Show that $$\displaystyle\sum_{k=0}^{2n}(-1)^k \dbinom{2n}{k}^2 = (-1)^n\dbinom{2n}{n}$$ where  $n \in \mathbb{N}$   Induction didn't work, and the formula $\displaystyle\sum_{k=0}^{2n}\dbinom{2n}{k}^2 = \dbinom{4n}{2n}$ wasn't very usefull. $(1+x)^{2n} = \displaystyle\sum_{r=0}^{2n} \dbinom{2n}{r} x^{r}$ and $(1-x)^{2n} = \displaystyle\sum_{l=0}^{2n} \dbinom{2n}{l} (-1)^lx^{l}$. Multiplying the two gives me,   $$ (1+x)^{2n}(1-x)^{2n} = (1-x^2)^{2n} = \displaystyle\sum_{k=0}^{2n} \dbinom{2n}{k}(-1)^kx^{2k} = \left( \displaystyle\sum_{r=0}^{2n} \dbinom{2n}{r} x^{r}\right)\left( \displaystyle\sum_{l=0}^{2n} \dbinom{2n}{l} (-1)^lx^{l}\right) $$  Coefficient of $x^{2n}$ on left side will be $\dbinom{2n}{n}(-1)^n$. But how do I exactly calculate the coefficient of $x^{2n}$ in the R.H.S? Please give a detailed solution

The binomial expression given as follows: $$\sum_{k=0}^{2n}\left(-1\right)^{k}\binom{2n}{k}^{2}$$ results nicely into the following closed form: $$(-1)^{n}\binom{2n}{n}$$ I wish to know how exactly is it being done? I haven't been able to make much progress in solving it. My approach: \begin{align} \sum_{k=0}^{2n}(-1)^{k}\binom{2n}{k}^{2} = \binom{2n}{0}^{2} - \binom{2n}{1}^{2} + \binom{2n}{2}^{2} - ... -\binom{2n}{2n-1}^{2} + \binom{2n}{2n}^{2} \\ = \binom{2n}{0}.\binom{2n}{0} - \binom{2n}{1}.\binom{2n}{1} + \binom{2n}{2}.\binom{2n}{2} - ... -\binom{2n}{2n-1}.\binom{2n}{2n-1} + \binom{2n}{2n}.\binom{2n}{2n} \\ \text{By Symmetry of binomial coefficients} \\ = \binom{2n}{2n}.\binom{2n}{0} - \binom{2n}{2n -1}.\binom{2n}{1} + \binom{2n}{2n-2}.\binom{2n}{2} - ... -\binom{2n}{1}.\binom{2n}{2n-1} + \binom{2n}{0}.\binom{2n}{2n} \\ = \binom{2n}{2n}.\binom{2n}{0} + \binom{2n}{2n -1}.\binom{2n}{1} + \binom{2n}{2n-2}.\binom{2n}{2} + ... +\binom{2n}{1}.\binom{2n}{2n-1} + \binom{2n}{0}.\binom{2n}{2n} - 2.\left(\binom{2n}{2n -1}.\binom{2n}{1} + \binom{2n}{2n -3}.\binom{2n}{3} + ... + \binom{2n}{1}.\binom{2n}{2n-1}\right) \\ \text{By Vandermond's identity, first component, i.e.not enclosed within -2.(...) evaluates to C(4n, 2n)} \\ \binom{4n}{2n} - 2.(\binom{2n}{2n -1}.\binom{2n}{1} + \binom{2n}{2n -3}.\binom{2n}{3} + ... + \binom{2n}{1}.\binom{2n}{2n-1}) \end{align} I'm lost beyond this point. It will be extremely helpful if someone can direct me in the right direction or provide the answer to this perplexing and challenging problem. Thank you.


