{\frac{\partial f}{\partial x_i}\Delta x_i}$$  My problem in understanding this is: well, if $f$ is such a function, it's derivative is the linear transformation $df : \mathbb{R}^n \to \mathbb{R}$ given by:  $$df=\sum_{i=1}^{n}\frac{\partial f}{\partial x_i}dx_i$$  Where $dx_i : \mathbb{R}^n \to \mathbb{R}$ is given by $dx_i(a_1 \dots a_n) = a_i$. Hence, what we are saying, is that $\Delta y = df ( \Delta x_1, \dots \Delta x_n)$, in other words, we are saying that the uncertainty of $y$ is given by a linear function of the vector of uncertainties of the quantities $x_i$. Why should that be true? I mean, what's the reasoning behind this? I really didn't get the point, my teacher just gave the equation without justifying or anything like that.  Any help and reference is appreciated.


Is there a word or phrase for when the movie tricks you for a moment like this?

I know I've noticed this effect many times but I can only think of the most recent example: At the end of a scene, someone (bad) is locked out via mechanical door, and is pressuring the people inside to let him in. As the scene is closing, and we're about to switch to a different setting, a mechanical sounds is played before the current scene is cut, but it's the audio for the next scene, making it feel like that door is opening ("Oh no"), but it's not really. You're just tricked for a moment.   Is there a word or phrase for this technique? Is this just a nuance artistic feature used by a few select directors, or is this a well known, commonly used technique?


One or more subscriptions have been marked inactive. Drop and re-create all subscriptions for this node that are failing with this error

We have a production server error causing replication agent got failed and subscription became inactive. When I tried to restart synchronizing process, it is getting failed.  Should I delete/drop the current subscription and recreate the subscription again? or does Reinitialize subscription work?  As you can see from the picture, replication from A to C is failed. How can I recteate the subscription of A from C?  Thanks Subin


How to easily make an alias command permanent?

I search everywhere and almost everyone was suggesting to open the ~/.bashrc or ~/.bash_aliases, then put the alias command there, I created a function name palias as permanent alias function and put it in ~/.bashrc:   function palias(){ echo "alias $1='$2'" >> /home/User/.bashrc;}   So now if I want to permanently alias some command I just :  palias update "sudo apt-get update"   I wonder if there is a built in command like this function, or anything like this to install from repositories?


Windows Search Indexing: Don't exclude folders with ".git" / git repositories

I index my whole data folder. After updating windows (currently on 20H2) and a new harddrive I had to select my data folder in the indexing options again. However now windows automatically excludes all those folders that contain a ".git" folder / are git repositories. This behaviour is very strange. Also took me a while to find out why I can't find my files anymore. I'm not the only one with that problem   As soon as I manually add these folders, Windows puts them back on the exclude list within seconds. Hope somebody can help me. It is no solution zipping the git folder and restoring it, when saving the code to git. PS: I've already deleted the index but that didn't help except windows was budy indexing.


How to generate thumbnails for less common video containers (mkv, ogm, mp4, flv, rmvb and mov) in windows 7 explorer?

So how to generate thumbnails for these containers? I know that the install of "" does it for MKV. But I think that only some registry changes are really necessary and I want it for other containers. If it's possible to avoiding the install of (always bloated) codecs packs it would be nice... Maybe only installing ffdshow or essential and separated codecs. (some time ago I have try reg files for vista without success...) Update: I have installed  & tweaked a little its settings and I got almost everything I want. (I have also re-installed the relevant part of the divx plus tech preview to get something else than an all black preview for MKV) Issues that I still want to resolve:  Find a cleaner & lighter method Almost all my rmvb and mov files got an all black preview (installing real media/quick time alternative doesn't help, is it the same with the officials?) With almost all containers (avi, mkv, ogm, mpg), I have (few) random files that don't get the preview. I could play them in WMP or another player and don't have found a pattern in the codecs used. All wmv, flv and mp4 have previews but I have less files in these containers.  (I clear my thumbnails cache to test them) More generally I would like to understand how windows handle the containers & codecs to generate the previews. And a software that let me choose arbitrarily the pictures previewed would be convenient too


Why Does all Linux apps (Firefox etc) not self update like Telegram?

i wonder why the apps in linux ubuntu does not self update like Telegram desktop app in linux which updates itself.


I am trying to connect a HP ENVY 5000 printer/scanner to Ubuntu 16.04 OS, the printer function works but the scanner applications say that SANE cannot detect a scanner. Any help would be appreciated


Difference between "-" and "--" prefixed command line parameters?

Scripts on command line offer a wide range of parameters types. Often parameters can be passed to the script via "--[parameter]" or "-[parameter]". But what is the difference? Why do some parameters have a double "-" and some only a single "-" prefix? Is there a convention of a technical reason behind this?  Example of possible git parameters. (See --exec-path[=<path>] vs. -c name=value)  git [--version] [--help] [-C <path>] [-c name=value]            [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]            [-p | --paginate | --no-pager] [--no-replace-objects] [--bare]            [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]            <command> [<args>]


An alternative formulation of this question is: why is the set of four axioms that define a group so fundamental, rather than, for example, the same four axioms except that associativity is interchanged with commutativity?  What makes this particular set of 4 axioms so special that abstract algebra is based on it?  The four axioms for a group $(G, +)$ are:   Closure: $\;\forall a, b \in G$, $\;(a+b)\in G$ Associativity: For all $a, b, c \in G,\,$ $\;a+(b+c)=(a+b)+c$. Identity: $\;\exists e \in G$ such that $\forall a \in G,\; a+e=e+a = a$. Invertibility: $\forall a \in G, \exists b = -a$ such that $b+a=a+b= e$.   If we add commutativity we have a commutative group. Why not for example make commutativity the key axiom and speak of an "associative group" as a special case? Or why not something else entirely?  What's so special about this combination of 4 axioms?  Edit: For example, is there a theory of "commutative non-associative magma's with an identity and inverses"?


"What happens when/if..." vs. "what will happen when/if..."

Could you tell me if there is any difference in meaning between what happens when/if... and what will happen when/if... For example:  What happens if you lose your job? Do you have a plan? What will happen if you lose your job? Do you have a plan?


