This is weird. On  I seem to have my own reputation, different from my Stack Overflow reputation. Yet, according to , there is no reputation on any meta site (other than this one, Stack Exchange Meta) As stated:     Votes on meta do not affect your reputation; your meta reputation is the same as your reputation on Stack Overflow (synchronized hourly), though you earn separate badges. You must have 5 reputation to participate on meta.   So I shouldn't have any reputation on meta. However I do, along with everybody else.    How to see your meta reputation in 3 easy steps (with )   Click on this button:   Then add any meta site that is not this one to the YOUR COMMUNITIES section with the edit button next to it. You may want to add the main site as well if it is not already there (for ease of seeing the bug feature, not required) Profit!     The problem feature will become visible - your meta account has a reputation of its own!   See it without markup on it .  If you are wondering what is going on here, this is what happened: A Stack Overflow employee saw  (animuson?) and even though  is shown, the Stack Overflow team secretly added it (steps to trigger it shown above) and it took 3 years and 6 months for someone (me!) to find it. Somebody (a moderator) should really edit that post to .  Or it could be a bug. Naw.  The Stack Overflow Team should either (#1) Remove this value altogether or (#2) Add it as a useless value to everybody's profile as well so more people can enjoy it (for the coolness factor only, no real effect). Personally, I like the idea of #2 so you can see what your rep would be on meta (no purpose other than looking cool, mind you). You can suggest your opinion in the comments/an answer if you like.  But this isn't a , this is a  report, so don't downvote this if you don't like my opinion on how Stack Overflow should handle this.  Anyway, can we fix this bug?

While using the top bar to navigate across communities, I noticed that the reputation displayed on meta sites on that list does not match the one of their corresponding main sites:    I have noticed on past situations that reputation gained takes a bit to "update" on the display on Meta sites (that is, if you gain rep on SO, for example, it will take some time for you to see your updated rep on MSO).  However, I have never noticed this behavior here, on the Sites List of the top bar. Furthermore, the "delay" here seems to be more severe, as the "outdated" rep showed is of several days ago (for example, I turned 3k on SO almost exactly a week ago, but the rep shown on MSO is still <3k).  Any idea what could be causing this behavior?    Update: 2 months later this persists: my main site rep updates correctly but their corresponding meta rep remains the same as in the image above.     Update: As per Catija's  I removed the site (MSO) and put it back in, but it didn't update the rep.   However, after removing one site (TWP Meta), waiting at least a day, and then adding it back I see that although the reputations still don't match, the number displayed did changed a bit (previously 29,924 but now 33,112):


As I am aware  posts are displayed in the "Featured on Meta" in the sidebar. The order of the posts is different on Meta Stack Exchange and other sites.   In what order (post created date, last active date, ...) are the posts displayed in the featured box?  On Meta Stack Exchange:        On Stack Overflow:

On , the number of meta posts shown on the Community Bulletin is, at moment I am writing this question, 2. Previously, there was just a single meta post linked from that block, and it was a  post; the total number of links was the same, as there was a link to a blog post more.    What are the criteria used to show the links in that block? Do the links to blog posts or event posts have the priority?  For instance, there were new posts on , and the second question linked from the block is actually the 41st question shown on the front page.    Now that the event expired, this is what the block shows, in different moments of the same day. (The screenshots have been taken at a distance of not more than 2 hours.)


I have a little program :  public class Main {   public static void main(String[] args) {     for(int p = 0;p<10;p++) {       long start  = System.currentTimeMillis();       int j = Integer.MAX_VALUE;       int d = 2;       int c = 0;       for(int i =Integer.MAX_VALUE; i>0;i--) {         if(i==Integer.MAX_VALUE)System.out.println(j);         c=j/d;       }       System.out.println(System.currentTimeMillis()-start);     }      } }   Here is the result I get:  $ java Main 2147483647 62              // Almost instantaneous 2147483647 1437            // Normal speed 2147483647 1455            // Same ...   I made sure it's not a simple bug by disabling JIT, and in that case all iterations are the same speed:  $ java -Djava.compiler=NONE Main 2147483647 26879 2147483647 26484   2 questions   Why does first itteration through external loop take so much less time then other 9 ?(every time i run this) How come, the fastest(slight difference, but still) division from those 3: c>>1, c/2, c/d is the last one ?

How do you write (and run) a correct micro-benchmark in Java?  I'm looking for some code samples and comments illustrating various things to think about.  Example: Should the benchmark measure time/iteration or iterations/time, and why?  Related:


Suppose you have a team composed of several persons. If I want to designate this team without repeating "team", which word do I have to use ? "it" or "they" ? In other words, which one of the following sentences is correct ?  The team decides whether it wants to work on this project or not. The team decides whether they want to work on this project or not.  Maybe both are correct.  In the first one, "it" stands for one single entity but associates the human sensation "I want to work on this project" whereas a team is not a human. In the second one, "they" implicitly stands for the members of the team but I am not sure of the correctness of "The team ... they ...".  I would very appreciate to have some feedback on those 2 formulations.

If there is a name of a band, like The Black Keys, do you say "The Black Keys are awesome*" or "The Black Keys is awesome"? Normally, you would say a band is 'they,' but then you would say 'they are awesome', but a band is one thing so you would say 'that band is awesome.' Which one is correct for a name like The Black Keys?


How can I pass a text from my HTML file to my WPF textbox, I'm trying to make a program wherein I will get the text from my html file then that text will be transferred to a textbox in WPF

I have snippets of Html stored in a table. Not entire pages, no  tags or the like, just basic formatting.  I would like to be able to display that Html as text only, no formatting, on a given page (actually just the first 30 - 50 characters but that's the easy bit).  How do I place the "text" within that Html into a string as straight text?  So this piece of code.  Hello World.

Is there anyone out there?
   Becomes:  Hello World. Is there anyone out there?


Most likely, pre-1990.  This is a story (book for kids) about two kids that build a spaceship. I remember the spaceship being constructed of shiny metal or tin on the exterior of the ship. I also vaguely recall them using a hammer to attach it. It was built from common materials. I believe in a garage.   It wasn't particularly realistic, and the ship should not have been able to fly.  I also remember that they were helped or joined by a alien (I think he was green). He helped them prior to blasting off into space. He might have been a neighbor.   I also vaguely recall colored stones or gems (perhaps I am mixing stories up).

I'm talking about at least two juvenile sci-fi novels, read between second and fourth  public grades (U.S.A.) which for me places them around 1956-9.  The protagonists are a brother and sister, presumably my (then) age. They are friends  with a single man, a scientist who has built a rocket ship. The scientist is little fey,  physically; a (relatively) large, round head, balding, short in stature and striking long,  thin hands and fingers.  The rocket ship's final preparation is to slop a viscous, clear gloop over EVERYTHING, inside and out from a pail with a paintbrush. In flight, there is an encounter with the moon, and a very small planet with (non-threatening) inhabitants not physically unlike the fey rocket scientist. The planet orbits either the moon or the earth, not the sun, and strangely, some kind of mushroom(!) theme runs through the books. Really.  That's it. That's all I got (I was nine at the most, fer chrissake). My recollection tells me there was concealment from parents, a particular name for the planet and people  and flight through a spatial fog. I mention these things separately because I am less sure  of them than the previous two paragraphs. The author was blissfully unrepentant of the laws  of physics:  Earth gravity on a micro-planet, fog in space and super-gloop to ready the  ricketiest rocket. Worked for me.  I'm guessing even Richard, my previous mentor/savior might not be familiar with these.  Anybody? Author, titles? Or do you just recognize one of these?


I'm not sure how to get my bibliography and citation call-outs to be generated a certain way. I'm using an elsarticle (Elseiver) template with BibTex and TexStudio. For one thing, my first citation shows up as [2]. What I want is an APA format, i.e.) (Jones et al., 2010).  Here's my setup:  \documentclass[preprint,12pt]{elsarticle} \usepackage{amssymb} \journal{NeuroImage} \begin{document} \bibliographystyle{plainnat} \begin{frontmatter} \title{TITLE} ..... \bibliography{biblio} \end{document}   What am I missing?? And thank you in advance.

I have trouble getting the form of citations I need. Once I cite I want to see authors' names and not numbers. The unconventional thing is that I have to use the documentclass elsarticle (This is editor's request), which always produce numbers. Here is it what I have  \documentclass{elsarticle} \usepackage{natbib} \usepackage[colorlinks=true,linkcolor=black, citecolor=blue, urlcolor=blue]{hyperref}  \begin{document}  \bibliographystyle{plainnat} \bibliography{references}  \end{document}   Can someone help me on this?  Here's an expanded MWE.  \documentclass{elsarticle} \usepackage{amssymb} \usepackage{graphicx} \usepackage{amsmath, mathtools} \usepackage{natbib} \usepackage[colorlinks=true,linkcolor=black, citecolor=blue, urlcolor=blue]{hyperref} \usepackage{changes} \usepackage{appendix} \usepackage{filecontents} \usepackage{multirow} \usepackage{booktabs}    \begin{document}  \section{The Model}  The main environment modifies that of \cite{Diamond1965}, into two main dimensions  \newpage  \bibliographystyle{elsarticle-harv} \bibliography{references}    \end{document}


Ancestor was born in 1832 England, lived in Minneapolis Ward 13. Column 30 ..what is the meaning of -9- .  No letters just  dash 9 dash

The last three columns in the 1910 US Census (columns 30, 31 and 32) have four numbers in them. Column 30 is supposedly about survivors of the Union or Confederate army, 31 is if you’re blind and 32 is labeled deaf and dumb.   I found the directions for the 1910 census - but I find nothing that indicates why they filled in those columns with numbers.  My example is from Chicago 1910 - and the columns show "17-5-8-0"  I don't see a pattern at all on what the numbers mean.  Below is a graphic/example of these annotations, taken from a random page of the 1910 US census.