In episode  of Voyager, Q :     Q : If the Continnum's told you once, they've told you a thousand times. DON'T PROVOKE THE BORG!!   If Q are omnipotent / immortal / all powerful, why would Q tell his son not to provoke the Borg?   Q himself provokes humans (Janeway & Picard) quite regularly.  Do the Q fear the Borg?  Or could it perhaps be that the Q just don't want to annoy the Borg, since the Borg are possibly the most powerful guys in the galaxy (outside fluidic space) and the Q don't want to be responsible for anything the Borg do out of anger? Since the Borg could probably wipe out a good chunk of the galaxy if they felt like it.  Thanks to  for finding a clip of the scene in question:                                  UPDATE  The question :  definitely explores similar territory to this question, but no answers really address that part of the question. There are a few opinions as to why Q wouldn't want his son to antagonise the Borg, but certainly no definitive answer on whether the Q fear the Borg or not.

In the Voyager episode 'Q2', Q screams at his son "Don't provoke the Borg!". This to me is an indication that even the Q are afraid of them.   Was there ever any canon discussion about the affects of the Borg assimilating a Q? Is there any evidence that a Q can even be assimilated in their 'ascended' form?


I know that you can get all label names of picklist with the following code.  Schema.DescribeFieldResult fieldResult = Account.PicklistField__c.getDescribe(); List<Schema.PicklistEntry> values = fieldResult.getPicklistValues();  for( Schema.PicklistEntry v : values) {       System.debug('Picklist Value Label:' + v.getLabel());       System.debug('Picklist API Name:' + v.getValue()); }   Is there a way to get just the label of the specified API reference name? In addition to the following  Schema.DescribeFieldResult fieldResult = Account.Ownership.getDescribe(); List<Schema.PicklistEntry> values = fieldResult.getPicklistValues();  String result; for( Schema.PicklistEntry v : values) { //    System.debug('Picklist Value Label:' + v.getLabel());     System.debug('Picklist API Name:' + v.getValue());     if (v.getValue() == 'public') {         result = v.getLabel();     } }

I'm trying to build a Dynamic list(table) of records by selecting the Sobject and its fields.So I need to get all the fields with its API name,label,type.But I can't get the label and type.(Tried DescribeSObjectResult Class methods to get label,but it didn't help to get the label dynamically)  I tried it with the following code.  System.debug('Selection-----'+selectedObject); Map<String, Schema.SObjectType> gd = Schema.getGlobalDescribe();  Schema.SObjectType ctype = gd.get(selectedObject);  Map<String, Schema.SobjectField> fmap = ctype.getDescribe().fields.getMap();    List<FieldWrap> strList = new List<WrapMap>(); for(String s: fmap.keySet()) {     WrapMap wmp = new WrapMap();     wmp.name = s;     wmp.label = String.valueOf(fmap.get(s));     strList.add(wmp);  }   Where FieldWrap is my wrapper class with name and field of String types. I'm getting the List of API name of fields,but not the Label and type of it.Is there a way to get the label and type of field.If so, please help me.


Question  how to prove that given f(x) and g(x) is continuous then $f*g(x)$ is also continuous   All I have is that because we already know that f(x) and g(x) is continuous then $|x-a|<\delta \implies |f(x)-f(a)| $ and $|g(x)-g(a)|<\epsilon$  And I also know that   $\lim{_{x\to a}}{f(x)}g(x)=\lim{_{x\to a}}{g(x)}*\lim{_{x\to a}}{f(x)}=f(a)*g(a)$ but I don't know what to do with those information