Unbounded sequence has an divergent subsequence

Show that if $(x_n)$ is unbounded, then there exists a subsequence $(x_{n_k})$ such that $\lim 1/(x_{n_k}) =0.$ I was thinking that $(x_n)$ is a subsequence of itself. WLOG, suppose $(x_n)$ does not have an upper bound. By Algebraic Limit Theorem, $\lim 1/(x_{n_k}) =0.$ Is there any flaws in my proof?


Ubuntu equivalent to windows cmd command

I was just wondering if anyone knows the Linux equivalent to the " prompt" and "title" command in cmd.  Thanks


How to download and install unmet dependencies automatically

Is there any method on command line or a software that will download and upgrade/install all unmet(missing or outdated) dependencies for a package automatically. There are some packages that have missing dependencies or some times the dependent package is of old version.


Is it normal practice to write code (JS/PHP) in feature?  I was thinking that feature should contains ONLY settings, however I've read that some developers write code there and they believe it's fine.  the reason why I ask I found a video on  where they write code in feature so I'm in doubt now.  Any pros and cons to that?


I am uncomfortable with the use of inputs as the plural noun of the previously non-countable input. Is this a recent computer-related development (as used in many posts on this site) which has spilled into wider use, or is there a subtle demarcation of use happening? I am thinking especially about situations where input equates with a contribution or feedback.    For example, I've seen sentences like: 'The organisation responded to the customers' inputs', and it feels completely wrong. For me this type should always be input whether plural or not.  As an aside I am very comfortable with inputs as the plural of the sockets into which plugs can be put, but again this is a very different meaning. What is the state of play?


I want to run this command in background because the process could take a long time. How can I send it to a background process?  find /tmp/ -type f -mtime +3 | xargs rm -Rf   This does not work:  find /tmp/ -type f -mtime +3 | xargs rm -Rf &   How can I do this instead?


Installing Windows after Ubuntu without live USB or CD

I have a acer aspire es15 with preinstalled windows 10.. but i accidently deleted windows and installed ubuntu 14.04 now can I install windows 7 without deleting ubuntu as dual boot without using a live usb?? I heard of EasyBCD but does it work???


Can I Re-Assign TFS Work Items to Checked-In Code?

Is it possible to go back and tie work items to code that's already been checked into TFS? For example . . . A developer picks the wrong work item, or forgets to pick a work item? I can see work item details for ChangeSets, but the work item page is read-only.


I have seen many questions about circular reasoning on this website but none of them have satisfied my doubt. How do I know if I'm doing circular reasoning on a limit by doing l'hôpital? I do know that circular reasoning is when you use l'hôpital on a limit like $\lim_{x\to 0}\frac{\sin(x)}{x}$ because the defn of the derivative of sine is cosine which is obtained by applying l'hôpital? Yeah but how do I know exactly if whenever I want to apply l'hôpital, that same l'hôpital has been used to evaluate the derivative?


Are there linear transformations from vector spaces over different fields?

I'm in a matrix theory class, and today we started talking about linear transformations. My professor noted that the range and domain of a linear transformation must be vector spaces over the same field. This made sense to me at first because of the fields are different, then something like $T(cx)=cT(x)$ doesn't make any sense when c is only in one of the vector spaces.   But then I thought that maybe some fields might be compatible, like for example, $\mathbb{Z}_5$ and $\mathbb{Z}_7$  Are there any linear transformations for two spaces over different fields? or Are there functions that have all the same properties as linear transformations except that the spaces involved use different fields?  If the answer is no, can you prove it?


Squid isn't spawning in my farm (plz help)

I have a 15*15 farm. Its 64 to 46. full of water. It took so much time to do it. Your help will be appreciated.


Field of fractions of $\mathbb{Q}[x,y]/\langle x^2+y^2-1\rangle$

This problem goes as follows:     Prove that $\mathbb{Q}[x,y]/\langle x^2+y^2-1\rangle$ is an integral domain and that its field of fractions is isomorphic to the ring of rational functions $\mathbb{Q}(t)$.    The first part is straightforward, $x^2+y^2-1$ is irreducible in $\mathbb{Q}[x,y]$, and  hence a prime ideal, as $\mathbb[Q][x,y]$ is a euclidean and hence a UFD. The quotient by a prime ideal is an integral domain.   How do I do the second part? I guess, I have to set a isomorphism by making a substitution such that only one variable remains. But I don't see how $x^2+y^2-1$ is going to help me make a choice.


How does a photon travel the speed of light while it is absorbed in a molecule? Since photons always travel the speed of light and continue to exist after they are absorbed in a molecule that they hit, then what are the mechanics of a photon traveling the speed of light while is absorbed in a molecule?


I want to split the following list into three sublists so that each sublist will consist of three elements:  my_list = ['text1', 'text1', 'text1', 'text2', 'text2', 'text2', 'text3', 'text3', 'text3']   result should be like:  result = [['text1', 'text1', 'text1'],['text2', 'text2', 'text2'],['text3', 'text3', 'text3']]


Prove that for real number $p\geq  0$ we have   $$\lim_{n\to\infty}\frac{(1^{1^p} \cdot2^{2^p}\cdots n^{n^p})^\frac{1}{n^{p+1}}}{n^\frac{1}{(p+1)}} = \exp\left(\dfrac{-1}{(p+1)^2}\right).$$


How can I tell if a used Xbox 360 is in good condition before buying it?

I'm picking up a used Xbox 360. It isn't expensive and the seller has agreed to let me try it out first. To test it out, here's some things I'm trying to get answered:   Is it banned from Xbox Live? Is the DVD drive in good condition?   How do I check whether this particular Xbox has been banned?  Are there any other things that I should check?


Closed-form expression for $\sum_{k=0}^n\binom{n}kk^p$ for integers $n,\,p$

Is there a closed-form expression for the sum $\sum_{k=0}^n\binom{n}kk^p$ given positive integers $n,\,p$? Earlier I thought of this series but failed to figure out a closed-form expression in $n,\,p$ (other than the trivial case $p=0$).  $$p=0\colon\,\sum_{k=0}^n\binom{n}kk^0=2^n$$  I know that $\sum_{k=0}^n\binom{n}k=2^n$ and $\sum_{k=0}^nk^n=\frac{k^{n+1}-1}{k-1}$ but I am unsure of whether these would be of much use now.    Additionally, what about the similar series $\sum_{k=0}^n\binom{n}kk^n$ where $p=n$?