I had not installing any packages recently, but when i launched Software center, I saw a message: "Item cannot be installed or removed..."  /i am translating dumps from foreign language, so it might be not super precise with original/      those solutions didnt work at all. I have some kind of paradox:  sudo apt-get install -f   tells me, that 2 packages will be installed: libdbus-glib-1-2:i386 libnspr4:i386 (and there is need to download 0 B/217 kB of archives) - strange; why it needs i386 deps in x64 arch system anyway?  I choose Y and it dumps:  (Reading database ... 300571 files and directories currently installed.) Unpacking libdbus-glib-1-2:i386 (from .../libdbus-glib-1-2_0.98-1ubuntu1.1_i386.deb) ... dpkg: processing error /var/cache/apt/archives/libdbus-glib-1-2_0.98-1ubuntu1.1_i386.deb (--unpack):  './usr/share/doc/libdbus-glib-1-2/changelog.Debian.gz' is different from the same file on the system Missing report of program apport, becouse MaxReports limit reached Unpacking libnspr4:i386 (from .../libnspr4_4.9.5-0ubuntu0.12.04.1_i386.deb) ... dpkg: processing error /var/cache/apt/archives/libnspr4_4.9.5-0ubuntu0.12.04.1_i386.deb (--unpack):  './usr/share/doc/libnspr4/changelog.Debian.gz' is different from the same file on the system Missing report of program apport, becouse MaxReports limit reached dpkg-deb: error: subprocess paste was killed by signal (Interrupted stream) There were errors while processing:  /var/cache/apt/archives/libdbus-glib-1-2_0.98-1ubuntu1.1_i386.deb  /var/cache/apt/archives/libnspr4_4.9.5-0ubuntu0.12.04.1_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1)   therefore I've removed /var/cache/ folder just in case;  then tried to install required deps independently:  sudo apt-get install libdbus-glib-1-2:i386   dumped:  You need to use "apt-get -f install", to repair following problems: Following packages has broken dependencies:  libnss3:i386 : Requires: libnspr4:i386 (>= 4.8.6) but it will be not installed E: Broken dependencies. Please try use "apt-get -f install" without packages (or give a solution).   so then I did:  sudo apt-get install libnspr4:i386   and it dumped:  You need to use "apt-get -f install", to repair following problems: Following packages has broken dependencies:  libgconf-2-4:i386 : Requires: libdbus-glib-1-2:i386 (>= 0.78) but it will be not installed E: Broken dependencies. Please try use "apt-get -f install" without packages (or give a solution).   both needs each one to allow install other one? paradox? i am in mess.  ps, if no solutions will be found to this I can copy packages from other working mirror pc /just dont want to clone whole partition/, which folder is used for storing this packages?

Encountered an error while updating through Synaptic Manager. Subsequent updates gave the error at the bottom of the output. I'm a noob so any help is appreciated.  al@al:~$ sudo apt-get -f upgrade Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following NEW packages will be installed:   libjack-jackd2-0:i386 The following packages have been kept back:   linux-headers-generic skype 0 upgraded, 1 newly installed, 0 to remove and 2 not upgraded. Need to get 0 B/202 kB of archives. After this operation, 493 kB of additional disk space will be used. Do you want to continue [Y/n]? y (Reading database ... 310056 files and directories currently installed.) Unpacking libjack-jackd2-0:i386 (from .../libjack-jackd2-0_1.9.8~dfsg.2-1precise1_i386.deb) ... dpkg: error processing /var/cache/apt/archives/libjack-jackd2-0_1.9.8~dfsg.2-1precise1_i386.deb (--unpack):  './usr/share/doc/libjack-jackd2-0/buildinfo.gz' is different from the same file on the system dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Errors were encountered while processing:  /var/cache/apt/archives/libjack-jackd2-0_1.9.8~dfsg.2-1precise1_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1)


I am trying to install phalcon development tools. In the documentation they said:  Create a symbolic link to the phalcon.php script:  ln -s ~/phalcon-devtools/phalcon.php /usr/bin/phalcon chmod ugo+x /usr/bin/phalcon   and after connecting to my Ubuntu server, at the step of creating symbolic link to the phalcon.php script I get an error:  ubuntu@ip-000-00-0-00:/$ sudo ln -s ~/phalcon-devtools/phalcon.php /usr/bin/phalcon sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set   How can I complete the installation?  When I try without sudo I get:  ubuntu@ip-000-00-0-00:/$ ln -s ~/phalcon-devtools/phalcon.php /usr/bin/phalcon ln: failed to create symbolic link ‘/usr/bin/phalcon’: Permission denied     I have tried all the answers from this question but still getting same errors:

I have run following command accidentally   sudo chown [username] -hR /   Now sudo su getting error:  sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set   How to Solve This?


I am trying to solve this problem, and show that it does not necessarily equal $i^{-1}$. My method so far is $$(i)^{i} \\ =e^{(i)\ln{(i)} } i = \cos(\theta)+i\sin(\theta) \Rightarrow \theta = \frac{\pi}{2}\pm2n\pi, n \in \mathbb{Z} \\ \Rightarrow i = e^{i\frac{\pi}{2}\pm2in\pi} \\ \Rightarrow \ln{(i)} = i\frac{\pi}{2}\pm2in\pi \\ \Rightarrow e^{(i)\ln{(i)} } = e^{(i)(i\frac{\pi}{2}\pm2in\pi)}\\ =e^{(-\frac{\pi}{2}\pm2n\pi)}$$  However when I raise this to the power of $i$ once more, the answer ends up becoming $i^{-1}$ once more. What am I missing here? If someone can please show me where I'm going wrong that would be fantastic!

What is $i^i$ and $(i^i)^i$. I fond some answers  but is there a clearer explanation of this? Maybe something help me to understand.


I have a windows service connecting to a SQL database. Recently, I was told to change the DB name in the connection string, all else was the same. When I attempted to connect, it threw Error 18456. With some research I found:   If I debug against the DB in visual studio on my machine, I get data If  I use SQL Server Mgmt Studio v18.2 (newest version?) on my machine, I get data If  I run it in SQL Server Mgmt Studio 2008 on my machine, I do NOT get data unless I run as Administrator   I am not SQL Server savvy and I don't know what the issue is or how to describe the issue to the DBA. Can someone help me identify the issue or give assistance in how to bring this to the DBA's attention? Thank you.  EDIT: I've installed the service code on a different server and it properly returns data. So this appears to be specific to the server and it's ability to get data from a SQL server. Additionally, both servers I am testing on have an operation which are able to connect to the Oracle. maybe this detail will spark some ideas? Unfortunately, I am not allowed to remote into the issue server as it is production, so I am unable to get much more info. Thanks again.

Message that SQL Server Log File Viewer shows:   Login failed for user [User] Error: 18456, Severity: 14, State 38   What it actually means:  Failed to open the explicitly specified database   My Question:  Is there a list somewhere of all the variations of the 18456 errors (Login failed), for each combination of severity and state, with the helpful description text?  I've had a Google but can't find anything other than specific combinations.


This question is interesting because it helps to ask for another question: What is multiplicative group of algebraic closure $\bar{\mathbb{F}}_p^*$ of $\mathbb{F}_p$? I know that for algebraic extension $\mathbb{F}_q \supset \mathbb{F}_p$, it's true that $(\mathbb{F}_q)^* =$ ciclic group on $q - 1$ element. If the answer for question in title is yes, then we know a lot of subgroups of $\bar{\mathbb{F}}_p^*$. More presicely we know, that for every n there exists subgroup $\mathbb{Z} /n\mathbb{Z} \subset \bar{\mathbb{F}}_p^*$ . I know that $\widehat{\mathbb{Z}}$ has the same property. If I'm right that  $\widehat{\mathbb{Z}} = \times_r \mathbb{Z}_r$, where $r$ is prime, and  $\mathbb{Z}_r$ is $r$-adic group. Is it true that $\bar{\mathbb{F}} _p^* =\widehat{\mathbb{Z}}$?

We know a lot of subgroups of  $\bar{\mathbb{F}}_p^*$: $\mathbb{Z}/q\mathbb{Z} \subset \bar{\mathbb{F}}_p^*$ if $q \ne p$ is prime. It easy to check using fact that $\mathbb{F}_{p^n} \subset \bar{\mathbb{F}}_p$ and the fact that for every $q \ne p$ prime there exist $n$ such that $p^n - 1$ is divisible by $q$. Is it true, that $\mathbb{Z}/(q\mathbb{Z})^m\subset \bar{\mathbb{F}}_p^*$? What about $\mathbb{Z}/(q^m\mathbb{Z})\subset \bar{\mathbb{F}}_p^*$? And  what other subgroups does it have?


Say we wanted to prove the continuity of the logarithm using the $\delta - \epsilon$ proof (and using the definition of the log as the inverse of the exponential). For any log base $a>1$ Starting with $|\log_a({x_1}) - \log_a({x_2})|<\epsilon$, We can find that if $\frac{x_1}{x_2} < a^\epsilon$ (and $\frac{x_1}{x_2}<a$), then $|\log_a({x_1}) - \log_a({x_2})|<\epsilon$ as desired. But for the $\delta$ part to come in, we need it in the form of $|x_1 - x_2|$, not $\frac{x_1}{x_2}$.  So then I thought that maybe if $|x_1 - x_2| < \frac{x_1}{x_2} -1 < a^\epsilon -1$  then we would have $|\log_a({x_1}) - \log_a({x_2})|<\epsilon$ which would mean that the function is continuous at $x_1$ and since it was arbitrary it is continuous at all x (right?).   The reason I think this is true is because we want the distance between $x_1$ and $x_2$ to be very small, so $a^\epsilon -1$ (which we would call $\delta$) would get really small as $\epsilon$ gets small. Is there a better way to arrive at this value of $\delta$? Assuming it is a valid answer

I need to prove the  continuity of $f(x)=\log x$ using a $\epsilon-\delta$ proof  These is what I have so far but am not sure how to continue  $|\log x-\log a| < \epsilon$   $\log a- \epsilon < \log x < \log a+ \epsilon$  $\frac{a}{e^\epsilon} < x < {a}e^\epsilon$  Any help is appreciated


Lemma Let $a(x) = b(x)c(x)$, where $a(x), b(x)$, and $c(x)$ have integer coefficients. If a prime number p divides every coefficient of $a(x)$, it either divides every coefficient of $b(x)$ or every coefficient of $c(x)$. PROOF: If this is not the case, let $b_r$ be the first coefficient of $b(x)$ not divisible by $p$, and let $c_t$ be the first coefficient of $c(x)$ not divisible by $p$. Now, $a(x) = b(x) c(x)$, so $\qquad a_{r + t} = b_0c_{r + t} +\cdots+ b_rc_t + \cdots + b_{r + t}c_0$ Each term on the right, except $b_rc_t$ is a product $b_ic_j$ where either $i > r$ or $j > t$. By our choice of $b_r$ and $c_t$, $\color{red}{\text{if }i > r\text{ then }p\,|\,b_i,\text{ and }j > t\text{ then }p\,|\,c_j}$. Thus, $p$ is a factor of every term on the right with the possible exception of $b_rc_n$ but $p$ is also a factor of $a_{r + t}$. Thus, $p$ must be a factor of $b_rc_n$ hence of either $b_r$ or $c_n$ and this is impossible.  Is there a typo at where it is highlighted with red in the proof? The greater than sign ">" should be replaced with less than sign "<" to become: $\qquad$ "if $i < r$ then $p\,|\,b_i$, and $j < t$ then $p\,|\,c_j$" Correct?

