In QGIS 3.10.4 on Mac, I have two multipoint shapefiles: one is "Start" points, and the other is "To" points. Each layer has "x" and "y" coordinate columns in the attribute table. "Start" points only have "location_name" (string) as IDs, and "To" points have ID numbers as IDs. I also merged the two layers, so I have a layer that has both sets of points if needed. My goal is to draw lines between each "start" point and each "to" point. Many plugins in other answers cannot be found now. I'm wondering how can I do so? The points look like the picture below, red dots are Start points, and blue ones are Tos.

How do I create a vector layer with a network of line segments drawn between every point in another vector layer? Basically, I am trying to create something similar to a hub/spoke network, except that instead of having a single hub and the other points are destinations, I would like every point to be treated as a hub with a direct connection to every other point. I have managed to get the hub lines from one point to every other using the MMQGIS plugin "Hub Lines" module, but it seems that I would need to re-run it for each individual point. Is there a way to just do it all in one go in QGIS? It may be worth noting that I don't need to know the distances between the points; I'm looking for the azimuths.


I downloaded this very awesome set of iOS7 GUI components to use for building mockups for apps, found here: .  I'm working in Illustrator but the file is a PSD.  I'm running both Ps and Ai simultaneously, and when I drag a component from the PSD into my Ai file, the transparency becomes white.  To be clear, I am literally dragging and dropping from Ps into Ai using the Move Tool which generally works.  What am I doing wrong here? Thank you!

I often run into this issue. I'm creating a file in Photoshop with masked layers etc. I want to make the final output available for some mock-ups in Illustrator, so I rasterize the layers and marquee select the entire area, copy and move to Illustrator.  Pasting the area in Illustrator flattens all transparencies, which is quite annoying. I'm left with my object and a flat white background.  Is there a reason for this?


From Earth we say that the age of the universe is 14.5 billion years ago because that is how far we are able to see. But since we are probably not the center of the universe, wouldn't some one many billion light years away from us feel that the age of the universe is different ?  If so, how is it possible that the age of the universe varies by distance ?   This question came to my mind whilst watching tis video  [about the 8:30 mark till 12 mins]

Given the definition of unix timestamp as the number of seconds elapsed since January 1st, 1970 as GMT+0, without leap seconds, is it possible to create a universal clock that will generate the correct timestamp?  Is the current definition of a second      the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom.[1] In 1997 CIPM added that the periods would be defined for a caesium atom at rest, and approaching the theoretical temperature of absolute zero (0 K), and in 1999, it included corrections from ambient radiation.[1] Absolute zero implies no movement, and therefore zero external radiation effects (i.e., zero local electric and magnetic fields).   sufficient for this?


I have an object literal, a:  a = {foo: 'foo'};   And I want to get b, the combination of a and {bar: 'bar'}:  b = {foo: 'foo', bar: 'bar'};   How can I do with without writing out all of the properties of a? i.e:  b = a + {bar: 'bar'};   And no, I do not want to have a be a property itself of b, as shown here:  b = {a: a, bar: 'bar'};

I need to be able to merge two (very simple) JavaScript objects at runtime.  For example I'd like to:  var obj1 = { food: 'pizza', car: 'ford' } var obj2 = { animal: 'dog' }  obj1.merge(obj2);  //obj1 now has three properties: food, car, and animal   Does anyone have a script for this or know of a built in way to do this?  I do not need recursion, and I do not need to merge functions, just methods on flat objects.


It is inconceivable that this is proving to be so difficult but I'm trying to use rsync to copy only files matching a specific pattern. Specifically, copy files in all subdirectories matching "*000.csv"  You would think that the following  rsync -avrP --include='*000.csv' host:'~/data/' .   would do the trick. Instead this targets all files in all subdirectories (?!).  suggests you can only "include" things that have been excluded first. Okay, so then why do these:  rsync -avrP --exclude='*' --include='*000.csv' host:'~/data/' .  rsync -avrP --filter='-! */' --include='*000.csv' host:'~/data/' .   both target no files at all. Please help. Thank you.

I am trying to create a directory that will house all and only my PDFs compiled from LaTeX. I like keeping each project in a separate folder, all housed in a big folder called LaTeX. So I tried running:  rsync -avn *.pdf ~/LaTeX/ ~/Output/   which should find all the pdfs in ~/LaTeX/ and transfer them to the output folder. This doesn't work. It tells me it's found no matches for "*.pdf". If I leave out this filter, the command lists all the files in all the project folders under LaTeX. So it's a problem with the *.pdf filter. I tried replacing ~/ with the full path to my home directory, but that didn't have an effect.  I'm, using zsh. I tried doing the same thing in bash and even with the filter that listed every single file in every subdirectory... What's going on here?  Why isn't rsync understanding my pdf only filter?    OK. So update: No I'm trying  rsync -avn --include="*/" --include="*.pdf" LaTeX/ Output/   And this gives me the whole file list. I guess because everything matches the first pattern...


Why are plants not affected by animal viruses such as retroviruses? What prevents them from being infected?

Coronavirus, HIV, 1918 Flu, etc. They all come from animals. Do any infectious diseases (in humans) come from plants? More specifically, are there viruses that infect plants that can mutate to infect humans?


I've been dumb and downloaded the malware from coolrom that inputs some sort of """search engine""" in firefox. I'm trying everything to clean that but without success. Someone knows how should I do it?

Switched my sister to Ubuntu because I got tired of re-installing the other OS every 6 months. Now she managed to get some malware in her Firefox on Ubuntu.  Without access to the computer (or when I get it next week), where should I look, what questions can I ask, what could I tell a computer novice to try over the phone?  Symptoms: While surfing some recipe site she had an ad-window pop up with no window controls. She rebooted the computer and when she re-started Firefox it came back, full screen, no controls, on top.    I told her to just use -F2 and xkill to get rid of it, which it did but stopped Firefox completely. On re-start it was back, I told her to hit F11 which did take it back to a large screen, but not full-screen, so she could see that there was a normal browser window running underneath. She topped the normal window but the only other thing I had time to check was plug-ins, which there wasn't anything that sounded suspicious. I'm looking for ideas of what to try over the phone, or where to start next week.    I'm comfortable with the command line, and using about:config if that makes any difference in the answer.


There are two ways to prove that every $k$-vector space $V$ has a basis. First, choose a linearly independent set of $V$, use Zorn lemma to prove that it must be contained by a maximal linearly independent set, then prove that the maximal linearly independent set is a basis. Second, we can choose a generating set $B$ of $V$, prove that there is a minimal generating set which is contained in $B$, and then prove that every minimal generating set is a basis. However, I don't know how to prove that every generating set of a vector space has a minimal generating set, could someone help me with that? Thank you!

Let $S$ be an infinite generating set of a finite dimensional vector space , then how do we prove that there is a subset of $S$ which is a basis of the vector space ?  Please help


i have to insert till 30000 record from delphi into MsAccess database using DAO. with normal insert into this take a lot of time > 10 minutes... I've read there is a procedure to insert directly from txt file (using adoCommand) but i don't understand how to made it.  Someone can help me?  Thank you for your help

I need to insert 800000 records into an MS Access table. I am using Delphi 2007 and the TAdoXxxx components. The table contains some integer fields, one float field and one text field with only one character. There is a primary key on one of the integer fields (which is not autoinc) and two indexes on another integer and the float field.  Inserting the data using AdoTable.AppendRecord(...) takes > 10 Minutes which is not acceptable since this is done every time the user starts using a new database with the program. I cannot prefill the table because the data comes from another database (which is not accessible through ADO).  I managed to get down to around 1 minute by writing the records to a tab separated text file and using a tAdoCommand object to execute  insert into table (...) select * from [filename.txt] in "c:\somedir" "Text;HDR=Yes"   But I don't like the overhead of this.  There must be a better way, I think.  EDIT:  Some additional information:   MS Access was chosen because it does not need any additional installation on the target machine(s) and the whole database is contained in one file which can be easily copied. This is a single user application. The data will be inserted only once and will not change for the lifetime of the database. Though, the table contains one additional field that is used as a flag to indicate that the corresponding record in another database has been processed by the user. One minute is acceptable (up to 3 minutes would be too) and my solution works, but it seems too complicated to me, so I thought there should be an easier way to do this. Once the data has been inserted, the performance of the table is quite good. When I started planning/implementing the feature of the program working with the Access database the table was not required. It only became necessary later on, when another feature was requested by the customer. (Isn't that always the case?)   EDIT:  From all the answers I got so far, it seems that I already got the fastest method for inserting that much data into an Access table. Thanks to everybody, I appreciate your help.


I am trying to find specific input variables that I do append in my div based on the user requests.  Once the input variables are created I need to validate the content in the input tags before I can proceed. But I am not able to find those variables in jQuery..  Any help is appreciated.  $("#txtNoOfAccounts").on("focusout", function () {     var count = parseInt($("#txtNoOfAccounts").val());     $("#lblSuccess").text(' ');     $("#lblError").text(' ');     if (count.toString() != "NaN") {     $("#accountDiv").empty();      for (var i = 0; i < count; i++) {         $("#accountDiv").append(        "
" +            "
" + "<input type='text' name='AccountNo_" + i.toString() + "'" + " class='txtAccountNo' />
" +           "
" + "<input type='text' name='Suffix_" + i.toString() + "'" + " class='txtSuffix' />

")      }     } });   How do I find txtSuffix input variables.  I tried:  $('.txtSuffix').focusout(function (e) {     alert("Control Found"); });   I am not able to find those variables with jQuery.  Any help is appreciated.

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


Get two pieces of paper. In secret write the same number on both papers.  Transfer one paper to the Moon.  Look to the paper which is left at the Earth. Voila! We know what is on the Moon paper.  The papers are entangled in classical world, without any use of quantum mechanics. It is also clear that in this thought experiment we have no faster-than-light transfer of information.  So entanglement can be produced without quantum mechanics.  What is so special about quantum entanglement, that it is spoken about so much?

Consider that we have two balls, one white and one black, and two distant observers A and B with closed eyes. We give the first ball to the observer A and the second ball to the observer B. The observers don't know the exact color (state) of their balls, they know only the probability of having one or another color, until they look at them (measure). If the observer A looks at his ball he will see its color, which is white, so he immediately knows the color of the second ball. Lets call this “classical entanglement”.  My question is: What is the difference between this “classical entanglement” and the quantum entanglement, for example, of two entangled electrons with opposite spins states? Can this analogy be used to explain the quantum entanglement?