Idea behind "Your vote is now locked in unless this answer is edited"

I've found many questions here regarding this 'feature' and many answers explaining how it works, but none showing any 'philosophical' concept behind it. i.e., why is it here? Is it helping to make site better?  For example, just now I made a downvote, retracted it to think a bit more, left a comment with explanation and tried to downvote again. No game. And this is not the only real-life situation when value of this 'feature' is doubtful. There're plenty on this meta.  So, what was the primary reason to introduce it? A flow of people who change all their votes on daily basis?


Creating compressed GeoTIFF with QGIS Clipper tool?

I have a geo-tiff created by Pix4D which is about 375 Mb in file size.   I have clipped it to a smaller area using Qgis 2.8(using Raster ‣ Extraction ‣ Clipper), and the output file is about 900 MB in size.  Why did the clipping process generate such a large file, when the source file was smaller?   How do I run the clipper tool so that it produces a smaller size?


Isn't $HOME supposed to be the location of the user's home directory?

I'm having trouble with a web application I'm writing: The web application, which runs as user nobody, needs to launch an inkscape process to manipulate some SVG files. Because this runs as user nobody, there is no home directory. What I am doing is creating a temporary directory under /tmp and trying to set that as the home directory via export HOME=/tmp/someUniqueId. I then set a few things in that "temporary" home directory, like a symlink .fonts to the folder for the font files to use.  I know this works for finding the ~/.fonts directory. But when I launch Inkscape, all I get is a message that Inkscape could not create the .inkscape directory:    Doesn't $HOME set the location of my home directory? Why is Inkscape still trying to access / as my home directory?


.NET DataTable skips rows on Load(DataReader)

I'm trying to populate a DataTable, to build a LocalReport, using the following:  MySqlCommand cmd = new MySqlCommand(); cmd.Connection = new MySqlConnection(Properties.Settings.Default.dbConnectionString); cmd.CommandType = CommandType.Text; cmd.CommandText = "SELECT ... LEFT JOIN ... WHERE ..."; /* query snipped */  // prepare data dataTable.Clear(); cn.Open(); // fill datatable dt.Load(cmd.ExecuteReader()); // fill report rds = new ReportDataSource("InvoicesDataSet_InvoiceTable",dt); reportViewerLocal.LocalReport.DataSources.Clear(); reportViewerLocal.LocalReport.DataSources.Add(rds);   At one point I noticed that the report was incomplete and it was missing one record. I've changed a few conditions so that the query would return exactly two rows and... surprise: The report shows only one row instead of two. I've tried to debug it to find where the problem is and I got stuck at   dt.Load(cmd.ExecuteReader());   When I've noticed that the DataReader contains two records but the DataTable contains only one. By accident, I've added an ORDER BY clause to the query and noticed that this time the report showed correctly. Apparently, the DataReader contains two rows but the DataTable only reads both of them if the SQL query string contains an ORDER BY (otherwise it only reads the last one). Can anyone explain why this is happening and how it can be fixed?  Edit: When I first posted the question, I said it was skipping the first row; later I realized that it actually only read the last row and I've edited the text accordingly (at that time all the records were grouped in two rows and it appeared to skip the first when it actually only showed the last). This may be caused by the fact that it didn't have a unique identifier by which to distinguish between the rows returned by MySQL so adding the ORDER BY statement caused it to create a unique identifier for each row. This is just a theory and I have nothing to support it, but all my tests seem to lead to the same result.


How to stop Windows 10 build 9926 from installing

I'm on a brand new Dell XPS 15 and the new Technical Preview build 9926 is completely unusable. It's not compatible with my intel and Nvdia drivers and most of the time I get stuck on a black screen at boot. The only thing I can so is rollback to 9879 which works fine but that gives me about a half day before 9926 forces itself to install again. I have it set to slow now but it doesnt help. How can I stop it from installing after rollback?


A circle's area could be defined as $\pi$ times $r$ times $r.$ However, how do we get this valuation?  shows one way we can find the area of a circle. I highly encourage you to watch it as it will be vital to understand it before continuing.  In the video, they talk about how we can create a circle within the circle, and even smaller circles within that circle. Basically like an onion, with multiple rings. You would then take all the rings, and place them in such a way that it would form a triangle. The height would be the circumference, or $\pi$ times two times $r$, and the length would be $r.$  So using the two values, we can find the area of the triangle, and therefor find the area of the circle.  However, I have a question on this. When you draw out the rectangles, no matter how many there are, they should look something like this:       __  __ |  | |  ||  |   Notice the height difference? Of course, the more rectangles we create, the smaller the gap, but the gap will always be there. Does that mean, for this proof at least, that the area of the triangle is a little smaller than $\pi$ times $r$ times $r$?  And if it is, could we express it as a limit? Perhaps as the limit of the number of rectangles reaches infinity, the area becomes closer and closer to a circle's?


Off-topic popup doesn't have a 'completely off-topic' option for flags

When I flag a question as "doesn't belong here", the new 'off-topic' subcategories are great, but there's a little disconnect between the top-level blurb and the options actually displayed beneath. The headline is:     This question does not appear to be about programming, within the scope defined in the help center   and the options presented are:    All those options are about questions that the OP might feasibly have thought would be ok on SO. There isn't currently an option for 'has nothing to do with programming at all and wouldn't even be on topic on another stackexchange'.  Could an option be added to cover plain 'off-topic' questions?   Or should we treat such posts as spam even without an 'advertising' aspect?  Edit: I didn't realise 'Other' is still available in the Close vote options, which changes things somewhat (I was under the impression one of these options would have to be picked for the close message). So I am happy with the options as-is, it's only a little confusing for <3k rep users who go to flag, not a problem as such.