Theorem: If $R$ is an integral domain, then $R[x]$ is an integral domain as well.  Proof: Let $f(x)=a_0+a_1x+a_2x^2+\cdots+a_nx^n$ and $g(x)=b_0+b_1x+b_2x^2+\cdots+b_mx^m$ be two elements of $R[x]$. Let $0\leq i\leq n$ and $0\leq j\leq m$ such that $i$ & $j$ are the smalles numbers such that $a_i\ne 0$ & $b_j\ne 0$. $f(x)\cdot g(x)=\sum_{i=0}^{n+m}{c_ix^i}.$ $c_{i+j}=\overbrace{a_{i+j}b_0+a_{i+j-1}b_1+\cdots +a_{i+1}b_{j-1}}^{=0} +\overbrace{a_ib_j}^{\ne 0}+\overbrace{a_{i-1}b_{j+1}+\cdots+a_0b_{i+j}}^{=0}$ $=a_i+b_j\ne 0\Longrightarrow f(x)g(x)\ne 0$    I don't know why $a_{i+j}b_0+a_{i+j-1}b_1+\cdots +a_{i+1}b_{j-1}=0$ and $a_{i-1}b_{j+1}+\cdots+a_0b_{i+j}=0$.


So I want to put a button on a visualforce page that when pushed it will redirect the user to a new custom object page. However, this custom object has 4 various Record Types. I can construct the URLFOR to redirect to the following page and have the correct record type prepopulated in the field   The URLFOR statement that I am using is this:  <apex:outputLink style="font-size:125%" styleClass="btn" target="_top" value="{!URLFOR($Action.Relationship_Detail__c.New, null, [p3='012o0000000I2ie'])}">   What I would like that whenever I click the link it automatically pushes that continue button so that I can get to the actual creation page.

I have a custom object that has various record types. How would I construct URLFOR statement to take me to the new action for a particular record type?  URLFOR($Action.Relationship_Detail__c.New)  The RecordType I want to go to is called AccountAccountRelationship in the Record Type Name field  Also I feel like I should mention that this is part of an outputLink and the value is being set to this URLFOR


I used a Brillo pad on my cast iron skillet. It is seasoned, not enameled. I want to know if this could damage my cast iron skillet. Also can it be fixed?

I've got a new enameled cast iron skillet that I've been cleaning with stainless steel wool along with a standard dish rag.  It occurs to me that scratches in the enamel might eventually cause problems.  What's the consensus?  Is steel wool safe to use on an enameled surface?  Thanks.


In Excel 2016, I have a column with cells that contain comma delimited strings. I am trying to count the number of unique strings in the entire column.   I know how to count the number of unique comma delimited strings within one cell and I know that I could collapse the data in my column into a single cell and do it that way. The problem is that would exceed the character limit of one cell since I have too much data.  Here is an example image which shows what I am trying to do:    The number 8 in B3 is the final result I am looking to get.  I don't know if this is possible to do using an array formula but I have attempted to write down the logic of a vba function to accomplish this. What I have so far is this pseudocode:   Function UniqueK (cells As Range) As Integer     Dim count As Integer     Dim temp_array() As String     Dim final_array() As String     Dim cell As Variant  For cell In cells     temp_array = split(cell,",")     append temp_array to final_array Next cell  remove duplicates in final_array count = number of entries in final_array UniqueK = count End function   This is probably a really slow way of doing it and I was wondering if there was an easier way of accomplishing this task or if there is an existing way of doing it that I could not find. If not, are there ways to remove duplicates in a string array and ways to append a string array to the end of another string array so I can get this function to work?

I would like to count the number of unique selections from a column that contains multiple selections from a drop down list.  For example, column B3 contains,     Monday, Tuesday, Wednesday   The count function returns a value of 1 instead of 3 - is there any way to count the three days distinctly? Thank you!  Multiple selections from a drop down list was made possible using the VBA code from:


I am trying to install OpenSSL, but I am running into an error with perl Configure. I type:    perl Configure VC-WIN64A     and it does some work, but in the end I get an error saying:  checking build system type... Invalid configuration `VC-WIN64A':  machine `VC' not recognized Configure: error: /bin/sh config/config.sub VC-WIN64A failed   I tried tried make check and I received these errors, but I don't understand what they mean:  collect2.exe: error: ld returned 1 exit status make[2]: *** [Makefile:652: loadavg.exe] Error 1 make[2]: Leaving directory 'C:/Program Files/Make/make-4.2' make[1]: *** [Makefile:1088: check-am] Error 2 make[1]: Leaving directory 'C:/Program Files/Make/make-4.2' make: *** [Makefile:798: check-recursive] Error 1   I couldn't find those files in my file directory does that mean I installed Make incorrectly? Thank you for helping.  EDIT: This is not a duplicate question like the one linked... That question has nothing to do with my problem so I don't know why it was linked. I still can't get perl to recognize my machine.

After following the instructions in INSTALL.W64 I have two problems:   The code is still written to the "out32" folder. I need to be able to link to both 32-bit and 64-bit versions of the library on my workstation, so I don't want the 64-bit versions to clobber the 32-bit libs. The output is still 32-bit! This means that I get "unresolved external symbol" errors when trying to link to the libraries from an x64 app.


I am newbie for about system calls. In sample code always used int x=read(...) But man page shows different read functions. What is the difference between them? And how to use read(1) instead of read(2)?

For example: man(1), find(3), updatedb(2)?   What do the numbers in parentheses (Brit. "brackets") mean?


I'm a Ukrainian, so when I try to download update for Ubuntu (for example by Terminal) or some programs via the vanilla store, then connection gets aborted. It happens because the Ukranian goverment has passed a law that blocks the Russian node in Ubuntu CDN. What can I do to avoid it? For example, is there any way of changing my default node?

I have a Lucid Server (10.04) set up and I would like to change the mirror from US (or any other country) to the Main Ubuntu Mirror.  For example my two first entries in sources.list are:  deb http://us.archive.ubuntu.com/ubuntu/ lucid main restricted deb-src http://us.archive.ubuntu.com/ubuntu/ lucid main restricted   In a Desktop environment I would select the main mirror like this:    But how do I do that from the terminal as I don't have a graphical environment installed!


I'm trying to add an overlay over a div which houses an image. I've seen approaches which add an overlay to background images, but can't seem to figure out why it doesn't work for divs?  Approach:    .featured-image {   height: 338px;   position: relative;   overflow: hidden; }  .overlay {   background-color: rgba(0, 0, 0, 0.6);   width: 100%;   height: 100%;   z-index: 2; }

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'm using TeXlive 2020. I've organized my project files as: sb-mathematics     c_chapter-01.tex     c_chapter-02.tex     prd_mathematics.tex env_studentbook.tex project_studentbook.tex  Compiling the project_studentbook.tex file doesn't generate any pdf file. Other files generated are: project_studentbook.log project_studentbook.tuc  What am I missing? project_studentbook.tex \startproject project_studentbook \environment env_studentbook  \product prd_mathematics  \stopproject  env_studentbook.tex \startenvironment env_studentbook \project project_studentbook  \usepath[{sb-mathematics}]  \stopenvironment  prd_mathematics.tex \startproduct prd_mathematics \project project_studentbook \environment env_studentbook  \component c_chapter-01 \component c_chapter-02  \stopproduct  c_chapter-01.tex \startcomponent c_chapter-01 \product prd_mathematics  \chapter{A chapter}  \stopcomponent  c_chapter-02.tex \startcomponent c_chapter-01 \product prd_mathematics  \chapter{Another chapter}  \stopcomponent

If I have  project.tex  \startproject project \product one \product two \endproject   and the corresponding product files, is there an easy way to process all product files, so I get  one.pdf  two.pdf  at once?


I am inclined to think that 'to suck your teeth' is a possible description for the sound 'tsk'. Is there any good source to support (or dismiss) my assumption?  By 'tsk' I mean the onomatopoeia for a dental click sound that is used by English speakers to signify impatience, disapproval or reluctance.   For those who think I am asking "why 'tsk' is written for the sound of disapproval", hence is a duplicate of a question asked some years ago, let me say that I am aware of that question, and no, that is not what I am asking.

Wikipedia says , which isn't true at all.  For instance, there's the one usually done twice in rapid succession with the tongue against the upper side teeth/gums - to "gee up" a horse, indicate "mock-conspiratorial" agreement, etc.  So far as I know, we don't even attempt an onomatopoeic written representation of that one, but the one formed by suction against the back of the front teeth/palate is normally written as either "tut" or "tsk". Sometimes people actually say "tut" or "tut-tut" (presumably, influenced by the written form).  But I've never heard anybody say anything remotely resembling "tsk". So where does the "k" come from in that written representation?


Hi How to center the form in the middle of its enclosing ? I really tried reading similar questions and found some, but the solutions dont work on my code. I tried both text-align: center AND margin: 0 auto. On both form, div, AND input tags. What have I missed?               input {                 display: block;             }             .content {                 box-sizing: border-box;                 position: relative;                 height: 10em;                 width: 50%;                 padding: 1em;                 margin: 0 auto;                  background: grey;                 text-align: center;             }             form {                 text-align: center;             } <!DOCTYPE html>

Portal

         <form class="form">             <input type="text">             <input type="password">         </form>

How can I horizontally center a
 within another
 using CSS?

Foo foo


I am trying to use biblatex and biber on texmaker. I updated all of the packages as per the post here:  but I still get the following error  INFO - This is Biber 2.12 INFO - Logfile is 'test.blg' INFO - Reading 'test.bcf' ERROR - Error: Found biblatex control file version 3.4, expected version 3.5. This means that your biber (2.12) and biblatex (3.11) versions are incompatible. See compat matrix in biblatex or biber PDF documentation. INFO - ERRORS: 1  Process exited with error(s)   I am a bit puzzled because MikTex Package manager shows that my biblatex version is 3.12 and my biber is 2.12 but the error message states that my biblatex control file version is 3.4! I'm not sure what that means.  I did update package database in MikTex after updating all of the packages.

Every once in a while after updating MiKTeX, the installation gets into an inconsistent state. This might be a problem with the packages (an example is described in ), but sometimes packages are split or renamed. The cases I remember are when  and when miktex-etex-base-2,9 was renamed to miktex-etex-base-2.9 (if I recall correctly; I am sure it was either that or something very similar). In each case the MiKTeX Update process suggested to remove the "old" packages but it didn't give the user any hints about him having to manually add the respective replacement packages back in the package manager to get one's MiKTeX installation back into a usable state.  What are best practices for keeping MiKTeX up to date? Note that I'm not asking about installing new packages or fonts in general; there are other questions covering this area.   In which order should one execute the Update process and the Synchronization of the repository? , it is recommended to check the MiKTeX homepage before updating. What else should one do? When and in which order (and why) should one execute the "Refresh FNDB" and "Update Formats" processes within the MiKTeX Options menu? What else can happen? Other advice?


I currently have the following table;  Invoice   Client   Purchase Order 1000      A1       1234 1000      A1       1235 1001      B2       1236 1001      B2       1237 1002      B2       1238   and I'm looking for a quick way to get to;  Invoice   Client   Purchase Orders 1000      A1       1234 1235 1001      B2       1236 1237 1002      B2       1238   Any help would be appreciated!