When using a hyphen directly next to a capital T the spacing (kerning) looks weird:  Input: Abc-Tuv  Output:    It seems as there is too much space between the hyphen and the T. I can reproduce this behavior in PdfLaTeX and XeLaTeX (even Word) using the default font.  Is this typographically correct? If it is not what would be correct? How can I achieve a consistent correct kerning throughout the document without specifying \kern manually on each occurrence?  Thanks for your answers.  Edit: Given that this question was marked as duplicate I realize that my formulation of the question was somewhat misleading. Maybe it would have been better to emphasize the typographical aspect of the question: Usually the automatic kerning works quite well (meaning that I never had to bother about it before). Why does the spacing look "wrong" in this special case? Am I mistaken and this is actually (typographically) correct? If it is not which value should I supply to \kern? Guessing a value and change it until it "feels" good? Is there a better way, so that the best value is chosen automatically?  I hope this clears things up, sorry for not being precise in the first place.

Is it possible to tell (La)TeX to adjust the kerning of a specific character combination?  For example, suppose I want !! to be typeset as !\kern 1.2pt!, just like ff is automatically turned into a ligature, or -- is converted to an en-dash.  I know I could create a command for this combination—I am asking for a way to just type !! and have it use my desired kerning.


I must prove that the ring of parts of set $X$, with the binary operations symmetric difference (as the sum) and the Intersection (as the product) is isomorphic to the ring formed by the functions of the form $f: X \rightarrow \mathbb{Z}_{2}$ under the sum and the usual product in $\mathbb{Z}_{2}$. I have been looking for functions that constitute a homomorphism and have not been able to find it, I appreciate your help.

I'm studying for an abstract algebra exam and one of the review questions was this:     Let $X$ be a set, and $\mathcal P(X)$ be the power set of $X$. Consider the operations $\Delta$ = symmetric difference (a.k.a. "XOR"), and $\bigcap$ = intersection.   a) Does $\Delta$ and $\bigcap$ make $P(X)$ into a ring?   b) If so, is it a ring with unity?   c) Is the ring commutative?   d) Is it a field?   For parts a) and b), I think it does form a ring with unity, but I'm not quite sure how to get started on proving it.   For part c), it is a commutative ring since $\mathcal P(X)$ is closed under symmetric difference and intersection, right?  Not even sure how to get started on d).  I'd really like to understand this question fully, so any kind of input would be tremendously helpful. Thank you!


I am trying to make my sections small caps. I have tried:  \documentclass{article}  \usepackage{lmodern}  \begin{document} \section*{\textsc{Test}} \end{document}   But this complains that no bold small caps font exists. How can I unbold the sections and as a bonus automatically make them small caps? I tried looking at titlesec but I found it quite confusing as I am a beginner.

How do I specify the fonts, and general font size, for the titles, chapters and sections in my document  Update:  I can see how my question is confusing.  I use \section and \chapter etc. to organise my document, and I would like to change the way the section and chapter titles are displayed.


I want to make some modifications to the gem https://github.com/opscode/knife-ec2 and use that locally with knife. I have the knife-ec2 gem installed locally, but I want to use the modified version for testing purposes. How can I do that?

If I download a .gem file to a folder in my computer, can I install it later using gem install?


I use Xubuntu. When I plug in my USB, I can simply mount and open it by clicking on its icon, but when I want to mount it from the command line, it needs root permission.   Why? And how can I mount my USB (the command line) without root permission? I can't put it in /etc/fstab, because it needs root permission.    Note: I don't want to mount an ISO file. My question was marked as duplicated but the target question had no valid answer. If you want to flag as duplicated, please first check the target question, and then add the duplicated flag. Thanks.

I have a file with an ext4 file system in it and want to mount it without using sudo every time (the script should run with user rights). The file I want to mount and the folder which I want to mount it too both are in my home directory which is encrypted, so I can't put the file location into /etc/fstab.  I tried fusermount but I always get error messages like "fusermount: extra arguments after the mountpoint".


Suppose we have $X_1, X_2,\dots X_n$ from some distribution $F$. We can then form the empirical distribution $F_n$ by saying:  $$F_n(x)=\frac{1}{n}\sum_{i=1}^n\mathbb{I}_{\{X_n\leq x\}}$$  I find it hard to visualize why does this distribution put weight $\frac{1}{n}$ to each observation $X_i$ since the graph is a step function. Any help is appreciated

I am trying to get a better understanding of kernel density estimation.  Using the definition from Wikipedia:   $  \hat{f_h}(x) = \frac{1}{n}\sum_{i=1}^n K_h (x - x_i) \quad = \frac{1}{nh} \sum_{i=1}^n K\Big(\frac{x-x_i}{h}\Big) $  Let's take $K()$ to be a rectangular function which gives $1$ if $x$ is between $-0.5$ and $0.5$ and $0$ otherwise, and $h$ (window size) to be 1.  I understand that the density is a convolution of two functions, but I am not sure I know how to define these two functions. One of them should (probably) be a function of the data which, for every point in R, tells us how many data points we have in that location (mostly $0$). And the other function should probably be some modification of the kernel function, combined with the window size. But I am not sure how to define it.   Any suggestions?  Bellow is an example R code which (I suspect) replicates the settings I defined above (with a mixture of two Gaussians and $n=100$), on which I hope to see a "proof" that the functions to be convoluted are as we suspect.  # example code: set.seed(2346639) x <- c(rnorm(50), rnorm(50,2)) plot(density(x, kernel='rectangular', width=1, n = 10**4)) rug(x)


I am having Samsung Galaxy S3 I9300XXELLA (O.s JB 4.1.2). Its update not available throught phone. So can I manually download JB 4.3 of I9300XXU. will it work or my phone with I9300XXELLA.

There are several reasons to be looking for a ROM:   Upgrading or downgrading your stock ROM Looking for firmware from a different region/language Flashing a custom ROM for different features, removing bloat, etc.   But where can one find ROMs in the first place?  What sites are likely to have the ROM I need?  ; please add to the wiki answer instead of posting separate answers.  See also:


I am using   <meta charset="utf-8">   still doesn't work. The fonts are broken. Any workaround without using html equivalent like "&Agrave;"?  Some guys are showing me the example of this  but it's not what I am looking for. I am not messing around database input or output. I just need to show plain text in html or php files but those french fonts are not showing properly. I can use their html equivalent but it is very tedious to edit all fonts one by one. I just wanted a simple workaround  Please check this image for better understanding. I wrote été but it is showing like the image below in Firefox browser. I am using it on wamp.

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I have a requirement to calculate the age of a member based on the Date of birth and Current date, and then classify that age into categories like Under 30, 31-40,41-50,51-60 and Above 60. Can some one help me with this query?

I want to see the data as follows  Member   Age  Category Test1    25    Under 30 Test2    55    51-60 Test3    67    Above 60   I have used the below query (from an answer to my ) to calculate the age from DOB and current date and then categorize each age under one name.   This query is creating separate columns, instead I want to see all the categories under one column so that I can group this category column  WITH AgeData as ( SELECT     Username,     Birthdate,     DATEDIFF(YEAR, birthdate, GETDATE()) AS AGE FROM @Table) SELECT     Username,     Birthdate,     Age,     CASE         WHEN AGE < 30 THEN 1         ELSE 0     END AS 'Under 30',     CASE         WHEN AGE BETWEEN 31 AND 40 THEN 1         ELSE 0     END AS '31 - 40',     CASE         WHEN AGE BETWEEN 41 AND 50 THEN 1         ELSE 0     END AS '41 - 50',     CASE         WHEN AGE > 50 THEN 1         ELSE 0     END AS 'Over 50' FROM AgeData


when we run a normal command we just type the name of it but why we use ./ instead of just typing its name when running the script?

While executing a C program, a.out, using the Ubuntu terminal, why do I always need to type ./ before a.out, instead of just writing a.out? Is there solution for this?


When a Stack Exchange site labeled beta closes, what happens to the questions that were posted on the site? Do they ever get archived somewhere, or are they all just gone?

I am answering questions on  - some of those answers are quite lengthy, including images and code (as are answers by others) and it would be a pity if they were just lost one day.   If the Beta site closed, I could envisage one or more of:   Moving some of the questions and answers to my own forum Moving them to the StackOverflow site (which already has a lot of questions/answers about Arduino) Move them to the , at which I am a moderator   Of course, in the case of my own answers there would be no issue of getting permission, and in the case of answers by other people this could follow discussion with the authors.  I would prefer to be able to access the markdown (question source) rather than having to redo the markdown when reposting.    So, my question is:   If a Beta site is closed down, is this after a warning period, so we have the ability to grab the markdown for answers we want to save (and any images)? Do we have the option to migrate them to other sites? (I currently don't have enough rep for that, perhaps I might have when and if the site closed). Even after the closing date, is there still a time period in which authors can migrate their questions/answers? Are some questions/answers migrated automatically (eg. if they have a good score)?   (My searches haven't revealed an exact answer to this).


A  is an informal term for:     A woman who associates with or marries a man chiefly for material gain   What would the gold digger's man be called? A mark? A sugar daddy?    Edit: I'm editing after my sugar daddy term has been reposted a couple of times, strangely with great success. I'd like a term for a man being targeted by the gold digger. So obviously as I listed sugar daddy in the question I felt that it was unsatisfactory; for example it works poorly here:     He's her sugar daddy.   While this is very accurate for a gold digger's man. You cannot take from this that he's being targeted, it even sounds like he's doing the targeting. This is closer:     He's her mark.   It's clear that he is being targeted. But unless the gold digger is also an assassin it seems a bit unclear what he's being targeted for.

It literally means to milk. It also means a dairy cow. It could be both a noun or verb.  v. To use someone for the money he/she can give you. n. Someone (a girlfriend, husband) that you milk for money.


I would like to know how to create one of those lenses for unity. I know how to program. but I don't know where to start. Are there certain libraries I should use or docs that I should read? Are there wiki pages that I can reference?  My google-fu has so far failed me.

I'd like to create a custom scope that searches and returns results from an online source for personal use.  Is this possible? And if so, how?