I was trying to prove an important theorem concerning continuous functions, namely that the product of two continuous functions is continuous. I am nearly at the end of the proof but I do not understand the last step my teacher made... I'm sure some of you is able to help me out :) Thanks in advance!  Theorem  Let $f, g\colon \Bbb R \to\Bbb R $ be continuous. Then $F\colon \Bbb R\to\Bbb R$ defined by $F(x) = f(x)g(x)$ is continuous.  Proof  Let $f, g\colon \Bbb R \to\Bbb R $ be given such that $f$ and $g$ are continuous.  Let $F\colon \Bbb R\to\Bbb R$ be defined by $F(x) = f(x)g(x)$. We want to show: $F$ is continuous, that is, for all $a \in\Bbb R$, for every $\epsilon > 0$, there exists some $\delta > 0$ such that for all $x \in \Bbb R$ with $|x - a| < \delta$, $|F(x)-F(a)| < \epsilon$.  Let $a \in\Bbb R$ be given. Let $\epsilon > 0$ be given.   Let $\delta_f > 0$ be such that for all $x \in\Bbb R$ with $|x-a| < \delta_f$, $|f(x)-f(a)| < \frac\epsilon{2(|g(a)| + \epsilon)}$. Such a $\delta_f$ exists since $f$ is continuous.  Let $\delta_g > 0$ be such that for all $x \in\Bbb R$ with $|x-a| < \delta_g$, $|g(x)-g(a)| < \frac\epsilon{ 2|f(a)| + 1}$. Such a $\delta_g$ exists since $g$ is continuous.  Let $\delta_3 > 0$ be such that for all $x\in\Bbb R$ with $|x-a| < \delta_3$, $|g(x)-g(a)| < \epsilon$, which implies $|g(x)| < |g(a)| + \epsilon$. Such a $\delta_3$ exists since $g$ is continuous.  Choose $\delta = \min\{\delta_f, \delta_g, \delta_3\}$.  Then for all $x \in\Bbb R$ with $|x-a| < \delta$:  $$\begin{align}|F(x) - F(a)| &= |f(x)g(x) - f(a)g(a)| \\ &= |f(x)g(x) - f(a)g(x) + f(a)g(x) - f(a)g(a)| \\ &\le |f(x)g(x) - f(a)g(x)| + |f(a)g(x) - f(a)g(a)|\\ &= |(g(x)[f(x) - f(a)]| + |f(a)[g(x) - g(a)]|\\&= |g(x)| * |f(x)-f(a)| + |f(a)| * |g(x) - g(a)| \\ &< [|g(x)| + \epsilon] \cdot \frac \epsilon {2(|g(a)| + \epsilon)} + |f(a)| \cdot |g(x) - g(a)| \\ &= \frac\epsilon{2 + |f(a)| \cdot |g(x) - g(a)|}\end{align}$$  Problem  Now we need $|f(a)| \cdot |g(x) - g(a)|$ to be equal to $\frac \epsilon 2$ so that we have $\frac\epsilon2+\frac\epsilon 2= \epsilon$ (which completes the proof). The problem is I do not see why/how $|f(a)| \cdot |g(x) - g(a)|$ is equal to $\frac\epsilon2$. Or is there maybe an error somewhere?


I have to create a CMOS circuit from the logic function: F= ~A + B (notA or B). I made the truth table but I'm stuck here trying to make the CMOS circuit. Any ideas anyone? Thanks!    I know it's the CMOS circuit for the NAND gate. I tried to change to get the results I want but I'm stuck.

So we have AND, NOT, NAND, NOR, OR gates, but how are they created electronically/electrically?  For example, what makes NOT gate reverse the value?


After extracting a Runnable Jar in Eclipse Version 2020-12 (4.18.0), when I run it with double click the image is not displayed:  However, when using java -jar meujar.java the image is displayed:  Image addition code: JLabel lblImage = new JLabel(); lblImage.setBorder(BorderFactory.createLineBorder(Color.BLACK)); lblImage.setBounds(275, 30, 225, 225); lblImage.setIcon(new ImageIcon("logo.png"));  The addition of the label to the frame was made by windows builder, following part of the code: .addComponent(lblImage, GroupLayout.PREFERRED_SIZE, 225, GroupLayout.PREFERRED_SIZE) .addComponent(lblImage, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))

When running a Java app from eclipse my ImageIcon shows up just fine.  But after creating a jar the path to the image obviously gets screwed up.  Is there a way to extract an image from the jar at runtime so I can then open it up?  Or, is there a better way to do this?  I'd like to distribute a single jar file if possible.


When I tried executing a SQL script, which was of 500MB approx. Management Studio throws an error     Insufficient memory to continue the execution of the program   My system memory is 8GB and only 3GB is free. I am using a .bak file. I even tried SQLCMD but it's not working. Any other solution for this?  I faced this issue when I was trying to restore a database using backup of higher version (SQL Server 2014) to a lower version (SQL Server 2008 R2) using scripting method.  The compatibility level of the SQL Server 2014 database is 120.