Consider a database table holding names, with three rows:  Peter Paul Mary   Is there an easy way to turn this into a single string of Peter, Paul, Mary?


Sorry, if this question is naive.  If someone asks me,      "You didn't go to school today, right?"   If I did not, should I answer,  Yes or No?  Similarly,      "You do not like eating fish, do you?"   If I do not like eating fish, should I say Yes or No?

I faced a problem to answer a negative question, for example, when someone asks you:      Don't you have any money?   It's a yes/no question but how should one answer the question without ambiguity?  When you answer "yes", does it mean "yes, I don't have any money"? or the other way "Yes, I do have money"? the questioner may think you are agreeing to the negative, that yes, you do not have any money.  I know it's better to answer with "on the contrary" but is it possible to answer yes or no?


class A { public int a = 100; } // End of class A class B extends A { public int a = 80; } // End of class B class C extends B { public int a = 60; } // End of class C class D extends C { public int a = 40; } // End of class D  class E extends D{     public int a =10;      public void show(){         int a =0;          // Write Java statements to display the values of         // all a’s used in this file on System.out     } // End of show() Method }// End of class E   I am trying to access the variable a of the superclasses A,B,C from E but I don't understand how to do it. I tried something like this  System.out.println(super.a+" "+super.super.a+" "+super.super.super.a+" "+                    super.super.super.super.a);

I read  and thought that would easily be solved (not that it isn't solvable without) if one could write:   @Override public String toString() {     return super.super.toString(); }   I'm not sure if it is useful in many cases, but I wonder why it isn't and if something like this exists in other languages.  What do you guys think?  EDIT: To clarify: yes I know, that's impossible in Java and I don't really miss it. This is nothing I expected to work and was surprised getting a compiler error. I just had the idea and like to discuss it.


I really would love to buy a StackOverflow T-Shirt, and I guess I'm not alone.  In the first I thought about to limit it so a reputation could to avoid a overrun to your shop, but I  you "only averaged maybe $20-$50 a day in sales". So this limit does not make sense. But it would be a great thing for getting more rep ;-)  I think it should be possible to create a simple wait list formula, where you could hoarding the orders and send the order out once in quarter. That would solve your logistic problems and possible lower your shipping costs.  I really have no problem to wait some month for one StackOverflow T-Shirt as long I would get one.  However I read that you also give them away on some special events. Do you have such events even in Europe? Might be also in Germany?

There used to be a place where you could buy Stack Exchange branded gear, what happened to it?


I have a Page which contains a User Control, the Page's Data Context is bound, and so is the Contained User Control. When the Page is displayed, I can see that the User Control in the Page is displaying the values from the element as I would expect, such as Title and Description, however, in the Code Behind on the same User Control, the Data Context is null.. What am I doing wrong?   I need the Data Context so I could edit it's values within the control or change other UI elements within the page. What am I doing wrong here?  MyPage:  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" DataContext="{Binding}"   The use of the User Control with that page:  <Grid Grid.Row="1" x:Name="ContentRoot" Margin="19,9.5,19,0">        <local:ucFooControl DataContext="{Binding}"/> </Grid>   Then, where I am seeing null in User Control Code Behind, even though display elements are showing bound items.  public ucFooControl() {     this.InitializeComponent();      if (this.DataContext != null)     {         bar= (Bar)DataContext;         this.DoSomething((bar);     } }

I have a user control where the XAML of the control can bind to the appropriate properties from the parent's data context like normal (the data context propagates in xaml).   For example, I have a window whose DataContext I am setting to ObjectA for example. My user control within the window is then try to access the properties within the dataContext  So my window's xaml and code behind can both see a non-null DataContext.   My control that DataContext propagates to can see a non-null DataContext in the Xaml but not in the code behind.  What is the proper way of handling this?


I've noticed today that users can't use OpenID for login anymore. I have an old account with linked only to OpenID.  How I can login into my old Stack Overflow profile now?

NOTE: Signing up or Logging in via OpenID is no longer officially supported from any of our sites. Currently,  is still on the internet, but we are in the process of completely removing it.    Stack Overflow was an early and strong supporter of . We built our sign up/log in flow around it. We were idealistic and had , but these hopes weren't realized. Over the years people have wondered if  is . We've had to remove support as OpenID providers  or .  The time has come to part ways. The reality is OpenID support has created a ton of complexity in our codebase and the number of users actively using OpenID simply don't justify that cost. Users have spoken with their actions. You prefer Google, Facebook and Stack Exchange (aka email/PW) based account auth.     Of our 9,813,747 accounts around one-tenth of a percent are actively using OpenID (defined as having visited a site in the past 12 months). If you include all the inactive accounts it is still less than 2.9% of all accounts.  So, what is the plan?   DONE - Remove the ability to create a new account with most OpenID providers DONE - Add the ability to  DONE - Convert Launchpad (used on  ) to OAuth DONE - Remove creating new accounts with Steam from  (Steam removed support for OAuth. Only 454 accounts that use Steam have visited Arqade in the past 6 months.) DONE - We will email all users that rely on deprecated OpenID credentials and request that they  DONE - Run an announcement banner for any user who signs in with deprecated OpenID credentials urging them to  DONE - End support for logging in via OpenID  In progress - Remove  (note: only 0.2% of authorized sites in the last year have been non-Stack Exchange sites.)   Obviously, if your account relies on OpenID, then make life easy and go now and .   If you've forgotten what you credentials you use to login, then  to refresh your memory. If you don't see one of the three account types shown in the image below (Google, Facebook or Stack Exchange) then click the "add more logins" button to add one of them to your account.    Remember, SE OpenID accounts are really email/pw accounts handled through complicated OpenID code path. They will be migrated to a simpler email/pw only code path as a part of this change. No extra work required on your part.


I have two namespaces: namespace MyNamespace  and namespace MyNamespace.Test  the second one is for Unit Testing. I don't want to make the classes within "MyNamespace" public but I want the unit tests to be able to access them. I tried internal because from the  I had assumed that "MyNamespace.test" would be derived but it's not working. Do I use a different access modifier or is my namespace wrong?

We put all of our unit tests in their own projects.  We find that we have to make certain classes public instead of internal just for the unit tests.  Is there anyway to avoid having to do this.  What are the memory implication by making classes public instead of sealed?


So I already have a valid Schengen tourist visa issued from Dutch embassy on my valid Pakistan passport. However, I have not yet traveled on it to Holland so it is still un-stamped by the immigration in Holland.  Now I have to make a trip to US through Air France (tickets purchased). Since I will be transiting through Paris CDG, will I need to apply for a separate Airport Transit Visa for Paris,France?  My understanding is that a new Schengen tourist visa is not issued (from other Schengen nation) as long as there is a valid Schengen tourist visa from another state.  Is this also applicable in case of Transit Visa?

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


I've made a C++ program with uses a LaTeX template for creating PDF documents. I open the file, replace some placeholders written inside the .tex document with values of a DB, and then, I compile the filled document with pdflatex to get the corresponding PDF.  My .tex files are pretty simple: some packages (inputenc, fullpage and so on) and then a not specially long body (5 pages at most).  Since every PDF comes from the same .tex template, and they have lot of things in common (format, structure, headers), is there any way to precompile a .tex document in order to compile faster?

I try to improve the time pdflatex needs to compile my book.  Really working example  book.tex  %&preamble \begin{document} Hi \end{document}   and  preamble.tex  \documentclass{article}   I run the following commands on bash console:  $ pdflatex -ini -jobname="preamble" "&pdflatex preamble.tex\dump" $ latexmk -pdf -pvc -e '$latex=q/latex %O -shell-escape %S/' book.tex   A window opens with a (nearly) live preview that will be updated after each change in the book.tex file. The PDF Viewer evince reloads automatic when the .pdf changed.  Open Questions  I had no success to compile with the preamble of my book in the preamble.tex file.    How can I find out what I can ?  Can I precompile \newcommand's, \usepackage's?  Can I precompile a pure chapter without header?   Other aproaches for speed up  (I do not understand how to combine this ideas for best result)   pdflatex knows a -draftmode  I measured 20% faster compilation with time pdflatex -draftmode 50pagetest.tex


i previously had windows 7 on my machine when i bought it i installed win8 now but i wanted to try out ubuntu so i installed alongside win8 but there was no grub screen to choose ubuntu.. if anyone knows of a way to fix this please let me know !! THANK YOU

I'm absolutely new to Linux. I would like to know how to install Ubuntu alongside the pre-installed Windows 8+ OS.  Should I do it with Wubi, or through the Live USB/DVD?  What steps do I need to take to correctly install Ubuntu?


I am searching all *.out files from a specific directory and trying to list all the file names where the given string is not present in those files or not matching by executing the below-listed command.  find . -type f -name "*.out" -exec grep -L "226 Transfer complete." {} \;   Unfortunately, it is not listing the files which do not have the string 226 Transfer complete, instead it displayed the series of string 226 Transfer complete.  @don_crissti, as per your solution   find . -type f ! -exec grep -q 'PATTERN' {} \; -print    the 'PATTERN' present twice anywhere in my test files. If one of the locations having the 'PATTERN' and other does not have, then it is not listing the file (In my case, it should list). can I use count to validate it? Like if I get the count less than 2, then it should list the files which are considered to be erroneous.

What concise command can I use to find all files that do NOT contain a text string?  I tried this (using -v to invert grep's parameters) with no luck:  find . -exec grep -v -l shared.php {} \;   Someone said this would work:  find . ! -exec grep -l shared.php {} \;   But it does not seem to work for me.   has this example:  find ./logs -size +1c  > t._tmp while read filename do      grep -q "Process Complete" $filename      if [ $? -ne 0 ] ; then              echo $filename      fi done < t._tmp rm -f t_tmp   But that's cumbersome and not at all concise.  ps: I know that grep -L * will do this, but how can I use the find command in combination with grep to excluded files is what I really want to know.  pss: Also I'm not sure how to have grep include subdirectories with the grep -L * syntax, but I still want to know how to use it with find :)


I hope this is not too specific to be worth an answer, since there is a "simple" workaround. But I just noticed this problem and it seems really weird. Maybe someone has an explanation for me.  If I pdflatex this:  \documentclass{scrreprt}  \usepackage{filecontents} \usepackage{tocloft}  \begin{filecontents}{chapterone.tex}     \addcontentsline{toc}{chapter}{Chapter 1}     \section{Section} \end{filecontents}   \begin{document}  \tableofcontents  \clearpage  \addcontentsline{toc}{chapter}{Part A}  \include{chapterone}  \end{document}   I get this table of contents:    where I would actually expect this table of contents:    It seems the order of toc entries is switched in this combination. This only appears when using the \addtocontentsline command and when placing the second entry in an additional .aux file. If I use the \chapter command, or put both \addtocontentsline in the same file, or use \input instead of \include, everything works smoothly. If I leave out the \clearpage before the \include and therefore put the two toc-entries on different pages, they also appear in the correct order. It really is just this single combination that caused me problems.  Now, normally I would not post this since it can easily be fixed by switching out just one of these things. But it just took me almost a day to get to the bottom of the problem in a fairly complex document, and I thought it might help future visitors to see it broken down to a minimal working example. I am also curious as to what the explanation for this might be.  Thanks and greetings,  Floh

My LaTeX document is acting strangely. Here is a simplified version of it:  \documentclass{article}  \begin{document}  \tableofcontents \newpage  \addcontentsline{toc}{part}{A Part of My Document} \include{includedfile}  \end{document}   And in includedfile.tex:  \section{My Section Title} Quack.   Clearly, in the table of contents, the heading for the part should precede the one for the section, but it doesn't! What's wrong?