I have an old dell 630 with ubuntu 16.04 which upgraded to 18 which does not work well & won't update I want to revert to 16 or a linux version good with an older laptop

I just installed a new version of Ubuntu and I want to roll it back to the previous version.  How can I do that? Is that even possible?


Can someone help me giving a qualitative answer to this problem in General Relativity:  Imagine you are on earth with two perfectly synchronized clock's. If you hold one clock in your hand and throw the other one in the air and catch it back after a certain time interval, would the clock's still give the same time? Explain.  Thank you!

Can someone help me giving a qualitative answer to this problem in General Relativity:  Imagine you are on earth with two perfectly synchronized clock's. If you hold on in your hand but you throw the other one in the air and catch it after a certain time interval, would they still give the same time?  I think that the one in the air would run faster but I cannot explain why.  Thank you!


Are papers and articles really different in academic context or they are same words for the published manuscripts in conferences or journals?  The only thing comes to my mind is that may be an article is un-academic synonym of a paper, and it is not often used in academic context. Articles may be the texts which are published in a magazine; a paper is more academic, it is published in academic journals.  Could you please tell me what is the difference and whether there is any special usage of each word in papers published in a branch of science or in a country?

In the terminology for a peer-reviewed publication to be submitted to a reputable scientific journal, what are the differences and characteristic properties of the following?   draft manuscript preprint paper article   My own take on it would be that my text is a draft until I submit it to a journal, at which point it becomes a manuscript.  When the manuscript is accepted it becomes a preprint, and when it gets published it becomes a paper, which is synonymous to article.  Would that be an accurate summary?  Would anyone have corrections or additions?


Assume I have a very simple file with a matrix like  00011000 00022000 00011000 12100121 12100121 00011000 00022000 00011000   I want to import it to TikZ and transform it to a picture, where each cell in the matrix is interpreted as a small square with a color, defined by the content of the cell (e.g. 0 white, 1 gray, 2 black or so). I think that there is a quite simple solution for it. Probably I do not need a complete solution, some hints should be sufficient. Thanks in advance!

Can you create images like this:    when you have something like  0 = green (#54ff00) 1 = white (#ffffff) 2 = red   (#ff0000) 3 = blue  (#0048ff)  Image (Python list of integers defined above): [[2,0,0,0,0,0,0],  [0,3,0,0,0,0,0],  [0,3,2,1,1,0,0],  [0,3,2,2,2,1,1],  [0,3,2,0,0,1,0],  [0,0,0,0,0,1,0],  [0,0,0,0,0,1,0]]   with TikZ?  How far I got  The following MWE defines all colors, produces a grid of the correct size (though the size is determined by hand):  \documentclass[varwidth=true, border=2pt]{standalone} \usepackage{tikz} \usepackage{xcolor}  \begin{document}     \newcommand\n{7}     \definecolor{green}{HTML}{54FF00}     \definecolor{wite}{HTML}{FFFFFF}     \definecolor{red}{HTML}{FF0000}     \definecolor{blue}{HTML}{0048FF}     \begin{tikzpicture}         \foreach \x in {1,...,\n}{             \foreach \y in {1,...,\n}{                 \begin{scope}[shift={(\x,\y)}]                   \draw [fill=green] (0,0) rectangle (1,1);                 \end{scope}             }         }     \end{tikzpicture} \end{document}   Of course, I could simpy make a lot of adjusted                   \begin{scope}[shift={(\x,\y)}]                   \draw [fill=green] (0,0) rectangle (1,1);                 \end{scope}   but I've wondered if this can (with reasonable effort) be done in TikZ / LaTeX.  My problem is giving TikZ the color array. I don't have any idea how to do this. I only know two types of looks in TikZ:  \foreach \x in {0,1,2,3,4,5}{...} \foreach \number in {1,...,\n}{...}   I have never seen a nested over a 2D-array. All I have seen so far were 1D-Arrays of tuples (with fixed tuple size).


After I install the texlive 2016 (schema full), I got the error:  ! Missing number, treated as zero.   by compiling the code below with lualatex::  \documentclass[]{scrbook}  \title{Test}  \begin{document} \maketitle test \end{document}   There is no problem with pdflatex.  Hast my file an error, or must I search the error elsewhere?

\listfiles \documentclass[12pt]{standalone}      \usepackage{fontspec}  \begin{document}  test  \end{document}   creates  MiKTeX 2.9/tex/luatex/luaotfload/fontloader-2016-04-21.lua:353: attempt to call global 'getsubtype' (a nil value)  \endsa@boxit ... dvarwidth \color@endgroup \egroup  1.9 \end{document}  ?   Any ideas what this could be? I cannot imagein that I am wrong typsetting this example?


Device: Sony Xperia Z Ultra  Whenever baby is watching cartoons he likes to pick up the phone and his touch then stops the video or if he slides, it changes the app. How can I disable touch screen while the video is playing so even if he is playing with the screen the video keeps on going and nothing happens?  P.S: He probably thinks I have to burst these guys too, just like he does on bubble burst type games. He is 8 months.

Imagine that you want to do something, while the display in is action (not in sleep mode) and at the same time, you don't want to do anything else. This situation is like children lock, in which, all buttons fail to react, temporarily, to disable any kind of interaction by a child.  Is there a way to achieve this in Android? Do we have something like lock screen?


I'm working on an assignment that is teaching us to follow the factory patter. To do this I coded up some very basic classes and sub classes with only a few integer fields. After doing so I tried to see if I could successfully instantiate those sub-classes and get their fields. It worked fine when I passed a string that had been hard coded into the program, but when I tried to pass in user input via Scanner I got back a null pointer Exception. I cant figure out why, what would cause this? Here is my main method:  public static void main(String args[]) {     VehicleFactory vf = new VehicleFactory();     VehicleClass vc = null;     Scanner sc = new Scanner(System.in);     String type = null;       //this works     type = "car";     vc = vf.createVehicle(type);     System.out.println(vc.getEngineAmt());      //this throws and exception      //I even did a string cmp between sc.nextLine() and "car" for my sanity     //And the reurn was 0     vc = vf.createVehicle(sc.nextLine());     System.out.println(vc.getEngineAmt());      sc.close();  }     public class VehicleClass {  private int WheelAmt = 0; private int EngineAmt = 0;   public int getWheelAmt() {     return WheelAmt; } public void setWheelAmt(int wheelAmt) {     WheelAmt = wheelAmt; } public int getEngineAmt() {     return EngineAmt; } public void setEngineAmt(int engineAmt) {     EngineAmt = engineAmt; }     public class VehicleFactory {      public VehicleClass createVehicle(String type){          VehicleClass createdVehicle = null;          System.out.println(type);          if(type == "car")         {             createdVehicle = new Car();         }else if(type == "boat")         {             createdVehicle  = new Boat();         }else if(type == "plane"){             createdVehicle = new Plane();         }           return createdVehicle;     }  }

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


So, I've got about... 2 hours of Blender Experience as of right now. I did try searching for the answer to my issue in a few different places, but I'm not totally sure I know what to look for.   This is my object:    And this is what happens when I apply the Subdivision Surface Modifier:    As you can see the lid becomes significantly more round. I know I'm doing something wrong, but I'm not sure what. Should the lid be a separate object? Or is the issue something else entirely? I apologize if this is a really stupid question.

How can I use the subdivision surface modifier to create more high poly meshes without ruining sharp edges? For example this mesh  The sphere should be subdivided but the rim of the cylinder should stay the same because it is a sharp edge. This is the result of the subdevision  How can I get sharp edges to not be affected by the sub surf mod?


Riesz's lemma:  Let $Y$ and $Z$ be subspaces of a normed space $X$ and suppose $Y\neq Z$. Then for every $\theta\in (0,1)$ there is $z\in Z$ such that $\|z\|=1$ and $\|z-y\|\geq\theta$ for all $y$.  Using Riesz lemma prove that   A normed space is locally compact iff it is finite dimensional.  How to proceed ? Should I use the fact that    The unit ball is compact in a normed linear space iff the space is finite-dimensional.

I am studying functional analysis, and in the setting of normed spaces I have seen the theorem that states that the unit ball is compact iff the space is finite dimensional.  I also saw an exercise:     Let $X$ be finite dimensional, prove that for any non-empty and closed   $C$, $x\in C$ there exist $c\in C$ s.t $||x-c||=d(x,C)$.   The proof started with:     take $c\in C$ and consider  $$ D=\overline{B(x,||x-c||)}\cap C $$      $D$ is closed and bounded hence, since $X$ is finite dimensional, is   compact.   I would be glad if someone could help me with the following two questions:  1) It seems that the theorem I read about the compactness also extends to $X$ is finite dimensional iff $\{x,||x-x_{0}||\leq d\}$ is compact for any $x_{0}\in X,d\in\mathbb{R}^{+}$. is this correct ?  2) $C$ is closed, $\overline{B(x,||x-c||)}$ is also closed, hence so is the intersection. since $\overline{B(x,||x-c||)}$ is bounded then so is the intersection.  And so I get that $D$ is closed and bounded. Why can't I conclude that $D$ is compact without the assumption that $X$ is finite dimensional ?


I read that as long as I hold a stock for two business days, I will get a dividend? What if I make multiple trades for one stock. For example, if I buy 20 shares and sell 20 two days later, then I buy 30 shares and sell 30. How much in dividends will I get if it is $1/share?

For example, if the ex-dividend date is next Monday, and I buy the stock on next Monday, would I get the dividend? Or would the person who sold the stock to me get the dividend?


Suppose that we connect our flash USB drive to a MacBook, then eject this storage from Finder sidebar. Now I want to remount this storage without unplugging and replugging it into the computer, but the disk is no longer listed with diskutil list command.

I use a microSD card in my macbook air for additional storage, using a flush adapter (homemade, similar to the nifty minidrive).  To save battery when I'm not using it, I disabled auto-mount using /etc/fstab.  But sometimes, I accidentally eject it instead of unmounting (because that's what the finder gui does).   After it's ejected, the only way I know to remount is to take the card adapter out and put it back in. Since it's flush, I need a paperclip to take it out.  So I need a way to re-enable the card reader without having to re-insert.  In Windows, this is possible using the devcon command-line tool from microsoft, or going to device manager, disabling and enabling the card reader.  There has to be a way to do this, so please don't answer just saying it's not possible.  Thanks


I'm trying to prove it, but I can't find how.  If a divides b, and c divides d, then a*c divides b*d

I just need to check the reasoning in my proof is correct, I think it is valid although I'm not totally convinced because I can't follow the logic; does proving that $x$ is an integer prove that $ac|bd$?  Theorem: Let $a$, $b$, $c$, $d$ be integers. If $a|b$ and $c|d$, then $ac|bd$.  Proof: $aj=b$ and $ck=d$ for integers $j$, $k$. Then, $ac|bd$ implies $acx=ajck$ and thus $x=jk$ for some $x$. Since the product $jk$ is an integer, $x$ is an integer and thus $acx=ajck$ and thus $ac|bd$.