I'm trying to install g++ 14 after removing the existing version. the error message: $ sudo add-apt-repository ppa:ubuntu-toolchain-r/test  Toolchain test builds; see https://wiki.ubuntu.com/ToolChain   More info: https://launchpad.net/~ubuntu-toolchain-r/+archive/ubuntu/test Press [ENTER] to continue or Ctrl-c to cancel adding it.  Hit:1 http://al.archive.ubuntu.com/ubuntu focal InRelease Hit:2 http://dl.google.com/linux/chrome/deb stable InRelease                    Hit:3 http://al.archive.ubuntu.com/ubuntu focal-updates InRelease               Ign:4 http://ppa.launchpad.net/snaipewastaken/ppa/ubuntu focal InRelease        Hit:5 http://linux.teamviewer.com/deb stable InRelease     404  Not Found [IP: 91.189.95.83 80] Reading package lists... Done E: The repository 'http://ppa.launchpad.net/snaipewastaken/ppa/ubuntu focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.


Question on the relation between Transformer's primary and secondary coil current

Suppose I have a 12-0-12 1Amp step down transformer. The primary coil is connected to 220V AC. How is the current flow in primary coil impacted in following 3 scenarios:   When no load connected to secondary When 250mA is drawn from secondary  When 500mA is drawn from secondary.   If the primary coil's current flow remains unchanged regardless of the amount of current drawn from  secondary, which form of energy does the primary coil's current gets converter on no secondary load condition?  And if the current flow in primary varies, which principle of physics basically drives the factor - how much current should flow in the primary coil, for a given amount of load on secondary coil?


How do I un-install / remove a click package

I have installed some click packages on my Ubuntu Touch device. How do I remove them?


How to update length property of feature class field in ArcGIS Desktop?

I have a feature class with a string field that I want to update the length from 10 to 25.    Is there a way or a tool to update this property without having to create a new field and using field calculator to move over the records from old to new field?    This script below does what I want, the only thing is it pushes the updated field to the end of the table (not keeping the original field order).    Another option that seemed promissing is to use the Feature Class to Feature Class tool (access this tool by right clicking a layer in ArcCatolog and selecting Export>to   Geodatabase single option) .  It does create a new layer, however you can update field names and property information.  It also appears that you can change the field order using the "Move Input Field Up/Down" arrows, but they seem to not work.  There has to be a solution to just edit field properties without having to create a new field.


Why is my top answer to showing in my Top Network Posts?

I answered a question scifi that currently has 46 votes:  However, this answer is not showing up on my Top Network Posts:  Why?


Prove that $ \left(1+\frac a b \right) \left(1+\frac b c \right)\left(1+\frac c a \right) \geq 2\left(1+ \frac{a+b+c}{\sqrt[3]{abc}}\right)$.

Given $a,b,c>0$, prove that $\displaystyle \left(1+\frac a b \right) \left(1+\frac b  c \right)\left(1+\frac c a \right) \geq 2\left(1+ \frac{a+b+c}{\sqrt[3]{abc}}\right)$.   I expanded the LHS, and realized I have to prove $\displaystyle\frac a b +\frac a c +\frac b c +\frac b a +\frac c a +\frac c b \geq \frac{2(a+b+c)}{\sqrt[3]{abc}}$, but I don't know how. Please help. Thank you.


Proving no unbiased estimator exists for $\theta^{-1}$ for Poisson Dist. Why is $X_1,...,X_n = \sum{X_i}$?

Suppose that $X_1,...,X_n$ is an iid random sample from a Poisson distribution with mean $\theta$. I would like to prove that there exists no unbiased estimator of $\frac{1}{\theta}$.   To do so, I will let $\delta(X)$ be an estimator of $\frac{1}{\theta}$.   Then, I'd like to equate the expectation of $\delta(X)$ and $\frac{1}{\theta}$  E$[\delta(X)]$ = sum from x=0 to infinity of [ $\delta(x)$$P(X=x)$ ].   Now, my problem is that some books let $Y= \sum{X_i}$ and then have:  E$[\delta(Y)]$ = sum from y=0 to infinity of [ $\delta(y)$$P(Y=y)$ ].   How are these two methods equivalent? How is it that the sum of the X's some how is equivalent to $X_1,...,X_n$?  In other words, why is: $\delta(X_1,...,X_n) =  \delta(Y)=\delta(\sum{X_i})$?  Thanks!!!


Where is the fSPY .py script to add to Blender addons on Mac?

I'm trying to import a scene into blender using the Mac version of fSPY. I don't see anything in package contents or the download page to import to Blender itself so that I can import fSPY files. I've tried using the .dmg file, zipping it, zipping the windows file, digging through package contents for a .py file. Edit: The answer referenced does not help. I am on a Mac, the answers are for Windows and Linux. Zipped .dmg files do not install into the addons folder of Blender. Installing blender addons on a Mac usually requires a .py file that you manually drag over to the addons folder inside of package contents inside the blender application.


I have a few files that I accidently updated without making a backup first. I transferred (instead of copying) them to another folder and ended up overwriting the data. Is there any way to restore the files to an earlier point if Volume Shadow Copy isn't enabled?


Why is the li moving below the image after i set it to inline-block?

I am trying to create a nav bar and i don't know why i am facing this problem : Trying to set the li within the ul as inline-block works, but it is moving the whole list below the image i am using as a logo. Can someone explain why is this happening and how to fix it?    * {   margin: 0;   padding: 0;   box-sizing: border-box; }  body {   background-color: black; }  img {   display: inline-block;   width: 100%;   height: auto;   background-position: center;   background-size: cover;   background-repeat: no-repeat; }  .logo {   width: 150px;   position: center;   display: inline-block; }  #nav-bar {   background-color: yellow; }  ul {   list-style-type: none;   margin: 0;   padding: 0;   display: inline-block; }  #nav-bar li {   display: inline-block; } <!DOCTYPE html>         <meta charset="UTF-8" />     <meta name="viewport" content="width=device-width, initial-scale=1.0" />     <title>Document</title>     <link rel="stylesheet" href="style.css" />

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Prove $\sum\binom{n}{k}2^k = 3^n$ using the binomial theorem

I'm studying for a midterm and need some help with proving summation     $$\sum\limits_{k=0}^n\binom{n}{k}2^k = 3^n$$   using the binomial theorem.  This is what I've been thinking so far:   In the binomial theorem, we set $x = 0$ and $y = 2$, so:  $3^n = (x+y)^n = \sum\limits_{k=0}^n\binom{n}{k}y^k$  $ = \sum\limits_{k=0}^n\binom{n}{k}2^k$  Am I getting this correct so far or completely wrong? Any help would be appreciated. Thanks.