I am a big fan of double exposures in film photography, and was hoping to try my hand at it.   I have an  and it is an amazing 35mm rangefinder.   Like most film cameras, it has a rewind button that allows you to rewind the film. If you hold it down while you "advance" the film and reset the shutter, the film does not advance and you can shoot again on the same frame. But here is where the trouble starts.   The rewind button doesn't "unpop" immediately, and when you advance the film again, it unpops mid-stroke, and the film only advances part of the way. So the frame that you've already shot twice will only move about halfway, so you're left taking another half-frame on it. You can't advance the film again until you activate the shutter, so it appears the whole endeavor is intractable.   Has anyone done this or faced down the same issue with other Olympus rangefinders (i.e. the RC or RD?)

Film cameras typically refuse to double expose on the same frame of film. Let's take the Olympus trip 35 as the example. They're cheap as chips and don't expose unless you wind on the film. What part of the camera mechanism do I need to "modify" (destroy!) to allow it to expose as many times as I want without winding on the camera.  P.S. I know there are cameras like the  that take double exposures without modifications, and that you can re-roll the film and shoot over it again. This question is more about how to modify a camera to get a double exposure, not how to achieve a double exposure.


I've been installed the Ubuntu 14.04 in partition of hard drive other than C: drive like E: or F: drive first, then after few days later i installed the windows 7 in C:drive. After windows installation boot option or boot sequence of Ubuntu OS has gone and now windows 7 is automatically boot first and run as default and never seen the Ubuntu option now. Ubuntu Drive is also not shown in windows 7???? Kindly suggest me the solution of this problem, i want to change it and make the Ubuntu as default or run as first in my boot sequence.

I have both Windows 7 and Ubuntu installed on a shared machine. Because a lot of the non-developers use Windows, I'd like to change the boot order to make it easier for them.  Currently the boot order looks like the following:   Ubuntu 11.10 kernelgeneric *86 Ubuntu 11.10 kernelgeneric *86 (safe boot)  Memory test Memory test Windows 7 on /dev/sda6   How do I change the default order so that Windows 7 is at the top of the list?   Windows 7 on /dev/sda6 Ubuntu 11.10 kernelgeneric *86 Ubuntu 11.10 kernelgeneric *86 (safe boot)  Memory test Memory test


I am a 2nd-year PhD student. I have published two conference papers, and now I want to upload a copy to arXiv. I am aware it is common (flexible) for researchers in some areas (e.g. machine learning) to upload their papers on arXiv; However, it is uncommon in my research area/targeted publications, but I think it would be useful for wide-access (my research area: algorithm-hardware co-design for machine learning) I wonder how to know If a paper is allowed to be put on arXiv?  Do publishers have rules against that? Or It is the Journals/conferences have rules against that? Where can I find them (generally)? Are there any rules on the version of the paper that is allowed? e.g. pre-publication, camera-ready, post-publication etc.  Thanks.

An increasing number of funding organizations require publications on the research that they fund to be open access, i.e. available to the public without having to subscribe to a journal or pay a fee. Does anybody know where I can find a list of journals/publishers that do not allow material that they publish to be published this way?


Do you say,  to effectively communicate or would you say to communicate effectively. As ENL learner I get this confused quite often. Thanks.

Mark's generosity in this crisis seems to more than make up for his earlier stinginess.   Should those sentences always be avoided, or are there cases where they are valid?


So I installed Trusty tahr alongside Xp yesterday because I got bored of the stupid green hill , it works like a charm  BUT  There's only one 6gb partition for the OS and I can't even resize it should I just remove XP? Or what should I do to make it larger?

Previously, I have installed Windows 7 on my 320 GB laptop with three partitions 173, 84 and 63 GB each. The 63 GB partition was where the Windows was installed. The rest were for file containers.  Now I changed my OS to Ubuntu 12.04 LTS. I installed Ubuntu by replacing the entire Windows 7 on the 63 GB partition. The rest of the partitions remain as an NTFS Windows partition and I can still access them both (the 173 and 84 GB partitions).  Now I want to change the two partitions of Windows into an Ubuntu format partitions plus most importantly, I want to extend the 63 GB partition to more than a 100 GB because at the moment I am running out of disk space. Whenever I try to install any application, especially using wine, it always complains for a shortage of disk space.  How do I do the extending activity before I entirely format my laptop again and lose all the important files on my partitions?


Can anybody please explain the derivation of transformation of a frame rotating with constant angular velocity w.r.t. a stationary frame. It can't understand it from my book. The derivation started with assuming origins of both frames K (stationary) and Kp(rotating) are same.  So the position vectors are  equal i.e  r=rp .Then for displacement vectors we can write    $$ dr=v_p\cdot dt +  (d\phi \times r)$$  so by dividing dt I got   $$v=v_p + (\omega \times r)$$  then  $$dv = dv_p + (\omega \times dr)$$  up to there is everything ok.  I thought by dividing by $dt$ I will obtain acceleration. But that gives a different result.  I don't know why?

In this equation:  $$ \mathbf a_i\overset{\rm def}{=}\left(\frac{d^2\mathbf r}{dt^2}\right)_i=\left(\frac{d\mathbf v}{dt}\right)_i=\left[\left(\frac{d}{dt}\right)_r+\boldsymbol\Omega\times\right]\left[\left(\frac{d\mathbf r}{dt}\right)_r+\boldsymbol\Omega\times\mathbf r\right] $$ (), why is  $$\left(\frac{d}{dt}\right)_r \boldsymbol{\Omega} \times \mathbf{r}=\frac{d\boldsymbol{\Omega}}{dt}\times\bf{r}+\bf{\Omega}\times \bf{V_r}$$  In particular, I have qualms with the term  $$\frac{d\bf{\Omega}}{dt}\times\bf{r}$$  Why are we deriving the angular velocity? Why is it a derivative not of the rotational type (Namely $(\frac{d}{dt})_r$ )  Other sources do not point out that term I have problems with. In any case, I want to know how you evaluate that derivative.


There are a lot of questions that I am generally not interested in viewing either because I don't know anything about what they're discussing or don't have an interest in it. This gets cluttered after a while when you're searching for questions that are interesting to you and you keep getting the same ones over and over again. I think a useful feature would be something like Facebook's "Hide" functionality where you can just click a box or something and it will effectively hide the question from you. It would be question-centric instead of based on tags, since some questions that have tags you're interested in just aren't interesting to you (me, ha).  What say you?

I was wondering how hard it would be to enable a 'hiding' option that let me hide certain questions that I don't want to see. That way if it was a very active question that I have no interest in, I could simply click hide and not see it anymore.  The only foreseeable reason why this couldn't be implemented completely with a Greasemonkey script is that it would be nice to get replacement posts. As of right now, even the hide tag feature simply hides the questions after they were loaded. If I hid a lot of tags, I would end up getting very few questions on the home page.  This is, of course, due to caching.


I will be flying to Istanbul from Miami and I have a connection flight in Copenhagen. The flight from Miami to Copenhagen and Copenhagen to Istanbul are not operated by the same airline so I have to claim my baggage and check-in again.    The airlines are SAS and Turkish Airlines, but the website I bought them at says I need to self-transfer.  I am traveling on a Turkish passport.   Do I need a Schengen visa/transit visa for that?

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


C# supports built-in mechanism for differentiating methods that have the same names. Here is a simple example below shows how it works:  interface IVehicle{     //identify vehicle by model, make, year     void IdentifySelf();     }  interface IRobot{     //identify robot by name     void IdentifySelf(); }  class TransformingRobot : IRobot, IVehicle{      void IRobot.IdentifySelf(){         Console.WriteLine("Robot");     }      void IVehicle.IdentifySelf(){        Console.WriteLine("Vehicle");     } }   What are the use cases or benefits of this distinction? Do I really need to differentiate abstract methods in implementing classes?

What are the differences in implementing interfaces implicitly and explicitly in C#?  When should you use implicit and when should you use explicit?  Are there any pros and/or cons to one or the other?    Microsoft's official guidelines (from first edition ) states that using explicit implementations are not recommended, since it gives the code unexpected behaviour.  I think this guideline is very valid in a pre-IoC-time, when you don't pass things around as interfaces.  Could anyone touch on that aspect as well?


I have seen that the  has recently been updated. I like the way this was done, but some related badges are not grouped, like these:  First bountys:   Altruist Benefactor Investor Promoter   First Questions:   Scholar Student  Tumbleweed   Messages in chat:   Outspoken Talkative   Flagged posts:    Deputy Marshal Citizen Patrol   Used x votes in a day:   Suffrage Vox Populi   Why is that so? Could these be grouped, like some others are?

On the  (A+), there are sub-groups under the major groups.  For example, the Participation Badges group has related badges Commentator and Pundit sub-grouped, and Quorum and Convention sub-grouped.  I am of the opinion at least 1 of the following additional sub-groupings should be made:  Question Group   Student & Scholar Investor & Altruist Promoter & Benefactor   Alternately, one sub-group of Investor, Altruist, Promoter & Benefactor    Answer Group   Teacher, Enlightened, Guru Consider moving Generalist to Tag Badges Group or the bottom of the Answer Group if Tag Badges is moved immediately below Answer Group.   Participation Group   Talkative & Outspoken Caucus & Constituent Precognitive & Beta   Tag Badges  Move this group to either the bottom of all groups or below the Answer Group. Its current placement here creates a weird artificial barrier, especially with users who have no Tag Badges.  Moderation Group   Informed & Analytical Taxonomist & Synonymizer Critic & Supporter Disciplined & Peer Pressure Suffrage, Vox Populi & Civic Duty   Alternately, one sub-group of Critic, Supporter, Suffrage, Vox Populi & Civic Duty  add Cleanup and Organizer to the Editor sub-group add Citizen Patrol to the Deputy sub-group   NOTE: Since this is now status-completed, but only a select portion was completed, the rest of the request has been broken into 2 additional questions:


How do I enable source code repositories in Ubuntu 16.04 LTS?   Note: THIS IS NOT A DUPLICATE, AS THE OTHER QUESTION WAS FOR A DIFFERENT VERSION OF UBUNTU.

I need to install build-dependencies of something, how do I ensure the source code section of my software sources is enabled?