On Minecraft Bedrock Edition, I have just created a JSON file that creates a chest with random loot in it. The problem is that I don't know the command to get the chest that contains random loot. Here is what I did. I used  to create a loot table that gives you a certain amount of random items. I then saved this in a JSON file and put it in the following directory along with a manifest JSON file in order for Minecraft to recognise it.  The problem I am now having is that I don't know how to use the give command in Minecraft to give me a chest with random loot that uses the JSON file. The website I used to create the random loot table generator mentions this is the command you would use to get the chest with random loot from the JSON file loot table created (in Java Editon though): /give @p minecraft:chest 1 0 {BlockEntityTag:{LootTable:"mctools:chests/loot_table"}}  The problems I am having with this are that I don't know what directory I would need to put in to access the JSON file loot table, I am also not sure what other syntax would be needed because I know the idea of using minecraft:chest only works for Minecraft: Java Edition and for Minecraft: Bedrock Edition you would have to do something different. What I am asking is, what type of command do I need to use to give me a chest which uses the JSON file loot table?

This question was recently split into different questions for each workaround. See   meta posts for more information.   Can you use NBT tags in commands? I’ve tried commands that normally work in Java Edition like: give @s minecraft:planks 30 1 {display:{Lore:["Wooden planks"]}} give @s stone_pickaxe{Unbreakable:1b} give @s item_frame{EntityTag:{Invisible:1b}} summon villager ~ ~ ~ {Offers:{Recipes:[{buy:{id:"emerald",Count:5b},sell:{id:"diamond_sword"}}]}} summon tnt ~ ~ ~ {Fuse:20s}


So me and my friends are playing D&D 5E and my friend wants to cast magic missiles. Our DM says that he has to roll to cast the spell but my friend says he does not. So according to the rules of D&D 5E do you have to roll to cast magic missiles or any other spells? Do you need to roll for each missile to hit?

I understand to attack you need to make attack rolls, but does casting spells require any kind of test before they can be successfully cast or does the player just declare that the spell has been cast assuming they can. The starter rules don't seem to say.  Spells in questions are things like sleep or mage armor.


Compute the limit  $$\lim _{n \rightarrow \infty} \left(   \frac{1 + \frac{1}{2} + \frac{1}{3} + ... + \frac{1}{n}}{\ln n}   \right) ^{\ln n}$$  I know how to do  $$\lim _{n \rightarrow \infty} \frac{H_N}{\ln (n)} = 1$$ via L'Hopital's rule, but I'm not quite sure whether or not something similar is applicable here. I'm particularly concerned about the growth rates of the numerator and denominator in this case, but I haven't been able to make any meaningful progress. I would greatly appreciate assistance on this problem. Thank you.

I am trying to prove that   $\lim_{n\to\infty} (\frac{\sum^n_{k=1} \frac{1}{k}} { \ln(n) })^{ \ln(n) } = e^γ$ where $γ$ the Euler-Mascheroni constant. We know that that:  $\lim_{n\to\infty} \frac{\sum^n_{k=1} \frac{1}{k}}{ \ln(n) } = 1$  By approximating the sum with integrals $$ \ln(n+1)=\int_1^{n+1}\frac1x\mathrm dx\le\sum_{k=1}^n\frac1k\le 1+\int_1^n\frac1x\mathrm dx=1+\ln n $$ since $1/k$ is decreasing for $k\ge 1$. We have that $$ \frac{\ln(n+1)}{\ln n}=\frac{\ln n+\ln(1+\frac1n)}{\ln n}\to1 $$ as $n\to\infty$ and we obtain the result. But I can't calculate $\lim_{n\to\infty} (\frac{\sum^n_{k=1} \frac{1}{k}} { \ln(n) })^{ \ln(n) } = e^γ.$ Any help?


I've been searching the net in vain for a long time now and got nowhere, well until I found this site. Here is to hoping you can help me.   Back when I was in Secondary school (UK) in the early 1990's I borrowed from the school library a fantasy style book. Now sadly I cannot remember much about it other than it had your typical "assembled group" of young boy/hero, a warrior, a magician etc etc.  All I can remember of the book was when they fight the main villain/antagonist at the end the fight is desperate and the hero seems to think that his magician friend has been killed yet notices his hand twitching. Then a Demi-God appears who was summoned by the magician who was actually carving runes with his hand on the floor of the battle area.   I may be remembering wrong but I think the magician had a twin brother, the boy had/met a girl companion with a possible romantic link developing. They travel to the enemies castle/cave/domain and attempt to battle him and as said the magician summons a demi-god to defeat the evil antagonist. Any help would be greatly appreciated.  That is all I can remember unfortunately so any help, assistance or nudges in the direction of will be most appreciated.

This is a book I read as a child, so sometime in the 1980's  . It was actually a two part book series, both normal novel length. It was a swords and sorcery style setting.  Details are sketchy, but I'll give you what I can remember.  It centred around  a boy on a quest against some demon-like villain wizard type character. At some stage a girl was kidnapped and they were off to rescue her ( fairly generic stuff)  . I think the girl also had magic powers, healing I think.  This boy could control the weather or elements. He encounters a monk type character who ends up travelling with him and becomes a teacher of sorts. This monk is actually blind, but can still sense his surroundings, DareDevil style. ( I cannot remember if this was a magical ability or just something the monk had developed over time. ). I seem to remember this character had black, reptilian style eyes.  There may have been more people travelling with them I don't recall.  I recall the encounter with the main enemy took place on the top of a mountain, this mountain had the top taken off so was perfectly flat. ( I hope I'm not getting muddled with a different book with this detail)  The baddie know the boy could only control the elements if he was exposed to them, so ended up sealing the room he was fighting in so the boy had no contact with the outside. He won through by using a dagger or sword to make a crack in the floor through the protection, giving him enough of a connection with the outside to use his powers. I /think/ he died during this battle, and the girl they were rescuing brought him back to life. ( Or maybe she dies, and was brought back to life somehow)


How would make a "template" to find the $y_p$ of this equation?  $y''+9y = -6\sec 3t$  I'm not that good with trigonometric functions, but I'm pretty sure we have to do something to make it fit the $\,A \sin t + B \cos t\,$ template

I know how to solve it using Lagrange method of variation of constants, but is there easier way?


I've the code below       <img src="../../1021.png" alt class="img img-fluid">   </div>   i want to write some text and input field over this image without putting it as a background for some reasons , can that be done anyway ?

I want to overlay one image with another using CSS. An example of this is the first image (the background if you like) will be a thumbnail link of a product, with the link opening a lightbox / popup showing a larger version of the image.   On top of this linked image I would like an image of a magnifying glass, to show people that the image can be clicked to enlarge it (apparently this isn't obvious without the magnifying glass).


I have a basic question concerning calculus. I'm soon going to teach myself calculus and I wondered which textbook should I take :  Spivak's calculus or Lang's A first course in calculus  Any suggestions ? Thank you !

I want to start signal processing and I need a book that satisfies my mathematical requirements: I am in the third grade of high school and I don't know any useful thing about limit, differential, ...  Please help me.


I get that this topic has been discussed a lot, but other links haven't taken me anywhere on this problem. If someone would be kind and help, I'd really appreciate it.   I need to find out if the numbers square root gives us a perfect integer. And, then I need to count how many of them gave us that. I also have to count all the numbers, which I did that, but I can't seem to get around this one. The numbers are 64 bit (long).  To sum it up: I have to input a few numbers, then count how many numbers are. I did that. And then, find if any of these numbers, when in square root, give us a perfect integer. I hope I'm clear.  Any help? Thank you! :)

I'm looking for the fastest way to determine if a long value is a perfect square (i.e. its square root is another integer):    I've done it the easy way, by using the built-in  function, but I'm wondering if there is a way to do it faster by restricting yourself to integer-only domain. Maintaining a lookup table is impractical (since there are about 231.5 integers whose square is less than 263).   Here is the very simple and straightforward way I'm doing it now:  public final static boolean isPerfectSquare(long n) {   if (n < 0)     return false;    long tst = (long)(Math.sqrt(n) + 0.5);   return tst*tst == n; }   Note: I'm using this function in many  problems.  So no one else will ever have to maintain this code.  And this kind of micro-optimization could actually make a difference, since part of the challenge is to do every algorithm in less than a minute, and this function will need to be called millions of times in some problems.    I've tried the different solutions to the problem:   After exhaustive testing, I found that adding 0.5 to the result of Math.sqrt() is not necessary, at least not on my machine. The  was faster, but it gave incorrect results for n >= 410881.  However, as suggested by , we can use the FISR hack for n < 410881. Newton's method was a good bit slower than Math.sqrt().  This is probably because Math.sqrt() uses something similar to Newton's Method, but implemented in the hardware so it's much faster than in Java.  Also, Newton's Method still required use of doubles. A modified Newton's method, which used a few tricks so that only integer math was involved, required some hacks to avoid overflow (I want this function to work with all positive 64-bit signed integers), and it was still slower than Math.sqrt(). Binary chop was even slower.  This makes sense because the binary chop will on average require 16 passes to find the square root of a 64-bit number. According to John's tests, using or statements is faster in C++ than using a switch, but in Java and C# there appears to be no difference between or and switch. I also tried making a lookup table (as a private static array of 64 boolean values).  Then instead of either switch or or statement, I would just say if(lookup[(int)(n&0x3F)]) { test } else return false;.  To my surprise, this was (just slightly) slower. This is because .


Suppose $K(x,y)$ is a symmetric kernel and $K(x,.), K(.,y)$ are in $L^1(\Omega)$. Let $\phi\in L^{2}(\Omega)$, where $\Omega$ everywhere is a domain in $\mathbb{R}^n$. Can $\int K(x,y)\phi(y)dy$ belong to $L^2$?. In other words can an inequality of the type $||\int K(x,y)\phi(y)dy||_{2}\leq||K||_{L^1{\Omega\times\Omega}}||\phi||_{2}$ exist?.