What are my options if I need to move a database from SQL Server 2012(32bit) to SQL Server 2005(64bit)?  I know I cannot:   restore a backup of the database on SQL Server 2005 detach & attach   I know I can:   use import data wizard, and I tried it on one database, but it only moves data, and even that was troublesome as I needed to do a lot of work creating temp tables to maintain identity columns, recreating all FKs, indexes etc.    Is there an easier option?


I am writing my thesis and  really struggle with setting up bibliography. I read tons of similar issues here, but nothing seems to work for me.  I created bib file wth texlive and I am working with texmkaker. In preamble I have   \usepackage[backend=biber,style=authoryear,autocite=inline]{biblatex} \addbibresource{references.bib}   and   \printbibliography   under the chapters.   and an example of my bib reference   @article{tugrul2004effect,   title={The effect of weathering on pore geometry and compressive strength of selected rock types from Turkey},   author={Tuǧrul, Atiye},   journal={Engineering Geology},   volume={75},   number={3-4},   pages={215--227},   year={2004},   publisher={Elsevier} }   all the citations are undefined.   Does anyone know what I can do to get my citations right in the text and my reference list to actually appear in the text?

Running the minimal example  \documentclass{article} \usepackage{filecontents} \begin{filecontents*}{\jobname.bib} @ARTICLE{example,   author  = {Other, Anthony Norman},   title   = {Some things I did},   year    = {2014},   journal = {J.~Irrep. Res.},   volume  = {1},   number  = {1},   pages   = {1-10} } \end{filecontents*} \usepackage[backend=biber]{biblatex} \addbibresource{\jobname.bib} \begin{document} Hello\cite{example}. \printbibliography \end{document}   I get the warning There were undefined references.  I have read  and know that I need to run:   LaTeX Biber LaTeX   However, my editor is only set up to run BibTeX. How do I go about setting up my editor/IDE to be able to run Biber, and how do I run the LaTeX/Biber/LaTeX cycle?  Answers (sorted alphabetically by editor name)                    Answer guidelines   Each answer should be for one editor. If the editor is cross-platform, if possible give a single answer with notes covering the minor platform variations. Please edit the question to include new answers in the 'link list' Each answer should be 'stand alone', i.e. don't say 'It's almost the same as editor Y but ...' for the editor part Instructions for 'build tools' such as arara or latexmk are welcome but should explain how to set up the editor in question as not all editors allow simple addition of arbitrary tools


1. Would it be okay if I called you when I got back home? 2. Would it be okay if I called you when I get back home?  Now I believe that both the sentences follow the rule of the second conditional. What I am confused about, is if I should keep the entire sentence to the past even after following the second conditional is over to keep the tenses sense, like I did in the first sentence. Or Should I get back to present to tense after the following of the second rule part is over? Now, if you don't understand the question, just leave a comment, and I'll get back to you. :) And, which of two sentences would you use?

Would it be okay if I called you when I got back home?     Would it be okay if I called you when I get back home?       Are both the above sentences grammatically correct?  I'm still kinda confused with the tenses agreement thing.  And how backshifting works.  What i don't get is,do i have to convert the entire sentence to the past,or do i have convert certain parts of the sentence to the past. Or whether i should keep a sentence where i have past tense strictly to the past.  Like:        I was walking down the street the other day, and it hit me how the world worked.     I was walking down the street the other day, and it hit me how the world works.      Do I keep the sentence to the past? Or do I mix tenses?


I've problems with that BODMAS rule. I lost my 5 marks in the test for that. Why we should follow that DMAS rule? Why it is not any other combination? Are there any derivations for it? PS:-Sorry I'm confused with the tags with this question. I don't need any easy way to remember it.