In the films, we've seen Yoda fly in military transports and escape pods, but has he ever flown a starfighter? Most Jedi do, and he's one of the oldest of them all. I would imagine he has in his youth, but his early days have barely been chronicled yet.  Is there any mention of this in any EU material? Legends or Disney canon accepted.

In a trailer for Kinect Star Wars, I saw Yoda driving a Jungle Speeder and that got me wondering. Can and has Yoda ever piloted a starfighter?  During the Clone Wars, it seems plausible that they could commission a small-sized green Jedi starfighter. Is their any indication that he has piloting experience?


I have an Acer Iconia B1-710 Tablet (codename B1-710) with Android v4.1.2 and the following:    Kernel: 3.4.0 Image: Acer_AV051_B1-710_RV04RC01_WW_GEN1 Cores: 2 CPU: MTK 8317T, 1.2 GHz RAM: 1 GB ROM: 8 GB Stock ROM Rooted with Kingo Root APK Unblocked Bootloader   I would like to upgrade to a newer version of Android, but I searched in CyanogenMod, Paranoid Android, PAC-ROM, OmniROM, SlimROM, AOKP, Resurrection Remix, Dity Unicorns, XenonHD , BlissPop and MIUI without succes.  So, Is there any flashable custom ROM for my tablet? If there's none, can I use the source to compile it?  Thanks.  EDIT: Haven't found yet a newer/custom ROM for B1-710. This is not a duplicate and this question hasn't been answered properly.  EDIT (2016-12-26): Here is the DL link for  for the Acer Iconia B1-710 tablet from the Mediatek site. The following ROMs are not available at this moment for device Tablet Acer Iconia B1-710:   Replicant OmniROM AOKP (Android Open Kang Project) MIUI Aoikaze ROM And all the others mentioned above.   The following sites/forums doesn't have custom ROM information about Tablet Acer Iconia B1-710:   XDA Developers (haven't searched throughly) Android Central Forums Samdroid Board Shipped Roms   Google useful links point to XDA that points to Acer Iconia Toolkit (useless to me without custom ROM) and to LolliAcer ROM (not a real flashable ROM that mostly bricks the tablet and in the best scenario only changes its appearence and does not update the kernel or OS version)  Taken form Acer Community:    DannyK Troubleshooter Re: Iconia Tablets - Android 4.4 KitKat 12-23-2013 08:20 AM  I read about that here: http://au.ibtimes.com/articles/530849/20131218/new-android-4-kitkat-upgrade-list-device.htm Message 6 of 18 (30,529 Views)    inuya5ha   Die Hard Re: Iconia Tablets - Android 4.4 KitKat 12-24-2013 07:11 PM  Acer Iconia B1 was released earlier this year (2013) and shipped with the obsolete Android 4.1.  Had I known in advance that Acer would leave all their tablet customers stuck with Android 4.1 I'd have stayed as far as possible from Acer tablets. No wonder why all these devices ended here in LATAM countries with cheap prices, no other country accepted them because they knew they were obsolete the second they left the factory.   [sarcasm]Great news to see that Acer won't release ANY updates whatsoever to a device manufactured this year and still announced in their tablets home page today. I'll always be a happy and loyal ACER customer and recommend their tablets to all my friends and family without doubt.[/sarcasm]

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:


The votes tab on my user profile doesn't seem to be recording my delete votes, whether a post was deleted from Moderator Dashboard or from individual posts.  For instance, on my Super User profile, it indicates that the last deletion vote I had cast was on January 9th. Given the number of posts I delete, I know this is not true.  My latest post deletion was  done about an hour ago, but my profile hasn't recorded that vote, neither has it recorded many other delete votes.

The  appears to only show posts I've voted to delete, but weren't deleted. For instance on Workplace it shows 5 posts, on UX it shows 3 posts. I have, as a mod, deleted...more than 8 posts. I can confirm this from the /admin dashboard which has a nice list of all my delete votes.  This is true for undelete votes too; undelete votes will only show undeleted posts. Active undelete votes on deleted questions won't show up in the votes tab. As a non-mod that makes it nearly impossible to track your undelete votes until the post is undeleted. (And as a mod it seems weird I can't see them either way, after all I can even search for deleted posts)  Shouldn't delete votes track deleted posts too? It could at least show the amount of posts I've voted to delete, even if we don't want to show people deleted posts. But I'll note that as both a Mod Tools user on one site and a current mod on the other, I still don't see the posts I've voted to delete that stayed deleted. I think all votes should be listed, regardless of deletion status. Barring that, at least give the proper counts at the top, even if only listing the undeleted ones.


EGMO (BAMO 2013/3)     Let $H$ be the orthocenter of an acute triangle $\triangle ABC$.   Consider the circumcenters of triangles $\triangle ABH$, $\triangle BCH$, and $\triangle CAH$. Prove that they are the vertices of a triangle that is congruent to $\triangle ABC$.   I solved the problem by showing that the circumcenters are found by taking the homothety of the original vertices to the nine-point circle with a scale factor of $-1$, thus they are congruent.  In the book, the hint said "Show that $$O_BO_C = 2(1/2)BC$$" where $O_b, O_c$ are the circumcenters. I am wondering how someone would get this using homothety.

Let $H$ be the orthocentre of an acute triangle $ABC$. Consider the circumcenters of triangle $ABH,BCH,CAH$ .Prove that they are the vertices of a triangle that is congruent to $ABC$.   My Work:   Observe that $AH$ is perpendicular to $BC$ & $O_BO_C$. (Let $O_B$ be the circumcentre of $AHC$ and the others are defined same).  Clearly,$AH\perp BC$ & $AH\perp O_BO_C$. Therefore $BC||O_BO_C$  Similarly $AC||O_AO_C$ & $AB||O_AO_B$  But, I failed to show $O_BO_C=BC$  You may also show that  $AO_C=AO_B$


I have long lost hope to get the hard numbers on how willpower works, just kinda accepted that it grows with levels and you lose it when critically wounded, and each class gains slightly different amounts.  But today I noticed I have two snipers that are identical in every way, except that one of them   has 2 more kills has 2 more willpower   (I have not yet researched Iron Will, and both ladies are drafted the usual way, not as mission rewards).  Really? Does every kill actually increases willpower by 1? If not, what's going on here?!  Screenshots:

I'm trying to make a squad of superhumans to fight the alien scum. To that end I would like to maximize my soldiers' will by reloading at the end of the mission until I'm satisfied with the result. How much will can an operative gain per rank? What's the maximum will a soldier can have at each rank up?  Bonus questions: how likely is a soldier to get the maximum will increase when ranking up? What about high rank soldiers that come as mission rewards?


I was looking at my profile on the iOS mobile app for Arqade, and I noticed that my top tag showed a score of 110.    However, I went and checked my profile on the site using my desktop, and it shows that my top tag is only 89.    My only conclusion is that the mobile app is bugged and includes my upvotes from questions with that tag as well, as I have 21 upvotes in total over my questions with that tag.

I checked yesterday and today the new homepage in the Android app. Very surprised I saw that I would almost reach a silver tag badge, that confused be because I always take a look on possible badges I can get. However I compared the score with the website and I got a total different results. See this two screenshots:


I'm having truble calculating right side of this equation  $$\cos1 + \cos 2 + \cdots + \cos n = -\frac{1}{2} + \frac{\sin(n+\frac{1}{2})}{2\sin\frac{1}{2}}$$ for $n = 1$.  I've managed to reach that $$cos1 = -\frac{1}{2} + \frac{\cos^2 1 -\cos1 -\sin^2 1}{2(1-\cos1)}$$  Can i get any tips on how to solve this equation? (If it's even correct at this point).  Thanks.

Possible Duplicate:          Prove $$\cos(\alpha) + \cos(\alpha + \beta) + \cos(\alpha + 2\beta) + \dots + \cos[\alpha + (n-1)\beta] = \frac{\cos(\alpha + \frac{n-1}{2}\beta) \cdot \sin\frac{n\beta}{2}}{\sin\frac{\beta}{2}} $$


I became accustomed to add a LIMIT 1 clause at the end of my SOQL request when I want to request only one record. Even when I don't declare an array as result. For example:  Account account = [SELECT Name FROM Account WHERE Id = 'Example' LIMIT 1];   It's just a habit. I was thinking that this was more precise and so maybe faster.   So I wanted to know if there was a way to see if there is an impact in terms of perfomance.

Is there any performance difference between these two queries?  select name from Account where id = :myId  select name from Account where id = :myId limit 1   Or, I guess more general: does salesforce stop searching after first hit when there's a unique value as a condition?


I just reset my 2018 MacBook Air and upgraded it to macOS Big Sur. One of the first things I did was install Xcode through the App Store. It downloaded just fine, but got stuck on installing. I've tried restarting my computer, but it didn't work. What should I do?

I was trying to upgrade Xcode because it didn't let me upload to apps to iTunes Connect. Now it's stuck in installing state (few hours) and doesn't start:  Xcode is being updated Xcode can not be opened while it is being updated.  What do to?


I want to loop through sqlite database if (johnny) is present in the database or not but my code is not working  if(!cursor.isAfterLast())  {     do      {         for(int i = 0; i<cursor.getCount(); i++)         {             if("johnny" == cursor.getString(1))             {                  Toast.makeText(getApplicationContext(), "string found!!! =)", Toast.LENGTH_LONG).show();             }         }                        }      while (cursor.moveToNext());     }            cursor.close(); }

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?


I just need a bit of rules clarification that I'm confused about. If I  an enchantment to an opponent in a multiplayer game, and then lose the game myself, does the enchantment leave play with me or does it remain under the control of my opponent until they lose or the game ends?

In Magic: The Gathering, the rules for a player losing in a multiplayer game are quite complex, so I'd like to try to understand them by example. I would be happy to ask each of these situations as a separate question if that is preferred, but they all seem related, and I would love to have one place to look up all of these answers.  Let's say I'm playing with two friends, Bob and Chloe, in a simple free for all. Unfortunately, I lose. When I lose, suppose the following:   I controlled an  which has exiled Bob's , does he get his bear back? I have a  on the stack targeting Chloe, does Chloe take the 2 damage still? Earlier in the turn I cast  to prevent damage to one of Bob's . If it later takes 3 damage, will that damage be prevented? Something I controlled gave Bob a 1/1 soldier token. What happens to the token? Something Chloe controlled gave me a 1/1 soldier token. What happens to the token? I had a  enchanting one of Bob's army of . What happens to the bear? I had also played  on Bob's final . What happens to the last bear? Chloe had  my . What happens to the Clone? Are there any other situations specifically addressed by the rules?


In chapter 20 of Harry Potter and the Prisoner of Azkaban, it's made very clear that Peter Pettigrew needed a wand to use his animagus transformation and escape. However, one chapter earlier we learn that Sirius Black was using and reverting his animagus transformation inside of Azkaban. This gives us the absurd conclusion that Azkaban's prisoners have wands. Clearly, something is wrong here. What's the solution? I could speculate that it can be done without a wand but Pettigrew, unlike Black, lacks the competence, but I'm hoping for something more solid and clearly present in the text.