Suppose $K(x,y)$ is a symmetric kernel. Let $\phi\in L^2(\Omega)$, where $\Omega$ everywhere is a domain in $R^n$.  Can $\int_{\Omega}K(x,y)\,\phi(y)\,dy$ belong to $L^2$?  In other words can an inequality of the type  $$ \left\|\int_{\Omega}K(x,y)\,\phi(y)\,dy\right\|_{2} \leq \|K\|_{L^1(\Omega\times\Omega)} \|\varphi\|_{2} $$ exist?


I was watching a google  techtalk with Donald Knuth and he mentions for every binary number $\overline{a_1a_2a_3\dots a_n}$ there exists $c_1<c_2<\dots <c_r=n$ so that:  $\overline{a_1a_2\dots a_{c_1}}+\overline{a_{c_1+1}a_{c_1+2}\dots a_{c_2}}+ \dots + \overline{a_{c_{r-1}+1}a_{c_{r-1}+2}\dots a_{c_r}}$ is a power of $2$.  Or in other words: every binary number can be separated into continuous pieces, which add up to a power of $2$. I have tried proving this for a bit, but I haven't gotten anywhere.

So given any binary string B:  $$b_1 b_2 \dots b_n$$ $$b_i \in \{0,1\}$$  It would seem it is always possible to make a partitioning of B:  $$ b_1 b_2 \dots b_{p_1}|b_{p_1 + 1}b_{p_1 + 2}\dots b_{p_2}|\dots|b_{p_m + 1}b_{p_m + 2}\dots b_n$$ $$= P_0 | P_1 |\dots|P_m$$  such that when $P_i$ is interpreted as the binary representation of an integer then:  $$\exists{k}:\sum_{i=0}^{m}P_i = 2^k$$  For example here is the first few:  1 = 1 10 = 2 1|1 = 2 100 = 4 1|01 = 2 11|1 = 4 1000 = 8 1|00|1 = 2 10|10 = 4 1|0|11 = 4 ...   Additional examples are here:   How can we prove this for all binary strings?


Some time ago I downloaded a bunch of steam games, that later I found out I couldn't play due to my shit graphics card. Now that I got a new one, I want to re download them, but they don't show up in my library, only some do. Also, I did I system restore to my pcs original settings and things. Is here any way I can list all of the games?

I bought a game on my dad's chrome book yesterday on steam and it told me to check my library for the games I bought, but they are not showing up. Do I have to buy them again? Or is there a way to download them, even though I didn't install them on the chrome book? Also, I was positive that I was on my account because I see them on the previous transactions thing, but they are not showing up.


Let $V$ be a finite dimensional vector space over the field $K$, with a non-degenerate scalar product. Let $W$ be a subspace. Show that $W^{\perp\perp}=W$.   I have no idea how to solve this one. Since I am self-studying I have no way to know if I get this right, that is the reason I ask for a resolution.  Questions:  Can someone provide me a resolution?  Thanks in advance!

I need to prove that if $V$ is a finite dimensional vector space over a field K with a non-degenerate inner-product and $W\subset V$ is a subspace of V, then: $$ (W^\bot)^\bot=W $$ Here is my approach:  If $\langle\cdot,\cdot\rangle$ is the non-degenerate inner product of $V$ and $B={w_1, ... , w_n}$ is a base of $V$ where ${w_1, ... , w_r}$ is a base of $W$ then I showed that  $$ \langle u,v\rangle=[u]^T_BA[v]_B $$ for a symmetric, invertible matrix $A\in\mathbb{R}^{n\times n}$. Then $W^\bot$ is the solution space of $A_rx=0$ where $A_r\in\mathbb{R}^{r\times n}$ is the matrix of the first $r$ lines of $A$. Is all this true?  I tried to exploit this but wasn't able to do so. How to proceed further?


Inside the block if __name__ == "__main__":  do I need to declare a variable as global in order to set its value? Or... is this block not a function and hence I don't need to do this? I guess the latter is true but I want to double-check and make sure I understand this better.

What exactly are the Python scoping rules?  If I have some code:  code1 class Foo:    code2    def spam.....       code3       for code4..:        code5        x()   Where is x found?  Some possible choices include the list below:   In the enclosing source file In the class namespace In the function definition In the for loop index variable Inside the for loop   Also there is the context during execution, when the function spam is passed somewhere else. And maybe  pass a bit differently?  There must be a simple reference or algorithm somewhere.  It's a confusing world for intermediate Python programmers.


Is there a way to add plain login/password credentials to my Stackoverflow account? In the My Logins page (/users/login-add) I can only add new Google and Facebook logins. There is no option to add plain login/password login however Stackoverflow allows to register new accounts without OpenID provider.

I no longer use the service that I originally used to register, and would like to change the service I use to log in, or at least add a second account.  Is this possible? How do I change my login provider or associate a backup method to log in?     For more information, see "" in the .


Say that I have this text      I need to think of something to write here.    I am an alumni of the college.    The blue cat is blue the red cat is red.    I want to be able to select everything if the word "student" (ignoring case) does NOT exist in the text. Therefore, I need something to go beyond the first line. I originally had something like   /(?:[^student]).*/    but it isn't working correctly. I am not sure what "flavor" of Regex I am using but it is with PHP and in the backend of a Drupal site.   Thank you!

I know it's possible to match a word and then reverse the matches using other tools (e.g. grep -v). However, is it possible to match lines that do not contain a specific word, e.g. hede, using a regular expression?   Input:  hoho hihi haha hede   Code:  grep "<Regex for 'doesn't contain hede'>" input   Desired output:  hoho hihi haha


I came across a meta-programming task that seemed like it must have an obvious and simple answer, but I could not find one.  I have a bunch of names wrapped in ():  (foo, bar, buzz, zap)   I want to quickly convert these names to a character vector:  ("foo", "bar", "buzz", "zap")   The fastest I could come up with is as follows:  as.character(quote(c(foo, bar, buzz, zap)))[-1] # "foo"  "bar"  "buzz" "zap"    I've got to imagine there's a cleaner solution.  EDIT  Possible duplicate, just with a very different title so it was hard to discover:

Anyone know if R has quote-like operators like Perl's qw() for generating character vectors?


I'm going to the US through SFO from Europe (Germany to France to US) and would like to bring loose teabags of British Yorkshire Tea. They are not packed like they were for sales, but rather in Tupperware because I buy them in big boxes. This might look a little suspicious I believe, and I don't want to get in trouble.

Today I was doing some research on food and drinks and realised that tea is not a very big thing in The U.S. and that all the "good" brands of tea are extremely overpriced or quite "unattractive".  So I thought I'd take a box (or two) with me to The U.S, but unfortunately the TSA might confiscate my tea and I may have to throw it away before I'm allowed to enter the country.  Would I be allowed to get on a plane from the UK and fly to The U.S. with tea? If not are there rules and regulations on shipping tea to The U.S. and would I be allowed to do it?  NOTE: when I say tea I mean Tea bags and Loose Leaf Tea.


Counting to 7 in binary looks like this:  0 1 10 11 100 101 110 111  The highest value is always to the left. But would it make more sense to to it like this? Is there a way that this was picked, or was it a random decision?  0 1 01 11 001 101 011 111

May somebody explain this in other words?   I know this is an akward question, but I really want to know the answer, it's just curiosity, I'm learning all that stuff of low level programming and learn binary system is one of the first steps to accomplish the objective.


In an experiment by Emilie du chatelet metal balls were dropped from a height on a clay bed only to find that the displacement of the clay material was proportional to the square of velocity of the ball and the depression of the clay bed was linearly proportional to the velocity of the ball. Does depression here mean depth ?  Also Emilie reasoned the above facts by proposing that depression was due to potential energy and displacement due to kinetic energy ?  In an earlier experiment Willem Gravesande showed that the depth was proortional to square of velocity so it makes no sense to say that by depression emilie meant depth . Or was willems experiment proved false ?  In another incident newton says that the material displaces by the ball will depend on its momentum and it will essentially displace the same amout of material as equal to its mass.  Are all these above views contradictory to one another ?  And can you please say which of the above views for depth and material displaced are corret and please back it with a mathametical explanation ?

William Gravesande in  1722 published an experiment in which brass balls were dropped from varying heights onto a soft clay surface. He found that a ball with twice the speed of another would leave an indentation four times as deep.   Some years later,  republished the experiment and proposed that each ball's kinetic energy - as indicated by the quantity of material displaced - was shown to be proportional to the square of the velocity and the deformation of the clay was found to be directly proportional to the height the balls were dropped from, equal to the initial potential energy.  So is kinetic energy inversely (squared) proportional to the quantity of clay displaced or is it proportional to the depth to which the ball will go ? Please provide an explanation not based on experimental data as most of 19th century physicists do. Also are any one of the effects mentioned above due to momentum of the ball ?   i am not asking about diameter and kinetic energy relationships , i am just askin about a derivation for the depth and displaced amount of material relationship with kinetic energy of some object.


In Redstone 3, which I still run on some machines, the pre-login screen, i.e. the screen on which you tap or click so you get the password box to pop-up is just an image. In Redstone 4, Miscrosoft added some "useful" tips to this screen, along the lines of "do you like this image?" or "get entertainment from the Windows store" (or something like that). I don't know how take a screenshot of this pre-login screen, but if you doubt me, I can probably take a photo with my camera. Anyway, is  there a way to stop Redstone 4 from giving all these tips on the pre-login screen? When you actually click/tap somewhere other than on the tips, they do go away and the password box pops in. But I dislike the visual clutter these tips provide.  N.B.: after a bit more googling, it looks like the official name for this pre-login screen is the "lock screen".

My Windows 10 Home Edition computer frequently pops up various ads for Microsoft services. For example, just now it popped up a dialog that said "Make logging in even easier! Install Microsoft Authenticate" or something like that. How can I disable this sort of activity?


I saw this posted about a year ago () but figured it was worth asking again -- is this possible? My usual workflow with ArcGIS is to export to AI then edit the layers that way, is there some way to do that from QGIS? Now I just get everything in one huge layer. Thanks.