I'm having trouble remembering PEMDAS (in regards to precedence in mathematical equations), ie:   Parentheses Exponentiation Multiplication & Division Addition & Subtraction   I understand what all of the above mean, but I am having trouble keeping this in my head. Can you recommend any tricks or tips you use to remember this.  Thanks


I just created an .  I started editing the answer just before the 5 minutes were up, and saved it just after the 5 minutes were up, so the system substituted 'added 231 characters in body' as the edit summary comment (the 'editorial' comment, explaining why the change was made).  Normally (meaning 'in times past') you could reset the text of the comment by editing again and changing the comment.  This morning, it won't let me do that.  This is not an improvement — please revert to the old behaviour where the edit summary comment can be edited too.    Re-investigation  TL;DR — reproducible, but possibly intermittent.  (First seen with Firefox 23.0.1, reproduced with Chrome 29.0.1547.65, both running on Mac OS X 10.8.4, but on two different machines.)  I just created another  to the same question as before, and I've now deleted it (so only 10K users can see it at all).  The sequence of operations I did was:   Create the answer. Within a minute or so, edit the answer, but do not set the edit summary to anything, and do not save yet. When just over 5 minutes had elapsed from answer creation, I submitted the edit.  It got an automatic edit summary 'added 606 characters in body'. Immediately review changes to answer — to see the automatic comment. Return to answer and edit it again (within a minute or so), and try to change the edit summary (only). Save the edit.  Rereview the changes — automatic comment not changed. Return to answer and edit it again this time editing both edit summary and answer body. Save the edit. Rereview the changes — automatic comment not changed. Return to answer and edit it again, changing both body and edit summary. Save the edit. Rereview the changes — this time edit summary did change! Return to answer and edit it once more, recording disbelief. Save the edit. Rereview the changes — and the changed edit summary is still in effect.   I deleted the answer (since it was anything but an answer to the question), but 10K users can see what I wrote as I was reproducing it.

Recently, I edited  to update a link to a better resource. I clicked "Save" without entering a description of the edit (edit #1).  Then I realised that the question was asked by a new user who may not be able to easily identify the change that was made. So I edited it again, this time only to add a detailed edit description (edit #2).  Since edit #2 was made during the grace period (within 5 minutes of edit #1), the system has merged them into a single edit, but only the edit comment from edit #1 was recorded in the revision history, whereas edit #2's comment was simply discarded/ignored.  I'd suggest that either the most recent (non-default) edit comment is taken or that the comments are concatenated to provide a more useful edit history


For a simple undirected graph $G$, suppose we have two vertices $v_1$ and $v_2$ such that $G-v_1 \simeq G-v_2$. Does this necessarily mean that there is an automorphism of $G$ that maps $v_1$ to $v_2$?   This is just a condition that I've assumed to be true for awhile now without thinking too hard about whether or not it's actually true. Using the condition that $G-v_1 \simeq G-v_2$ has been a useful way to characterize two vertices as being "the same," but I was wondering if this actually corresponds to automorphisms of the graph.

Can somebody give me an example of a graph on eight vertices that has a pair of pseudosimilar vertices? Or, is it not possible? If it is not possible, please do not give me a proof, as I would like to figure out how to prove it myself.     Definition: vertices $u$ and $v$ in a graph $X$ are similar if there is an automorphism of $X$ that maps $u$ to $v$. If $u$ and $v$ are similar, then the vertex-deleted subgraphs $X-u$ and $X-v$ are isomorphic. If $X-u$ and $X-v$ are isomorphic but $u$ and $v$ are not similar, we say that they are pseudosimilar.