Does a smooth "transition function" with bounded derivatives exist?

Does there exist a function $f: \mathbb{R} \to \mathbb{R}$ having the following properties?   $f(x) = 0$ for all $x \le 0$. $f(x) = 1$ for all $x \ge 1$. For $0 < x < 1$, $f$ is strictly increasing. $f$ is everywhere $C^\infty$. The sequence of $L^\infty$ norms $\langle \left\lVert f \right\rVert_\infty, \left\lVert f' \right\rVert_\infty, \left\lVert f'' \right\rVert_\infty, \dots \rangle$ is bounded.   If we impose only the first four conditions, there is : for $0 < x < 1$, define $f(x)$ by $$ f(x) = \frac{e^{-1/x}}{e^{-1/x} + e^{-1/(1-x)}} = \frac{1}{1 + e^{1/x - 1/(1-x)}} $$ However, the derivatives of this function appear to grow quite rapidly. (I'm not sure how to verify this, but it seems at least exponential to me.)  If such a function does not exist, what is the smallest order of asymptotic growth that the sequence $\langle \left\lVert f \right\rVert_\infty, \left\lVert f' \right\rVert_\infty, \left\lVert f'' \right\rVert_\infty, \dots \rangle$ can have?


area of triangle in terms of sides ratio

In $\triangle ABC$, $X$ and $Y$ are points on the sides $AC$ and $BC$ respectively. If $Z$ is on the segment $XY$ such that $\frac{AX}{XC}=\frac{CY}{YB}=\frac{XZ}{ZY}$, prove that the area of $\triangle ABC$ is given by: $$ \text{area of }\triangle ABC=\left((\text{area of }\triangle AXZ)^{1/3} +(\text{area of }\triangle BYZ)^{1/3}\right)^3 $$


What is the spelling of program/programme

Do you say program or programme? Which one is original english? Which one should we use?


Part of what we eat are proteins, and our body is in part build of proteins.  Are the proteins of the body build based on proteins in food at all?  Are proteins in food directly reused in the body, or are proteins first disassembled?  How far are they disassembled, randomly in various pieces, or systematically to keep what can optimally be used to build new proteins, while nothing is wasted for energy?  (The question  and it's answers are related, and provide some context and relevant parts, but is not a duplicate.)


Tikzpicture Foreach loop curves not showing up and error in color change

In some stackexchange questions, some people posted code in making the code plot the curves iteratively. However, when I try mine, the orange curves do not show up. Here is the code:  \begin{figure}[H]\centering             \begin{tikzpicture}                 \def\Bound{(5*sqrt(2) - sqrt(150 - 100*sqrt(2)))/2}                 %\def\radius{4}                 %\def\startPt{acos( (5+\radius + sqrt((5+\radius)^2 - 50) )/(2*\radius) - 1 )}                 %\def\endPt{acos( (5+\radius - sqrt((5+\radius)^2 - 50) )/(2*\radius) - 1 )}                 \begin{axis}[                     %xmin=0,xmax=4500,                     %ymin=0,ymax=0.3,                     xmin=0,xmax=10,                     ymin=-5,ymax=5,                     axis lines=center,                     axis line style=->, xlabel = {$t$}, ylabel={$V\left(t\right)$},                     axis equal,                     legend cell align = {left},                     every axis y label/.style={at={(0,1)},anchor=south},                     every axis x label/.style={at={(1,0)},anchor=west},                     title= {Invariant Set Plots},                   domain=0:15,samples=300,legend pos=outer north east]                     \addplot [color = blue, thick, domain = -10:10] {x - 5};                     %\addlegendentry{$V_0 = 0.01$};                     \addplot [color = red, thick, domain = 0:2*pi] ({\Bound + \Bound*cos(deg(x))}, {\Bound*sin(deg(x))});                      \foreach \y in {3, 3.5,4,4.5}{                         \def\radius{\y};                         \def\startPt{acos( (5+\radius + sqrt((5+\radius)^2 - 50) )/(2*\radius) - 1 )};                         \def\endPt{acos( (5+\radius - sqrt((5+\radius)^2 - 50) )/(2*\radius) - 1 )};                         %\pgfmathtruncatemacro{\tmp}{100 - \x*20};                         \addplot[color = orange, thick, domain = \startPt:360-\endPt] ({\radius + \radius*cos(x)}, {\radius*sin(x)});                     }                     %\addplot [color = orange, thick, domain = \startPt:360-\endPt] ({\radius + \radius*cos(x)}, {\radius*sin(x)});                     %\addplot [color = orange, thick, domain = 0:3]{\startPt/360};                     %\addlegendentry{$V_0 = 0.5$};                     %\addplot [color = brown, thick, domain = 0:15] {1/(1-(1-1)*exp(-2*x))};                     %\addlegendentry{$V_0 = 1$};                     %\addplot [color = orange, thick, domain = 0:15] {1.5/(1.5-(1.5-1)*exp(-2*x))};                     %\addlegendentry{$V_0 = 1.5$};                     %\addplot [color = purple, thick, domain = 0:15] {2/(2-(2-1)*exp(-2*x))};                     %\addlegendentry{$V_0 = 2$};                 \end{axis}             \end{tikzpicture}              \caption{Optimal Curves.}         \end{figure}   In fact, when I try change the color over each iteration as shown in the code below:      \foreach \x/\y in {0/3, 0.5/3.5, 1/4, 1.5/4.5}{                         \def\radius{\y};                         \def\startPt{acos( (5+\radius + sqrt((5+\radius)^2 - 50) )/(2*\radius) - 1 )};                         \def\endPt{acos( (5+\radius - sqrt((5+\radius)^2 - 50) )/(2*\radius) - 1 )};                         \pgfmathtruncatemacro{\tmp}{100 - \x*20};                         \addplot[color = orange!\tmp!yellow, thick, domain = \startPt:360-\endPt] ({\radius + \radius*cos(x)}, {\radius*sin(x)});                     }   I even get an error message saying that it's an Undefined control sequence at the \end{axis} command.  Does anybody know what is going on with the code?