In ArcMap, when you export data to PDF it preserves the layering within the PDF so that you can turn on/off individual map layers (within the PDF itself).  When I export from QGIS to PDF, I don't appear to have the option for this.  Does QGIS support preserving layers when exporting to PDF?  Is there a special setting needed to enable this capability?  Or has anyone wrote a plugin for this feature?


I've installed emacs via apt-get but then I uninstalled it but this package still remained installed.  When I try to uninstall it it says:  sudo apt-get remove emacsen-common  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  gir1.2-webkit-3.0 : Depends: libwebkitgtk-3.0-0 (>= 2.4.6) but it is not going to be installed E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.   How can I fix this and uninstall all traces of emacs?  Now I even have this error:  sudo apt-get remove emacsen-common  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  update-manager : Depends: ubuntu-release-upgrader-gtk but it is not going to be installed                   Depends: update-notifier E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

I have a bug-problem with the apt-packages of emacs:  >>Error occurred processing debian-ispell.el: File error (("Opening input file" "no such file or directory" "/usr/share/emacs23/site-lisp/dictionaries-common/debian-ispell.el")) >>Error occurred processing ispell.el: File error (("Opening input file" "no such file or directory" "/usr/share/emacs23/site-lisp/dictionaries-common/ispell.el")) >>Error occurred processing flyspell.el: File error (("Opening input file" "no such file or directory" "/usr/share/emacs23/site-lisp/dictionaries-common/flyspell.el")) emacs-install: /usr/lib/emacsen-common/packages/install/dictionaries-common emacs23 failed at /usr/lib/emacsen-common/emacs-install line 28, <TSORT> line 30. dpkg: error processing emacs23-lucid (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of emacs:  emacs depends on emacs23 | emacs23-lucid | emacs23-nox; however:   Package emacs23 is not installed.   Package emacs23-lucid which provides emacs23 is not configured yet.   Package emacs23-nox which provides emacs23 is not installed.   Package emacs23-lucid is not configured yet.   Package emacs23-nox is not installed. dpkg: error processing emacs (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.          Errors were encountered while processing:  emacs23-lucid  emacs E: Sub-process /usr/bin/dpkg returned an error code (1)   In fact I would be satisfied with just emacs23-nox, a couple of plugins - from apt. But I can neither --purge nor --purge reinstall, nor remove the packages. It always processes until this certain bug. I did some google-searching, found some stuff on Launchpad suggesting:  sudo apt-get install --reinstall --purge emacsen-common   But this is the same... so I hope there a way to tell app to just remove everything releated to emacs, and to start from scratch again?  Thanks, Marius


Is there any chance to work together lens and filter holder: - Samyang AE 8 F3.5 CS II fish-eye - Samyang SFH-14?

I am toying with the idea of picking up either the  or the  lens.  These lenses have a built-in petal-shape hood and a "bulb-like" front element. I came across a few reviews about the 14mm f2.8 lens but all of which mentioned the "unusuall" front element and the if so special lens cap that should always be on the lens when not in use. At least  says it is not possible to mount front filters on these lenses. Surely, there is a way...  In situations where I would be normally using these lenses I would want to be able to use ND filters. Is there any way to filters to these type of lenses and if so how and what type?


I have an angular component that needs to cycle through an array. Below, I have an array and a global variable called currentAlbum which will hold the value of the album currently being viewed. The below works, but with some odd behaviour. Question 1 Firstly, even though it cycles through correctly, i added console logs to make sure the if statement worked correctly and that it'll begin from the beginning again after reaching the end. The 'currentAlbum' console log will always be one behind of where it appears on screen. Any obvious reason for that? For example, on screen album 3 will be present, the console log will say album 2. Question 2 I also have 5 buttons on the screen, each one, when clicked will show the selected album. This is a simple this.currentAlbum = selectedValue(selectedValue being received from the HTML click). However, when doing this, the timer continues to run. If the timer is five seconds and I click a carousel button at 4 seconds, the new album will show for 1 second before changing to the next. Is there a way to reset this value? (I've also read that setTimeout is a better approach...?)   currentAlbum: number = 1;    albumsArray = [     { title: "Album 1", index: 1 },     { title: "Album 2", index: 2 },     { title: "Album 3", index: 3 },     { title: "Album 4", index: 4 },     { title: "Album 5", index: 5 },   ]    ---------    ngOnInit() {      this.theCarousel();   }      theCarousel() {     setInterval(() => {       if (this.albums == 5){         this.currentAlbum = 1;         console.log('this is album 5)       } else {         this.currentAlbum++;         console.log('this is not album 5)       }     }, 2000);   }

I am using setInterval(fname, 10000); to call a function every 10 seconds in JavaScript. Is it possible to stop calling it on some event?   I want the user to be able to stop the repeated refresh of data.


I generate a list and each element in the list is a list too. I do it using a function with a 'for' loop in it. When I update the single value of the list it's updated in each sub-list instead.  I've noticed that when I create a list manually like:  array = [['O', 'O', 'O'], ['O', 'O', 'O'], ['O', 'O', 'O']]  all works as expected.  But when I use my function which produces exactly the same output it fails.   def array_generation(size):     array = []     row = ['O'] * size     for i in range(size):         array.append(row)     return array  myArray = array_generation(3) myArray[0][0] = "S"   Actual Result: [['S', 'O', 'O'], ['S', 'O', 'O'], ['S', 'O', 'O']]  Expected Result: [['S', 'O', 'O'], ['O', 'O', 'O'], ['O', 'O', 'O']]

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


I really need a good book with some solved exercises about Linear Algebra and Affine Geometry (orthonormal basis, rotations, etc.). I want to understand the algorithms to solve that kind of problems but I can't understand the theory, it's too unclear and I think that some exercises can help me a lot. Thank you!  EDIT: I want a book which present a lot of exercises with complete solutions, especially to prepare for exams and for better understanding  EDIT 2 : I really appreciate if you can recommend a book which contains : system of vectorial equations, rotation of basis, etc. I don't know why, but in general these concepts are missed from the books.

I plan to self-study linear algebra this summer. I am sorta already familiar with vectors, vector spaces and subspaces and I am really interested in everything about matrices (diagonalization, ...), linear maps and their matrix representation and eigenvectors and eigenvalues. I am looking for a book that handles every of the aforementioned topics in details. I also want to build a solid basis of the mathematical way of thinking to get ready to an exciting abstract algebra next semester, so my main aim is to work on proofs for somehow hard problems. I got Lang's "Intro. to Linear Algebra" and it is too easy, superficial.  Can you advise me a good book for all of the above? Please take into consideration that it is for self-study, so that it' gotta work on its own. Thanks.


That evening, Dudley paraded around the living room for   the family in his brand-new uniform. Smeltings' boys wore maroon   tailcoats, orange knickerbockers, and flat straw hats called boaters.   They also carried knobbly sticks, used for hitting each other while   the teachers weren't looking. This was supposed to be good training   for later life.        As he looked at Dudley in his new   knickerbockers, Uncle Vernon said gruffly that it was the proudest   moment of his life. Aunt Petunia burst into tears and said she   couldn't believe it was her Ickle Dudleykins, he looked so handsome   and grown-up. Harry didn't trust himself to speak. He thought   two of his ribs might already have cracked from trying not to laugh.      (Harry Potter and the Sorcerer's Stone)   Does trust mean “to commit or consign with trust or confidence" (, trust.19)?

As he looked at Dudley in his new knickerbockers, Uncle Vernon said gruffly that it was the proudest moment of his life. Aunt Petunia burst into tears and said she couldn't believe it was her Ickle Dudleykins, he looked so handsome and grown-up. Harry didn't trust himself to speak. He thought two of his ribs might already have cracked from trying not to laugh. (Harry Potter and the Sorcerer's Stone)   What does "trust himself to speak" mean?


I have the following case: "This will be triggered from hour to hour". So if it is 9:32 the trigger will activate on 10:32. My question is: If I want to say from hour to hour BUT I want to say every hour ending in 00. So if it is 9:32 the trigger will be at 10:00. Is there some kind of expression for that?

What is the most idiomatic way to put into words a situation where a recurring event happens every hour at a certain minute. For example, consider that some event takes place at the tenth minute of each hour: 0:10AM, 1:10AM, 2:10AM, ...  My first ideas were "every hour at the tenth minute" or "every hour at minute 10". Are these options idiomatic and if not, what would be an idiomatic way of expressing this matter?


In axis environment I have a curve and a line intersecting it. How can I get components of (intersection-1), (intersection-2) etc. in axis units?  \documentclass{minimal}  \usepackage{pgfplots} \usetikzlibrary{intersections}  \begin{document}   \begin{tikzpicture}  \begin{axis} \addplot[name path global=GaussCurve] gnuplot[domain=48.00:56.00,samples=100] {exp(-0.5*((x-52.64)/1.82)**2)/(sqrt(2*pi)*1.82)}; \path[name path global=HelperLine] (axis cs:48,0.13288) -- (axis cs:56,0.13288); \draw[dashed,name intersections={of=GaussCurve and HelperLine}] (axis cs:48,0.13288) -- (intersection-2); \fill[red] (intersection-2) circle (.1cm); \end{axis}  \end{tikzpicture}  \end{document}   e.g. how to get the x component of red circle (intersection-2)?  This code generated by program from some data, so I can't use the presented values, it's just example.


I'm trying to change the spacing between itemize items in a beamer frame.  I've read that you should adjust beamer settings using the setbeamertemplate command so I'd like to follow that advice.  I can make some changes, like making the font \small and adjusting the vertical spacing before the itemize.  But wherever I try and put vspace or itemsep it seems to make no difference to the spacing between items.  Why is this, and how can I achieve, say, 5cm spacing between items using setbeamertemplate?    \documentclass{beamer} % itemsep does nothing here: \setbeamertemplate{itemize/enumerate body begin}{\vspace{1cm}\tiny\itemsep5cm} % vspace and itemsep do nothing here: \setbeamertemplate{itemize item}{\vspace{5cm}\itemsep5cm---} \begin{document} \begin{frame}{Title}{subtitle} Foo \begin{itemize} \item First \item Second \item Third \end{itemize} \end{frame} \end{document}

I'd like to modify the spacing between items in the itemize environment.   post shows how to modify a specific itemize environment (\addtolength{\itemsep}{0.5\baselineskip}).  However, I'd like to do it globally for the entire document.   post suggests the enumitem package.  However, I get an error in beamer when i use this package (just declaring it).  Any suggestions?  I'm currently using the addtolength method on all my itemize environments.  I'd like a global solution.  Thanks.