I have 3 questions about animagus transformation and wands      Does animagus transformation require the use of a wand?   If yes, where does the wand go after the wizard transforms?   Again, if 1 is yes, how did Sirius transform into a dog in Azkaban?     Note that 2 and 3 are invalidated if the answer to 1 is no. If so, is it mentioned anywhere in the books, or can be implied by something in the books, that wand use is not required? I don't think Sirius managing to do it in Azkaban can be used as a proof here, as in Book 3 Wormtail needs a wand to change back into a rat


first(); function first(){     second();     third(); } function second(){     var b='second'; } function third(){     console.log(b); }   Getting error while trying to access variable b in third(), can you please help  console.log(b);              ^  ReferenceError: b is not defined

What is the scope of variables in javascript? Do they have the same scope inside as opposed to outside a function? Or does it even matter? Also, where are the variables stored if they are defined globally?


How is it correct to use the verbs "hear" and "listen to" when we talk about attending some events such as performances, concerts, public speeches, etc.? Is it possible to say: "Let's go and hear the Royal Orchestra at the Albert Hall this evening."? Or is it correct to say: "Let's go and listen to the Royal Orchestra at the Albert Hall."?  Or: "Let's go and hear the speech of the President." vs. "Let's go and listen to the speech of the President."  In Collins Dictionary it's put that:  "2.  verb If you hear something such as a lecture or a piece of music, you listen to it."  What is the criteria of choosing the right verb "hear" or "listen to"? As I understand while attending the performance we're paying attention, focusing on music, enjoying it? More appropriate is "listen to", isn't it?  The matter is about using these verbs talking about attending public occasions - concerts, seminars, speeches, etc. Is it correct to say: "Yesterday we went and heard the concert/speech/etc...." or it's better to say "...listened to....". Or the same in present: "I'd like to hear Mozart concert at Albert Hall tonight".

Did you hear the song?      Is this the correct expression, or should I say the following:       Did you listen to the song?


This code Find the sum of all digits that occur in a string.  Example     sumUpNumbers("2 apples, 12 oranges") = 5  //2+1+2   Can anyone explain the need for use int('0') in this code!?  int sumUpDigits(std::string inputString) {    int answer = 0;    for (int i = 0; i < inputString.size(); i++) {       if ('1' <= inputString[i] && inputString[i] <= '9') {       answer += int(inputString[i]) - int('0');     }   }    return answer; }

I have a string of digits, e.g. "123456789", and I need to extract each one of them to use them in a calculation. I can of course access each char by index, but how do I convert it into an int?  I've looked into atoi(), but it takes a string as argument. Hence I must convert each char into a string and then call atoi on it. Is there a better way?


$$I = \int_0^1\dfrac{t \ln t}{\sqrt{1-t^2}}\mathrm{dt}$$   Attempt:   Let $t = \sin x$  $\implies dt = \cos x dx$  $\implies I = \displaystyle \int_0^{\pi/2} \dfrac{\sin x \ln (\sin x) \cos x dx}{\cos x}$  $\implies  I = -\ln (\sin x) \cos x|_{0}^{\pi/2}   + \displaystyle\int_0^{\pi/2}\dfrac{\cos^2 x}{\sin x} dx$  The second integral can be "evaluated"  using $\cos^2 x = 1- \sin^2 x$. But unfortunately, there are finally two divergent integrals.   $\implies  I = -\ln (\sin x) \cos x|_{0}^{\pi/2}   + \displaystyle\int_0^{\pi/2}\csc  x dx$ + $\displaystyle\int_0^{\pi/2}\sin x dx$  How do I handle this?

Evaluation of $\displaystyle \int_{0}^{1}\frac{x\ln (x)}{\sqrt{1-x^2}}dx$   $\bf{My\; Try::}$ Let $\displaystyle I = \int_{0}^{1}\frac{x\ln x}{\sqrt{1-x^2}}dx\;,$ Put $x=\cos \phi\;,$ Then $dx = -\sin \phi d\phi$  and Changing Limit, We get  $$\displaystyle I = -\int_{\frac{\pi}{2}}^{0}\cos \phi \cdot \ln(\cos \phi )d\phi = \int_{0}^{\frac{\pi}{2}} \ln(\cos \phi)\cdot \cos \phi d\phi$$  Now Using Integration by parts, We get  $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\int_{0}^{\frac{\pi}{2}}\frac{\sin^2 \phi}{\cos \phi}d\phi$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\int_{0}^{\frac{\pi}{2}}\frac{(1-\cos^2 \phi)}{\cos \phi}d\phi$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\int_{0}^{\frac{\pi}{2}}\sec \phi d\phi-\int_{0}^{\frac{\pi}{2}}\cos \phi d\phi$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\left[\ln\left|\sec \phi+\tan \phi\right|\right]_{0}^{\frac{\pi}{2}}-\left[\sin \phi\right]_{0}^{\frac{\pi}{2}}$$  So $$\displaystyle I = \left[\ln(\cos \phi)\cdot \sin \phi\right]_{0}^{\frac{\pi}{2}}+\left[\ln\left|\sec \phi+\tan \phi\right|\right]_{0}^{\frac{\pi}{2}}-1$$  Now How can I solve after that, Help Required, Thanks


I am trying to time various algorithms for getting the intersection of two lists. On the O(n^2) algorithm I'm running into a peculiar problem where the algorithm takes more time for lists of size 2, 4, 8, and 16 than it does for lists of size 32 at which point the number begins growing as expected. The function runs a few thousand times on randomly generated lists but the times are determined by running   startTime = Thread.getCurrentThreadCpuTime(); int intersections = intersectionAlgorithm(List1, List2); //O(n^2) algorithm endTime = Thread.getCurrentThreadCpuTime(); runningTime = (endTime - startTime);   It's a minor issue but it repeats every time and is probably affecting the results elsewhere where it can't be noticed. I've tried running the program with different compile thresholds as well and that hasn't done me any help. How can I get an accurate timing of this function?

How do you write (and run) a correct micro-benchmark in Java?  I'm looking for some code samples and comments illustrating various things to think about.  Example: Should the benchmark measure time/iteration or iterations/time, and why?  Related:


In ADO.net application we have a website and windows service which are hitting same database. Since the connection string is common between them so are they sharing same connection pool.

We have a client/server application that consists of multiple EXEs. The data access layer is on the same physical tier as the client in a library shared by our EXE modules. ODBC and OleDB connection pools are managed per-process; are there techniques for sharing DB connections across processes (other than moving the data access layer to a middle tier)?


I want to see all everything in booting like what is being loaded and all instead of grub purple Interface.. So is there any way to enable text kind of mode and disable that purple screen ??

I'd like to be able to disable the Ubuntu splash screen that I see on boot with the indicator meter of progress, and replace that with a text-only readout of the boot up process (such as you can get by hitting the esc key during the splash screen).  Is this possible?  I am not asking to disable X and get to text-only login, I"m asking how to deactivate the "Ubuntu" loading screen with the dots, so that I can see text output from the boot process - processes being started, kernel messages, etc.  When I wrote this question I was not asking how to disable X altogether, only the boot splash screen.


I want to show that:     For any $B\subset \ell^1$,   $B$ is compact if and only if $B$ is bounded, closed and satisfies   $$ \forall \epsilon>0, \; \exists N\in \mathbb{N}, \; \forall \{x_n\}_{n=1}^\infty \in B, \; \sum_{n=N}^\infty |x_n| < \epsilon. $$

A set $A \subset \ell_1$ is compact if and only if $A$ is closed and bounded and given any $\epsilon >0$, there exists $n_0$ such that $\sum_{k=n}^{\infty} |x_k| < \epsilon$ for all $n> n_0$ and $x \in A$.   It's easy to prove the part assuming that $A \subset l_1$ is compact, but I am finding difficulty to prove the other part.


Hi I have this click function to show a :before and for some reason it wont show it ? Here is my code thank you! Also the .cart-toggle:before class is display:none; so it can show.  $( ".cart-toggle" ).click(function() {   $( ".cart-toggle:before" ).show( "slow", function() {     // Animation complete.   }); });   Thank you !

I'm looking for a way to change the CSS rules for pseudo-class selectors (such as :link, :hover, etc.) from JavaScript.  So an analogue of the CSS code: a:hover { color: red } in JS.  I couldn't find the answer anywhere else; if anyone knows that this is something browsers do not support, that would be a helpful result as well.


Let $\ z \not = -1$ be a complex number. Prove $\ \frac{z-1}{z+1} $ is imaginary number iff $\ |z| = 1 $  Assuming $\ |z| = 1 \Rightarrow \sqrt{a^2+b^2} = 1 \Rightarrow a^2+b^2 = 1 $ and so  $$\ \frac{z-1}{z+1} = \frac{a+bi-1}{a+bi+1} = \frac{a-1+bi}{a+1+bi} \cdot \frac{a+1-bi}{a+1-bi} = \frac{(a^2+b^2)-1+2bi}{(a^2+b^2)+1 +2a} = \frac{bi}{1+a} $$  and therefore $\ \frac{z-1}{z+1}$ is imaginary  now let me assume $\ \frac{z-1}{z+1} $ is imaginary number, how could I conclude that $\ |z| =1 $ I really can't think of any direction..  Thanks

Prove: if $|z|=1$ than $\frac{z+1}{z-1}$ is an imaginary number    I have tried to look at $$\frac{z+1}{z-1}=\frac{z+1}{z-1}\cdot \overline{\frac{z-1}{\overline{z-1}}}=\frac{z+1}{z-1}\cdot \frac{\overline{z}-1}{\overline{z}-1}$$  But did not get far


I have a .zip file with around 26k image files. I have a list of files that I want to keep in the .zip I was wondering if it was possible for me to remove files within that .zip that aren't in my file list without unzipping the actual folder (because it would take up way too much space on my computer) using Python 3. I couldn't find anything on this and was wondering if anyone knows a way I can do this Thank you!

The only way I came up for deleting a file from a zipfile was to create a temporary zipfile without the file to be deleted and then rename it to the original filename.  In python 2.4 the ZipInfo class had an attribute file_offset, so it was possible to create a second zip file and copy the data to other file without decompress/recompressing.  This file_offset is missing in python 2.6, so is there another option than creating another zipfile by uncompressing every file and then recompressing it again?  Is there maybe a direct way of deleting a file in the zipfile, I searched and didn't find anything.


I have a disk size of 1TB. But when I do du -hx . on one of the folders it shows 1.4TB. and df -k . shows 60% full.  I dont understand why is the size shown greater that disk size itself.  Thanks, Mihir

I have a Linux CentOS server, the OS+packages used around 5GB. Then, I transferred 97GB data from a Windows server to two folders on this Linux server, after calculated the disk usage, I see the total size of the two folders is larger than the disk used size.  Run du -sh on each folder, one use 50GB, the other one use 47GB  But run df -h, the used space is 96GB. (50GB + 47GB + 5GB) > 96GB  Is there any problem? Those two folders contain lots of files (1 million+). Thanks.