Resource recommendations on Renormalization Group Flow

I've read two notes on RG flow:       I've also read RG flow on Peskin's. I think have to say I still don't have a clear image of the meaning of RG flow since the notes I've read so far discuss the topic with a particular example mostly with real scalar field. In addition, I read in a paper that there are several different types of RG flow and it makes me even more confused.     Can you suggest me a good reference on RG flow based on more mathematical language? I need to grasp a precise general overview!


Cutting a pie into n equal area pieces with the minimum distance of cuts.

Suppose we are to cut a unit circle into n equal area pieces. We can cut curves if we wish. What is the minimum distance we must cut? What strategy minimises this distance? Note: The shape of the pieces doesn't matter, nor does the number of cuts.  When n=2, clearly we simply cut a diameter, yielding a distance cut (C) of 2.  When n=3 and n=4, it seems that the optimal cutting method is simply to make equally spaced n radial cuts.  However, there must be a different strategy for some higher n. For instance, with n=10, it would be better to cut a second circle, of area Pi/2, and circumference Pi*sqrt 2, and 5 radial cuts; rather than 10 radial cuts.  So, what is the relationship between n and the distance, and what is the general optimal strategy?


What is the reason for Moon and satellite in free fall condition?

I am a high school student. I read in my book that moon and satellite are in free fall condition with Earth. I asked my teachers about this, but I'm not able to understand. Can anyone explain to me why this happens?   Edit- if something is orbiting around the planet is he also in a free fall condition,.


How do I make an HTML text box show a hint when empty?

I want the search box on my web page to display the word "Search" in gray italics. When the box receives focus, it should look just like an empty text box. If there is already text in it, it should display the text normally (black, non-italics). This will help me avoid clutter by removing the label.  BTW, this is an on-page  search, so it has no button.


How can I check whether a person who puts DSc after their name is in fact entitled to do so?  Is it possible to find out where this person was allegedly confirmed as a DSc?


How do you configure an OpenFileDialog to select folders?

In VS .NET, when you are selecting a folder for a project, a dialog that looks like an OpenFileDialog or SaveFileDialog is displayed, but is set up to accept only folders.  Ever since I've seen this I've wanted to know how it's done.  I am aware of the FolderBrowserDialog, but I've never really liked that dialog.  It starts too small and doesn't let me take advantage of being able to type a path.  I'm almost certain by now there's not a way to do this from .NET, but I'm just as curious how you do it from unmanaged code as well.  Short of completely reimplementing the dialog from scratch, how do you modify the dialog to have this behavior?  I'd also like to restate that I am aware of the FolderBrowserDialog but sometimes I don't like to use it, in addition to being genuinely curious how to configure a dialog in this manner.  Telling me to just use the FolderBrowserDialog helps me maintain a consistent UI experience but doesn't satisfy my curiosity so it won't count as an answer.  It's not a Vista-specific thing either; I've been seeing this dialog since VS .NET 2003, so it is doable in Win2k and WinXP.  This is less of a "I want to know the proper way to do this" question and more of a "I have been curious about this since I first wanted to do it in VS 2003" question.  I understand that Vista's file dialog has an option to do this, but it's been working in XP so I know they did something to get it to work.  Vista-specific answers are not answers, because Vista doesn't exist in the question context.  Update: I'm accepting Scott Wisniewski's answer because it comes with a working sample, but I think Serge deserves credit for pointing to the dialog customization (which is admittedly nasty from .NET but it does work) and Mark Ransom for figuring out that MS probably rolled a custom dialog for this task.


Has the USA started allowing tourists from the United Arab Emirates (Dubai)? I want to visit the USA in the beginning of November. I heard they are not allowing tourists only from certain countries in Europe/UK. But what about other parts of the world such as Dubai?


Disc brakes on leader doberman which has no tabs and adaptors

I have a leader doberman with a front disc brake that I want to install on the rear. I know that it hasn't a rear disc brake tab, but I have found an adaptor for the caliper ()    Now I don't know how to mount the rotor, but I have found something to mount it ().    But is this compatible with my rear hub? What can I do? Only to stich it with glue or there is a solution?   I have the classic Shimano gear levers. Will I have to change the shifters to install hydro disc brakes?


Why do I have the same validation accuracy for every epoch?

I developed a CNN for ECG arrhythmia classification and when I train the model I obtain the same validation accuracy for all of the 50 epoch. Can you please tell me what is wrong? I tried to modify the parameters, also the structure, but the validation accuracy is unchanged (80.1%). The ECG signals fed into the network are ECG heartbeats composed of 1x300 vectors (300 sample points signals). height = 1; width = 300; channels = 1; Xtrain = reshape(Xtrain,[height, width, channels, length(Xtrain)]); Xvalidation=reshape(Xvalidation,[height, width, channels, length(Xvalidation)]); Xtest = reshape(Xtest,[height, width, channels, length(Xtest)]); Ytrain=categorical(Ytrain); Yvalidation=categorical(Yvalidation); Ytest=categorical(Ytest); Layers=[ imageInputLayer([height,width,channels]); %'DataAugmentation', 'none'); %'Normalization', 'none');  convolution2dLayer([1 3], 256,'stride',[1 1], 'padding','same');  %Filter window size = [1 5], No of filters = 64, stride = [1 1];  convolution2dLayer([1 3], 256,'stride',[1 1], 'padding','same');   reluLayer(); dropoutLayer(); maxPooling2dLayer([1 2],'stride',[1 2]); %PoolSize = [1 2], Stride = [1 1]   convolution2dLayer([1 3], 128,'stride',[1 1], 'padding','same');   reluLayer();  convolution2dLayer([1 3], 128,'stride',[1 1], 'padding','same');   reluLayer();  convolution2dLayer([1 3], 64,'stride',[1 1], 'padding','same');   reluLayer(); dropoutLayer(); maxPooling2dLayer([1 2],'stride',[1 2]); fullyConnectedLayer(256);  dropoutLayer(); fullyConnectedLayer(128);  fullyConnectedLayer(5); %Reduce to five output classes softmaxLayer(); classificationLayer(); ]; options = trainingOptions('sgdm','InitialLearnRate',0.001,'MaxEpochs',50, ... 'LearnRateSchedule','piecewise', ... 'LearnRateDropFactor',0.1, ... 'LearnRateDropPeriod', 3,... 'L2Regularizatio',1.0000e-04, ... 'MiniBatchSize', 60,... 'ValidationData',{Xvalidation, Yvalidation},... 'Plots','training-progress'); convnet = trainNetwork(Xtrain,Ytrain,Layers,options);