I need to get a history of which processes have run on my Windows machine, and when they were run.  However, I cannot use any third-party software, as I cannot guarantee that it will always be running.  Is there any way to get this information only using Windows built-in functionality?

How do I find out what programs have been running on my computer even if they have been stopped to the extent that  can't show a thing?  I don't use my computer alone and am sometimes suspicious.


Relatively new Java programmer and I've been taught that you can't create an instance of an abstract class. I've also done a little research and I learned that in most cases when it appears an abstract class is being created, it is actually an anonymous subclass. But here is the issue I ran into:  Java's URL class has a method openConnection that returns a URLConnection. URLConnection is an abstract class, and the Java documentation also lists all of its subclasses as abstract..... so I'm really lost. What's being returned?

I have seen this mentioned a few times and I am not clear on what it means. When and why would you do this?   I know what interfaces do, but the fact I am not clear on this makes me think I am missing out on using them correctly.   Is it just so if you were to do:  IInterface classRef = new ObjectWhatever()   You could use any class that implements IInterface? When would you need to do that? The only thing I can think of is if you have a method and you are unsure of what object will be passed except for it implementing IInterface. I cannot think how often you would need to do that.   Also, how could you write a method that takes in an object that implements an interface? Is that possible?


I was looking at the , which leads to  about T-shirts, and then from there, . However, as you can see in  and in the latter question, it seems that some of the T-shirt images have become plugs for free iTunes gift cards (once you download a certain app)! It seems as if the images are hosted on imageshack.com, but I'm not sure if that's the problem. What do we do with these images?  Also, I have a secondary question, which is: what happened to the boat-programming answer in the "Help design our T-shirts" question? I can't find it, even though it's linked to from multiple boat-programming meme explanations...

There's a very popular topic on Stack Overflow's Meta asking to . This was created because ImageShack deletes old images to free up server space, making images within older posts fail to load.  Unfortunately the situation is much worse than just deleting; it seems they're reusing old URLs for advertising purposes. In the post here about  I've just had to edit out the ImageShack images from  separate  because they've been reused as advertisements:        Can we block ImageShack across the entire Stack Exchange network?


What is the interpretation of this identity? I've tried picking elements one-by-one and grouping them, looking for geometric interpretations by drawing polygons and still no success.

I am attempting to solve this counting problem through combinatorial argument. The following is the equation I am given:   $$\sum_{i=1}^n (i-1)(n-i) = \binom{n}{3}$$  I understand that the right-hand side of this equation represents a set of $n$-elements out of which we choose 3. For example I believe we can say suppose we have a group of $n$ people and we want to choose 3 out of $n$ to be in a committee. However I'm not sure how to express the left-hand side in words. If forming a committee is an appropriate way to tackle this problem then I know the left-hand side must utilize the addition and multiplication principles, but I don't know how to put it into words. Also my intuition tells me that in solving this we should first flip $$(n-i)(i-1)$$  Thanks!


I know the API and the smartphone App of Stack Exchange doesn't support everything that is possible on the webpage.  And I also know I can do reviews on my mobile using the webbrowser and the desktop version of the page.  Is there another way like a specific app or something for doing reviews on the go?

I have recently discovered reviewing posts and am working towards the respective badges. However, the majority of the time (even now) I use the mobile app, rather than the desktop. Therefore I was very disappointed when I couldn't find a way of reviewing posts while on the app.  Feature request: add in a way for people to review posts while on the app, for both iOS and Android.  Personally, I think that having a button to access this would be best placed  in the iOS app, but that's just my opinion.  What do you think? Is this a plausible idea?


I'm working with QGIS 2.8.1. I have a project with CRS: 3947 (Central-Western France) and several layers in the same CRS. I have not activated the 'On the fly' CRS transformation.  I add the Bing Aerial layer through OpenLayers plugin. My project then automatically goes in CRS 3857 (OTF), despite the settings explained before... This is not a big issue because my vector layers display automatically follows the Bing Aerial and align perfectly.  I then create a new composer with a map window. The vector layers are perfectly aligned on the Bing Aerial background. The issue comes when I export the composer as a PDF or PNG, resulting in a big misalignment between vector layers and Bing Aerial... I don't understand why the printing process modifies what is displayed in the composer.   Any idea about this issue and how I could solve it?

I'm having trouble with the OpenLayers Plugin of Qgis and the map composer:  If I create an OSM-background layer and if I want to export this, the OSM-Layer looks perfectly all right in the normal qgis program window. But in the map composer and after export the layer has shifted relatively to my other shape layers (EPSG:32633 - WGS 84 / UTM zone 33N).  The second thing is that the output resolution of the exported osm-layer is very, very poor.   A really bad way of getting around this whole trouble would be to increase the screen resolution and make a screenshot of the map composition window of qgis. But I don't think this would be very professional. It also would cause a lot of pain :)   I'm using Qgis 1.8.0-Lisboa under Linux. The openlayers plugin is version 0.92.


OK, so I haven't upgraded to 14.04 yet. The update service has said nothing about a new LTS and I'm confused ...  Updates keep coming. Some things are working just a little different. I'm trying to deal with longstanding system projects so I'm not tempted to upgrade quite yet.  But should I? Are these piddly updates going to steer me wrong? Will Ubuntu 12.04 LTS just degrade and degrade an degrade? Why isn't update suggesting I go for the newer, brighter, shinier LTS?  Oh, and what is the meaning of life?  Cecilieaux

I'm following the , but on launching the upgrade tool I get this response:  Checking for a new ubuntu release No new release found   Am I doing something wrong? Is there a workaround?


I need to prove «If P(A) is a subset of P(B) => A  is a subset of  B», generally, I understand the main way I should prove it, but the problem is in the formal, pedantic language I have to use to prove such statement.  General proof is: 1. Let suppose «a» is any element of A 2. If «a» is in A, thus «a» is a subset of P(A)…  The problem is in the formal and pedantic way to right it, can I just write, that element «a» is a subset of P(A) or should I define additional set, which will be a subset of P(A) and element «a» will be a part of this new set.  Please, help me to write such prove in a formal way with the correct syntax.  Thanks.

I am really sure that if two sets have the same power set, then they are the same set. I just am wondering how does one exactly go about proving/showing this?  I'm usually wrong, so if anyone can show me an example where this fails, I'd like that too.  The homework just asks for true/false, but I'm wanting to show it if possible. My thoughts are that since the power set is by definition the set of all subsets of a set, if each of the two power sets are identical, we have an identity map between each set, thus it's indistinguishable which power set is a given set's power set. I hope that wasn't verbose. Since a set has only one power set, we can conclude they are in fact the same set.


I'm using a MacOS. I tried to enter this environment variable inside my .bash_profile:  export CLOUD_PASSWORD=Pass4Aa$ditya  But when I do source .bash_profile and try echo $CLOUD_PASSWORD, I get this as output:  Pass4Aa  Anything after that $ sign is getting ignored. Even when I tried adding quotes like: export CLOUD_PASSWORD="Pass4Aa$ditya"  and did source later, it is still showing the same as before. How do I create environment variables with Special Characters like $ and @ present in the value?

Many questions like 'How to type the double-quote char (")?' are being asked, and we don't want to clutter our community with the same answer (Type it as \" if not enclosed in 's, " if enclosed in 's.) So, the question is here.   You can't type special chars into a terminal like normal ones, e.g. this command will fail:  echo Updates (11)   So, how to type in these chars in the terminal as if they were normal ones?  !#$^&*?[](){}<>~;'"\|<space><tab><newline>


I am using res.cls to write my resume.  I have changed the indentation of my itemized list using:  \setlength{\itemindent}{-.5in}   This works great for the first line, but if the item goes onto the next line, the following line is not indented in this manner.     Is there anyway to fix this?

I'm trying to make an itemized list in beamer (using the  package). By default, the text of first-level bullet points is left-aligned at the same point as non-list text, and the bullet actually comes before that. I want the bullet point to be aligned with or even further right from the non-itemized text, so I added a line to indent it (\setlength etc.):  \begin{block}{Evaluation}     Compare seasonality estimated by our method with that in:     \begin{itemize}         \setlength{\itemindent}{1.5em}         \item ``Agricultural" grid cells ($p_a > 0.8$)          \item ``Non-agricultural" grid cells ($p_a < 0.2$)         \item 80\% threshold based on the land cover classification scheme for cropland discussed by \citep{Hansen:2000wm}.     \end{itemize} \end{block}   Here is a picture of the result:   Unfortunately, this solves one problem and creates another. The third item has to have a line break, and the text on the second line is not left-aligned with the rest of the itemized list text. How do I make it align?


I am able to only display point type on the map when it is opened a layer in GeoServer layer preview. I want to display other shapes such as LineString.   How can I add this to Style Editor to show different shapes on one layer?     Below is my style script which I have copied from Style Editor in GeoServer.  Is it possible to show more than one shapes style in a layer?  If I ask in a different way, is  Symbolizer able to added in the script of XML to display when a layer is opened by OpenLayers in GeoServer?  <?xml version="1.0" encoding="UTF-8"?>     <StyledLayerDescriptor version="1.0.0" xmlns="http://www.opengis.net/sld" xmlns:ogc="http://www.opengis.net/ogc"                            xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"                            xsi:schemaLocation="http://www.opengis.net/sld http://schemas.opengis.net/sld/1.0.0/StyledLayerDescriptor.xsd">         <NamedLayer>             <Name>M_DIZAYN_VANA</Name>             <UserStyle>                 <Name>SERVIS_NOKTASI</Name>                 <Title>SERVIS_NOKTASI</Title>                 <Abstract>SERVIS_NOKTASI</Abstract>                 <FeatureTypeStyle>                     <Rule>                          <PointSymbolizer>                             <Graphic>                                 <Mark>                                     <WellKnownName>square</WellKnownName>                                     <Fill>                                         <CssParameter name="fill">#a43eb4</CssParameter>                                         <CssParameter name="stroke">#000000</CssParameter>                                         <CssParameter name="stroke-width">1</CssParameter>                                     </Fill>                                 </Mark>                                 <Size>7</Size>                                                         </Graphic>                         </PointSymbolizer>                                        </Rule>                 </FeatureTypeStyle>             </UserStyle>         </NamedLayer>     </StyledLayerDescriptor>