I've done some searching on google and wikipedia, but I can't seem to find anything. What is the quasi static process on an ideal monatomic gas where there is a decrease in entropy?  Thanks

I don't really know much about entropy but I learned recently that the entropy in the universe is constantly increasing and that perhaps someday we will reach maximum entropy and the universe will end in heat death. In order for this to be true there are two prerequisites:   Heat must constantly be created. There must be no way to destroy heat (at least no way that turns it into a more useful form of energy).   1 is certainly true. Every process creates some heat. When a person walks his/her feet hit the ground with kinetic energy and the friction creates heat.   But I don't see how 2 can be true. For one thing, heat never even leaves its place of origin (earth, another planet or a star). In order for heat to travel in requires air (or some other conductor/convector). Since there is no air in space there is also no heat. Heat leaves things only in the form of electromagnetic radiation (light) (in the case of earth, infrared).   So conversion from heat to light is certainly possible and is even found in nature. Now how do we get from light to other forms of energy? Well, photosynthesis. Solar panels. So this is possible too. If so, why will we ever run out of useful energy? Even if the rest of the universe does, can't we still reharness our own energy by converting the heat to light and light to other forms of energy?  Suppose the sun died (and leave aside the fact that it would first destroy earth with a supernova), can't we just put up a huge solar panel around earth to pick up all the infrared and convert it back to useful energy?


I am working on a game that uses commands in such a way that players disconnecting then reconnecting could break the commands. I was wondering if there is a way to detect when players join the game in 1.13.2 and run a command to give them an item. When I researched this, I found solutions for older versions using /testfor or stat.leaveGame, but those seem to be outdated in 1.13. If someone could show me the commands to use as well as the layout for command blocks/redstone that would be great. It can be for the second time they join only, or for all times that they do. Thanks

Is there any way to run a command automatically when a player joins the server? I need to do this without the use of a Bukkit plugin. I think it's possible with MCP but I want to know how!


I have a  and a servo (for which I could not found any datasheet )  So I built this circuit :          – Schematic created using   The LED is for checking if a pulse is sent and the switch SW1 is for enabling the servo.  And I have written this program for the PIC:  #include <xc.h> #define _XTAL_FREQ 40000000 #pragma config WDTE=OFF , BOREN=OFF , PWRTE=ON , MCLRE=OFF , FOSC=INTRCIO  void main(){     TRISIO = 0b0000000;     GPIO = 0b000000;     int i;     while(1==1){              GPIO = 0b111111;             __delay_ms(1);             GPIO = 0b000000;             __delay_ms(19);          for(i=0;i<50;i++){          }              GPIO = 0b111111;             __delay_ms(2);             GPIO = 0b000000;             __delay_ms(18);          for(i=0;i<50;i++){          }     }  }   Here I tried to turn the servo arm any degrees forward and backward and the for loop is here to give time for the servo to act and _XTAL_FREQ is here to set its frequency.  I even tried to transfer the GPIO settings into the for loops and add an empty for loop after them.  When I run the circuit, I face critical problems:   When I press the switch, the servo reverses about 10 degree back and forward (every time it powers on even without any feedback connected). Then if it doesn't reach 360 degree, it turns 20 degrees by 20 degrees up to the end and then stops and emit sounds like click click for every pulse sent by the PIC. (I saw LED blinks). This is not what I want to implement. If I delete every loop in it (for and while loops) and only write this in main:  GPIO = 0b111111; __delay_ms(2); GPIO = 0b000000; __delay_ms(18);    The program loops on itself and the LED blinks. Why does it loop on itself?

I have a  and I connected it to my servo () per these details:   PIC pin 1 to positive pin 8 to negative pin 2 to servo red wire (signal) servo brown wire to negative servo orange to positive (servo has three colors: brown, red and orange wires)   I programmed PIC with this code:      #include <xc.h>     #define _XTAL_FREQ 20000000     #pragma config WDTE=OFF , BOREN=OFF , PWRTE=ON , MCLRE=OFF , FOSC=INTRCIO      void main(){     TRISIO = 0b0000000;     GPIO = 0b000000;         while(1==1){             GPIO = 0b000000;             __delay_ms(1);             GPIO = 0b111111;             __delay_ms(19);         }  }   But servo does not move a bit. What is the problem?  Edit: i found out it rotate servo arm very fast to its end(the point it couldn't rotate any more then it sound like tick tick tick .....)  i changed my code to this(to reverse it back):              GPIO = 0b000000;             __delay_ms(1);             GPIO = 0b111111;             __delay_ms(19);             GPIO = 0b000000;             __delay_ms(2);             GPIO = 0b111111;             __delay_ms(18);   but it behave the same.


I have an object animal:  class Animal{  }   I want to create an object of Animal, is there a difference between the lines on the class main?  class main{      var myVar = new Animal();        // case 1      Animal myAnimal = new Animal();  // case 2 }

After discussion with colleagues regarding the use of the 'var' keyword in C# 3 I wondered what people's opinions were on the appropriate uses of type inference via var?  For example I rather lazily used var in questionable circumstances, e.g.:-  foreach(var item in someList) { // ... } // Type of 'item' not clear. var something = someObject.SomeProperty; // Type of 'something' not clear. var something = someMethod(); // Type of 'something' not clear.   More legitimate uses of var are as follows:-  var l = new List<string>(); // Obvious what l will be. var s = new SomeClass(); // Obvious what s will be.   Interestingly LINQ seems to be a bit of a grey area, e.g.:-  var results = from r in dataContext.SomeTable               select r; // Not *entirely clear* what results will be here.   It's clear what results will be in that it will be a type which implements IEnumerable, however it isn't entirely obvious in the same way a var declaring a new object is.  It's even worse when it comes to LINQ to objects, e.g.:-  var results = from item in someList               where item != 3               select item;   This is no better than the equivilent foreach(var item in someList) { // ... } equivilent.  There is a real concern about type safety here - for example if we were to place the results of that query into an overloaded method that accepted IEnumerable<int> and IEnumerable<double> the caller might inadvertently pass in the wrong type.  var does maintain strong typing but the question is really whether it's dangerous for the type to not be immediately apparent on definition, something which is magnified when overloads mean compiler errors might not be issued when you unintentionally pass the wrong type to a method.


I have a lot of story planned and it's just as lame for me as it is for them. I accidently threw a couple Mud Lashers that were too difficult after they had defeated the huge Mudbeast. This was honestly just a filler quest to waste their time but it just killed them. Sadly we're running a two person thieves guild campaign without a cleric so it's fairly difficult to scale for them so I feel like I'm to blame just as much as they are for not running away at low health.  I've thought of some solutions like removal of enchantments or skill penalties but they don't feel good enough. I was wondering what other DMs would do - how should I handle this situation?

I've gotten into a situation in my Pathfinder game where I will certainly kill my entire party (perhaps excepting one or two who can flee quickly) if I let the situation play out.  We arrived in this situation since I underestimated a monster, and it quickly proved both more powerful and more resilient than I expected to be.  Because this was my mistake and not either the players or luck I don't intend to kill the players, but there is no obvious way out, and I'd rather not resort to obvious Divine Intervention or other Deus Ex Machina.  How can I get my players out of a bad situation without leaving a sore spot in the story?  What techniques can I use at the table to make this less painful for the GM and the players?    Specific Background:  The party was returning from adventure where they lost one of their members to bad luck and bad tactics.  They were traveling through a forest where they met a Gatekeeper druid (new party member) being chased by some evil fey which they destroy.  He tells them he was chased away from a gate to the bad part of Thelanis by the fey, and agrees to help them find their way.  They decide to help him close the gate because it's a good thing to do.  They kill the minor fey and plants guarding the gate, but I threw in a WitchFire (Pathfinder Bestiary 2, CR9, Incorporeal Undead) disguised as a captured nymph.  The WitchFire quickly downed the fighter and took out one of the sorcerers as well (no one died yet).  The next obvious target would be the cleric, but I'm fairly sure attacking him would lead to the demise of the party.  When I threw in the Witchfire it was largely off the cuff ("Won't this be cool!") and I underestimated both it's offense, and the party's unpreparedness for incorporeal undead.


How do you find all permutations of a list with 3 elements in Python?  For example, input  [1, 2, 3, 4]   would return  [1, 2, 3] [1, 2, 4] [1, 3, 4] [2, 3, 4]   Thanks!

How do you generate all the permutations of a list in Python, independently of the type of elements in that list?  For example:  permutations([]) []  permutations([1]) [1]  permutations([1, 2]) [1, 2] [2, 1]  permutations([1, 2, 3]) [1, 2, 3] [1, 3, 2] [2, 1, 3] [2, 3, 1] [3, 1, 2] [3, 2, 1]


I was learning differential calculus when I came with a doubt that why do we need to find derivative of polynomial. How is it useful?

Can any one explain me what is the use of derivatives in real life. When and where we use derivative, i know it can be used to find rate of change but why?. My logic was in  real life most of the things we do are not linear functions and derivatives helps to make a real life functions into linear.  eg converting parabola into a linear function $x^{2}\rightarrow 2x$  but then i find this; derivation of $\sin{x}\rightarrow \cos{x}$  why we cant use $\sin{x}$ itself to solve the equation. whats the purpose of using its derivative $\cos{x}$. Please forgive me if i have asked a stupid questions, i want to improve my fundamentals in calculus.


how can I find out the general solution of Jensen's functional equation?   The Jensen's functional equation is :  $$ \frac{f(x)+f(x^{\prime})}{2}= f(\frac{x+x^{\prime}}{2})$$  I need the general solution, i found something on $\mathbb{Q}$ but i need general, so i need te proof

Which functions $f:\mathbb{R} \to \mathbb{R}$ do satisfy $$f\left(\frac{x+y}{2}\right) = \frac{f(x)+f(y)}{2}$$ for all $x,y \in \mathbb{R}$  I think the only ones are of type $f(x) = c$ for some constant $c\in \mathbb{R}$ and the solutions of the Cauchy functional equation $f(x+y) = f(x)+f(y)$ and the sums and constant multiples of these functions. Are there other functions which are both midpoint convex and concave?


I have two directories images and images2 with this structure in Linux:  /images/ad   /images/fe   /images/foo     ... and other 4000 folders  and the other is like:    /images2/ad   /images2/fe   /images2/foo   ... and other 4000 folders  Each of these folders contain images and the directories' names under images and images2 are exactly the same, however their content is different. Then I want to know how I can copy-merge the images of /images2/ad into images/ad, the images of /images2/foo into images/foo and so on with all the 4000 folders..

If I use mv to move a folder called "folder" to a directory that already contains "folder" will they merge or will it be replaced?