Indentation of examples with Linguex and Brill typeface

The text of examples is too close to the example number with example numbers having three or more digits. The problem relates to the use of the Brill font, as it disappears with other fonts.     Here's a MWE:  \documentclass{memoir} \usepackage{mathastext} \usepackage[no-math]{fontspec} \setmainfont{Brill}  \usepackage{linguex}  \begin{document}   \ex. [$_S$ [$_{NP}$ Bartoli] [$_{VP}$ zoent Pavarotti]]  \setcounter{ExNo}{49}  \ex. [$_S$ [$_{NP}$ Bartoli] [$_{VP}$ zoent Pavarotti]]  \ex. [$_S$ [$_{NP}$ Bartoli] [$_{VP}$ zoent Pavarotti]]  \setcounter{ExNo}{99}  \ex. [$_S$ [$_{NP}$ Bartoli] [$_{VP}$ zoent Pavarotti]]  \end{document}


Calculating EVI from Sentinel 2 imagery gives difference in results between ArcMap & QGIS?

Though EVI coefficients have not been developed for Sentinel 2 imagery, I am using the same coefficients used for MODIS to calculate EVI for Sentinel imagery.  I know that Sentinel 2 imagery is TOA reflectance and has a scaling factor of 10000. Hence, can I use the following formula to calculate EVI  (2.5* (NIR/10000-red/10000))/(NIR/10000+(6*red/10000)- (7.5*blue/10000)+1)   I did the above calculation in Arcmap and QGIS but got completely different results- QGIS gave me a plausible range of -0.048 to 0.3915,while ArcMap included a range of -31.68 to 45.17. The mean and std in ArcMap are 0.1718 and 0.0887 leading me to believe that these extreme values are a few pixels only. How do I clip these extra pixels of in ArcMap?


Example of bounded f:[0,1]->R which has primitive but not Riemann-integrability in closed interval?

This must be a function which is antiderivative but it has no Riemann-integral. These conditions must be fulfilled in closed interval from 0 to 1.


Today I picked the Electorate badge, but it is still not visible on my account. Why is it too late arrive? When will it show on my profile? I voted on 600 questions and 25% or more of total votes are on questions.


I have a project I am working on that involves a view screen I made. At one point, just to tinker with it, I was trying to get a video rendered on that view screen. All that ended up happening was Blender rendered only that video and not the whole project. I set it up with the movie clip editor section. I decided it wasn't going to work for what I wanted to do anyway so I deleted that video and just put an image on the view screen. I am trying to get Blender to render the project again but it still is only rendering images from the deleted video. I deleted the video from the movie clip editor but it is still being rendered. Its got to be a simple setting I am overlooking, or at least I hope so. How do I get Blender to go back to rendering the whole project I am working on? If more info is needed, please just ask and I will provide whatever is needed.


How can I create a block cipher of a reduced size given a fixed length block cipher?

I've been reading papers on variable sized block cipher constructions based on fixed-length block ciphers, and they tend to focus on increasing the block size. They either gloss over or speak too generally about decreasing the block size. (Or I'm just not getting it, which is possible)     While these are certainly helpful, I also need a way to encrypt a size much smaller than the usual block ciphers. For example, a credit card has 16 digits, which can be represented in 54 bits. To encrypt a credit card number to another one would require a 54-bit block cipher. (The 54-bits could be brought even lower if you consider that the first and last digits are not random)  Is there a way to do this in such a way that the security isn't brought below the chance of simply guessing the plaintext?


Null object reference when calling a constructed textview

I created a text view dynamically , but the problem is that when I want to set the text size of this text view on a button click, I get:  error: null object reference.  the code:  //in Main class  TextView textview;   //creating the text view on button click Button mbutton1=(Button)findViewById(R.id.button1); mbutton1.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View view){  textview=new TextView(this);  //adding the view to the relativelayout RelativeLayout.LayoutParams params=new RelativeLayout.LayoutParams (ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT ); textview.setLayoutParams(params);  //making object for Relativelayout and add the view to activity RelativeLayout relativel=(RelativeLayout)findViewById(R.id.relativelayout); relative1.addView(textview); } });  //now here is the button which must set the size of this text view  Button mbutton2=(Button)findViewById(R.id.button2); mbutton2.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View view){ textview.setsize(20);  } }); //And the error is when I click button 2 it says null object reference.   Edit: This question was closed as duplicate of another but in the other question the answers were why (null object reference)error happens , I know the causes for the problem what I need is an answer on how to set a value for a non existing object in an activity.


How do I connect a PS3 Controller with Xperia P?