I have a PostGIS table with geometry column. In this column I have geometries of several types (polygons, points, lines). I publish this this table on GeoServer.  Now I want to create OpenLayers layer with this data.  But how to make a style for this data?  I've already read   and don't want to create gtype in PostGIS if this possible.  I try to create new style within GeoServer but I think that do something wrong:  <?xml version="1.0" encoding="ISO-8859-1"?> <StyledLayerDescriptor version="1.0.0"  xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd"  xmlns="http://www.opengis.net/sld"  xmlns:ogc="http://www.opengis.net/ogc" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <!-- a Named Layer is the basic building block of an SLD document -->     <Rule>      <ogc:PropertyIsEqualTo>       <ogc:Function name="geometryType">        <ogc:PropertyName>the_geom</ogc:PropertyName>       </ogc:Function>       <ogc:Literal>Polygon</ogc:Literal>      </ogc:PropertyIsEqualTo>      <PolygonSymbolizer>        <Stroke>           <CssParameter name="stroke">#0000ff</CssParameter>           <CssParameter name="stroke-width">1</CssParameter>         </Stroke>      </PolygonSymbolizer>     </Rule> </StyledLayerDescriptor>   And get a error:  line 10: cvc-complex-type.2.4.a: Invalid content was found starting with element 'Rule'. One of '{"http://www.opengis.net/sld":Name, "http://www.opengis.net/sld":Title, "http://www.opengis.net/sld":Abstract, "http://www.opengis.net/sld":NamedLayer, "http://www.opengis.net/sld":UserLayer}' is expected. line 11: cvc-complex-type.2.4.a: Invalid content was found starting with element 'ogc:PropertyIsEqualTo'. One of '{"http://www.opengis.net/sld":Name, "http://www.opengis.net/sld":Title, "http://www.opengis.net/sld":Abstract, "http://www.opengis.net/sld":LegendGraphic, "http://www.opengis.net/ogc":Filter, "http://www.opengis.net/sld":ElseFilter, "http://www.opengis.net/sld":MinScaleDenominator, "http://www.opengis.net/sld":MaxScaleDenominator, "http://www.opengis.net/sld":Symbolizer}' is expected.   What am I doing wrong?  UPDATE  I try to show a points and make this rule for this geom type:   <Rule>         <ogc:Filter>                     <ogc:PropertyIsEqualTo>                 <ogc:Function name="geometryType">                     <ogc:PropertyName>the_geom</ogc:PropertyName>                 </ogc:Function>                 <ogc:Literal>Point</ogc:Literal>             </ogc:PropertyIsEqualTo>         </ogc:Filter>             <PolygonSymbolizer>         <Stroke>             <CssParameter name="stroke">#0000ff</CssParameter>             <CssParameter name="stroke-width">2</CssParameter>         </Stroke>         </PolygonSymbolizer>     </Rule>   But not see then on my map. What's wrong?


If $A \in M(n , \mathbb R) $ be such that $A^2=A$ , then is it true that $rank (A)=Trace(A)$ ? What I have done is to just observe that all the eigenvalues must be either $1$ or $0$ ; but no headway any further . Please help

If $A $ is  an  $n \times n$  matrix  over $\mathbb C$ such that $A^2=A$ then is it true  that  $\operatorname{trace} A = \operatorname{rank} A$?


I want to prove that the Ideal $I=\{f(x)\in\mathbb{Z}[x] | f(0)$ is even$\}$ is not principal in the ring $R=\mathbb{Z}[x]$. I have proved that, in fact $I=(2,x)$  Now, I think that should be enough (why not?), since the ideal I is now generated by 2 elements. However my professor followed saying:  To see that $I$ is not principal, we suppose that $I=(f(x))$ and we get to a contradiction. How do I get to that contradiction?

Hi I don't know how to show that $\langle 2,x \rangle$ is not principal and the definition of a principal ideal is unclear to me. I need help on this, please.   The ring that I am talking about is $\mathbb{Z}[x]$ so $\langle 2,x \rangle$ refers to $2g(x) + xf(x)$ where $g(x)$, $f(x)$ belongs to $\mathbb{Z}[x]$.


Many of the children who are employed as helpers, messengers, cash   boys and minor laborers in shops, foundries, factories, offices and as   venders, are the mainstay of families that live, God knows how, for   the one who should be the bread winner is an invalid, a cripple, a   paralytic, and would be in the charity hospital or the almshouse were   it not that the instinct of family unity is as strong and admirable   among the humble as among the rich.   I don't understand what "were it not that" & the last part mean. Does it mean that "it's not because that the instinct of poor families are as strong as the rich families, but thanks to the children, poor families are able to live"?

Possible Duplicate:          What is the meaning of this sentence - "Were it not for the bodies there on the ground, it would have appeared to be a normal day at the oasis."?  Does it mean something like this - If the bodies were not there on the ground, it would have appeared to be a normal day at the oasis.  Can anyone also explain the structure of this sentence and example of some similar sentences?


I generated some random data using rnorm() in R made a matrix X of 10,000 rows and 1,000 rows. The I generated 1000 zeros and ones using runif(). I stored the rows corresponding to 0 in Y in one matrix, and the values corresponding to 1 in Y in another matrix. Then I ran two-sided t-test on each row of these two matrices. I got the following p-values histogram. Why is that? What does this histogram tell me about the data?

Recently, I have found in a  a statement that p-values should be uniformly distributed. I believe the authors, but cannot understand why it is so.   Klammer, A. A., Park, C. Y., and Stafford Noble, W. (2009) . Journal of Proteome Research. 8(4): 2106–2113.


I encrypted using VeraCrypt on a Windows machine and the problem is that it doesn't auto mount and show up.  I used lsusb to find the device so it is showing up.  Bus 001 Device 011: ID 0781:5575 SanDisk Corp   How do I mount this and can I install VeraCrypt on my Ubuntu machine and un-encrypt it?

I have a number of encrypted volumes on external media encrypted either with TrueCrypt or VeraCrypt. What is the recommended way to install and use VeraCrypt under Ubuntu?


So, i opened blender 2.80.75 and ALL my mesh became invisible, i tried everything but nothing works, anyone knows how to solve this problem?

I don't know why but now, when i go in material preview or rendered (in solid mode it works fine), my object is entirely gray, or invisible idk, because it has the same color of the background. I've been working for days on this project without having this issue, it suddenly showed up. I tried opening other old projects and suddenly they all do the same so i guess it is some blender program setting that applies for all the projects, but idk how it happened cuz i didn't change anything :/, anyone got any tips?


The example below was taken from  which helps to identify a closure. for (var i = 0; i < 10; i++) {     (function f() {         var i2 = i;         setTimeout(function g() {             console.log(i2);         }, 1000);     })(); }  The following explanation was given:  For g: List the variables: console is a free variable. i2 is a free variable. Find the parent scope to which each free variable is bound: console is bound to the global scope. i2 is bound to the scope of f. In which scope is the function referenced? The scope of setTimeout. Hence console is not closed over by g. Hence i2 is closed over by g.  However I am not able to understand the bolded part - could you explain it to me?

How would you explain JavaScript closures to someone with a knowledge of the concepts they consist of (for example functions, variables and the like), but does not understand closures themselves?  I have seen  given on Wikipedia, but unfortunately it did not help.


So let me give you a bit of backstory, I went to a friend's place to play DnD and I decided to put my solar powered dice to charge on top of my friend's standing lamp with the plastic box practically touching the lightbulb. The box , the d10 and the d12 were ruined but the rest seemd in good condition (and even still glowed).  The attached image is of the surviving dice, they seem to be fine on the outside, no bumps or warps apparent. The damaged die I left with my friend as a souvenir.  My concern now is that the remaining dice might have weight issues since they were still really hot when we salvaged them. Is there any reliable way to check if their weight distribution is still fine?

I have a d20 that seems to be, well, remarkably lucky.*  How can I determine whether it's really just luck, or whether the die is in fact unfairly biased?  *) Well, I don't, really.  This is actually a spin-off from , which is specifically about determining whether a die is loaded.  This one is intended as a more general question about how to detect any kind of bias in dice, since we apparently don't have one yet.  I've posted my own answer below, but feel free to add more.


My camera has accumulated some dust on its chip over the past 3 years and I want to clean it. Do you have experience with cleaning your camera's sensors on your own with appropriate gear? Do you suggest doing it? Or should I see a professional?

Possible Duplicate:          Can anyone offer me advice on how to clean my camera's sensor?   Should I do this myself, or take the camera to a professional? Is it precarious, or easy with the right amount of care?   I have a Nikon D3000 that has a small dot off-center of the sensor. I believe it is dirt, and I would like to remove it. I'm tempted to use a cotton-bud, but I'm afraid that I might damage the sensor.  The dot appeared after a trip to a tropical area where the camera became wet. I took the lens off and a lot of moisture, and possibly some dirt, went into the camera. The lens became fogged-up.  When I returned from my trip I ran a hair dryer for (air only, without heat) 10 minutes through the battery compartment, believing this would circulate around and dry the camera. Consequently, I noticed many speckled dots around the sensor. I also believe there's a subtle but persistent haze when I look through the lens, but I could be wrong.  It's worth noting that the photos are fine, with no evidence of distortion or blurring. The camera is now dry and it's been months since this happened. But the dot on the sensor has been there since, like an itch I can't rub.


I am newb with jQuery and would appreciate your help.  I am struggling a bit with jQuery DOM manipulation, where I have an <input>, and .on("blur") it updates the DOM, by removing the <input>, and inserts a
 with the <input> value, and when you click on the
, it must update the DOM, by adding back the <input> with the value of the
.   When I click on  the
, nothing happens. Any Ideas?  My current code:    $(document).ready(function() {    var inputValueByClassName = null;    $(".divInput").on("click", function() {     alert("clicked!")     $(".divInput").replaceWith($('<input type="text" class="textInput>'));     $(".divInput").html(inputValueByClassName);   });    $(".textInput").on("blur", function() {     inputValueByClassName = $('input[type="text"].textInput').val();     console.log(inputValueByClassName);     $(".textInput").replaceWith($('
' + inputValueByClassName + '
'));   }) });  <input type="text" class="textInput" value="123">

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.