I getting an error report of:   Error report - SQL Error: ORA-02270: no matching unique or primary key for this column-list 02270. 00000 -  "no matching unique or primary key for this column-list" *Cause:    A REFERENCES clause in a CREATE/ALTER TABLE statement            gives a column-list for which there is no matching unique or primary            key constraint in the referenced table. *Action:   Find the correct column names using the ALL_CONS_COLUMNS            catalog view    Can I know why?  parent table      CREATE TABLE STUDENTINFO     (       Student_ID VARCHAR2 (10) PRIMARY KEY,       Full_Name VARCHAR2 (50) NOT NULL,       Contact_Number NUMBER (15)NOT NULL,       Address VARCHAR2 (50) NOT NULL,       Nationality VARCHAR2 (15) NOT NULL,       IC_PassportNo VARCHAR2 (15) NOT NULL,       Programme VARCHAR (75) NOT NULL,       Email_Address VARCHAR2 (50) NOT NULL REFERENCES                    USERNAMEPASSWORD(Username),       Parents_Number NUMBER (15)NOT NULL,       Fingerprint_Template clob     );   child table      create table bit_2015_sep_cit4114_fyp_G_     (        Student_ID VARCHAR2 (10) PRIMARY KEY REFERENCES STUDENTINFO(Student_ID),       Full_Name VARCHAR2 (50) NOT NULL REFERENCES STUDENTINFO(Full_Name),       Nationality VARCHAR2 (15) NOT NULL REFERENCES STUDENTINFO(Nationality),       Fingerprint_Template CLOB NOT NULL REFERENCES        STUDENTINFO(Fingerprint_Template),      "23/10/2015" VARCHAR2 (15) not null,     );   I keep nationality and fingerprint as duplicate because it will be time consuming in verifying based on all information stored in studentinfo, therefore by breaking into individual class will be easier and faster. like for the table STUDENTINFO consist 1 million record, in table bit_2015_sep_cit4114_fyp_G_ will only have 40 records. I keep the nationality column because I have 1 more column in my table structure which is visa renewal which calculated based on the value of nationality in the table.


Fix for word of power quest bug at Arcwind Point

When I picked up the word of power at Arcwind Point, the quest didn't get removed from my quest log. If I select it, the arrow still points to the wall even though there is no word to collect anymore. The monks at High Hrothgar won't give me a new word power quest since they don't realize that I finished this one.  I can see in the Unofficial Elder Scrolls pages that this is a known issue.   My question is now, is there anything I can do about it? I don't want to reload a previous save since I have done much since it happened. I didn't realize until hours afterwards what had happened.   Note: I am on Xbox 360 so the Unofficial Dawnguard Patch is not an option.


How do I use the /tellraw command in minecraft 1.10

I want to make a map but the /tellraw command won't work in Minecraft 1.10, not 1.9 or 1.8 just 1.10 it used to work perfectly in 1.8 as:  /tellraw @p {text:"what ever you want",color:red,bold:true,underlined:true,clickEvent:{action:open_url,value:"a url"}}   How can I fix this?


Do 10k users get to read deleted comments?

Do 10k (and moderator) users have the ability to read deleted comments (are comments deleted forever, or never really deleted like questions and answers)?


The limit superior of $|\sum_{i=1}^n x_i^k|^{1/k}$ where $x_i\in\mathbb{C}$

I am thinking about the following questions:  $A$ is a complex $n\times n$ matrix, $\rho(A)$ means the spectral radius of $A$, $\operatorname{tr}(A)$ means the trace of $A$, then prove: $$ \varlimsup_{k\to\infty} \big( |\operatorname{tr}(A^k)|^{1/k} \big) = \rho(A). $$  It is clearly equivalent to $$ \varlimsup_{k\to\infty} \left| \sum_{i=1}^n x_i^k \right|^{1/k} = \max_{1\le i\le n} |x_i|, \quad x_i\in\mathbb{C}, i=1,\cdots,n. $$ When every $x_i\in\mathbb{R}$, it is easy. But when all of $x_i$ are complex, I can only obtain $$ \varlimsup_{k\to\infty} \left| \sum_{i=1}^n x_i^k \right|^{1/k} \le \max_{1\le i\le n} |x_i|. $$ Any hint?


The  suggests that after creating a chat room I should be able to invite users to chat from the room menu. I created  to discuss a problem but the room menu has no such invite function.  suggest I should only be able to invite users who are already in a chat. Update: While testing  we discovered there are three separate systems, which further adds to the confusion. Can you please correct the current documentation, update it to show how chat currently works, and in particular address these points of confusion?


Attempt to invoke virtual method '' on a null object reference

I'm getting this error "Attempt to invoke virtual method 'java.lang.String eecs1022.caps.Game.qa()' on a null object reference"  I just want to know why im getting this error and how I can work around it.  The game object is returns a string but for some reason it says its a null object. Here is my main class and my game class.  MAIN:  private Game game; private String question = ""; private String answer = ""; private int score = 1; private int qNum = 1;   @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     ask();     }   public void ask(){      String apple = game.qa();     int indexanswer = apple.indexOf("\n");     answer = apple.substring(indexanswer);     question = apple.substring(0,indexanswer);      ((TextView)findViewById(R.id.question)).setText(question);  }  public void onDone (View v){      if (qNum == 10){         finish();     }      String answerinput = ((EditText)findViewById(R.id.answer)).toString();      if (answer.equalsIgnoreCase(answerinput)){         score++;     }      String oldlog = ((TextView)findViewById(R.id.log)).toString();     String a = oldlog + "\n" + "Q# " + qNum + ": " + question + "\n" + "Your answer" + answerinput.toUpperCase() + "\n" + "Correct Answer: " + answer + "\n";     ((TextView)findViewById(R.id.log)).setText(a);      qNum++;     String orange = "SCORE = " + score;     String banana = "Q# " + qNum;      ((TextView)findViewById(R.id.score)).setText(orange);     ((TextView)findViewById(R.id.qNum)).setText(banana);      ask(); }   }  GAME:           public class Game {  public String capitalanswer = ""; public String countryanswer = "";  private CountryDB db;  public Game(){     this.db = new CountryDB(); }  public String qa(){      List<String> countries = db.getCapitals();     int n = countries.size();     int index = (int)( n * Math.random());     String c = countries.get(index);     capitalanswer = c;     System.out.println(capitalanswer);      Map<String, Country> data = db.getData();     Country ref = data.get(c);     countryanswer = ref.toString();     System.out.println(countryanswer);      if (Math.random() < 0.5){         return "What country has the capital " + ref.getCapital() + " ?" + "\n" + ref.getName();     }else{         return "What is the capital of " + ref.getName() + " ?" + "\n" + ref.getCapital();     }  }   }  Any help is appreciated!


Too many commas in the social network share text

The bug appears, with my account, in every post that haven't any answer yet. At the bottom just above the "Your Answer" section, I always see:     Know someone who can answer? Share a link to this question via email,   , , or .   In my mind, there should be a link to share to Twitter, Facebook, or other social networks, but I'm on any of these.