So I've been working on Rudin's 1.1.3 for a while and I think I'm close to a figuring it out.  In the set $A$ there are positive rationals $p$ such that $p^2<2$ and we can find a rational $q$ in $A$ such that $p<q$. So we can also say $q^2<2$.  I want to say that $q=p+x$ where $x$ is very small so that I can say $p^2<q^2$ because $q^2=(p+x)^2=p^2+2px+x^2$ and that's bigger than just $p^2$  Now $p^2<q^2<2$ and I can move things around so that I get $0<q<p+(2-p^2)/(q+p)$ which I can then rearrange into what I have below.  So, unless I'm doing things wrong, I can get $p<q<p-(p^2-2)/(p+q)$  The latter part of that relation is somewhat close to what Rudin has in 1.1.3 but I still have inequalities and my denominator still has a $q$.  =Update=  So reading a helpful reply, I've simplified by attempts:  We know that $q^2<2$ and if $q=p+x$ then we have $(p+x)^2<2$. We can then the $x$ on one side and get this; $x(2p+x)<2-p^2$  But still not sure completely clear what the next methodological step is.  =Update 2=  For some reason I still can't make the connection from $2p+x = p + p +x$ and the $p +2 $. I understand that the latter expression is probably chosen due to elegance in how it will nicely simplify eventually.  For this last stage, I understand that   $0<p^2<q^2=(p+x)^2<2$ and because $(p+x)^2<2$ then either $p$ or $x$ is positive and less than $sqrt(2)$. I suppose we can think of it as $p+x<sqrt(2)$ even though we shouldn't be using sqrt(2). Like, sure, $p+x<sqrt(2)<2$ but then how do we get rid of that inequality when we're replacing that $p+x$ with $2$.  I'm pretty sure I understand the theory of what Rudin's doing and your replies, but the actual computation with the inequalities is messing me up.

First, my apologies if this has already been asked/answered.  I wasn't able to find this question via search.  My question comes from Rudin's "Principles of Mathematical Analysis," or "Baby Rudin," Ch 1, Example 1.1 on p. 2.  In the second version of the proof, showing that sets A and B do not have greatest or lowest elements respectively, he presents a seemingly arbitrary assignment of a number $q$ that satisfies equations (3) and (4), plus other conditions needed to show that $q$ is the right number for the proof.  As an exercise, I tried to derive his choice of $q$ so that I may learn more about the problem.  If we write equations (3) as $q = p - (p^2 - 2)x$, we can write (4) as   $$ q^2 - 2 = (p^2 - 2)[1 - 2px + (p^2 - 2)x^2]. $$  Here, we need a rational $x > 0$, chosen such that the expression in $[...]$ is positive.  Using the quadratic formula and the sign of $(p^2 - 2)$, it can be shown that we need   $$ x \in \left(0, \frac{1}{p + \sqrt{2}}\right) \mbox{ for } p \in A, $$  or, for $p \in B$, $x < 1/\left(p + \sqrt{2}\right)$ or $x > 1/\left(p - \sqrt{2}\right)$.  Notice that there are MANY solutions to these equations! The easiest to see, perhaps, is letting $x = 1/(p + n)$ for $n \geq 2$.  Notice that Rudin chooses $n = 2$ for his answer, but it checks out easily for other $n$.  The Question:  Why does Rudin choose $x = 1/(p + 2)$ specifically?  Is it just to make the expressions work out clearly algebraically?  Why doesn't he comment on his particular choice or the nature of the set of solutions that will work for the proof?  Is there a simpler derivation for the number $q$ that I am missing?


I want to use the \url command but want to show a different text than the url itself. So I chose \href. The problem here is that the result is in a differnt font. Is there a way to syle the shown text of \href in the \url style?

Is there a \urlstyle{tt} (or something else to that effect) for \href to make it the same font as \url links? I'm happy with any monospace font, as long as they both (\url and \href) show up the same.


I just upgraded to 15.04 and now the network connection icon shows but there is no wifi in the network options. This is on a hp dm1 bcm4313.   ifconfig only shows "eth1" and "lo"  iwconfig says no wireless   running kernel 3.19.0-17  I tried this:  HP-Pavilion-dm1-Notebook-PC:~$ lshw -C network  WARNING: you should run this program as super-user.   *-network UNCLAIMED             description: Network controller        product: BCM4313 802.11bgn Wireless Network Adapter        vendor: Broadcom Corporation        physical id: 0        bus info: pci@0000:03:00.0        version: 01        width: 64 bits        clock: 33MHz        capabilities: bus_master cap_list        configuration: latency=0        resources: memory:f0200000-f0203fff   *-network        description: Ethernet interface        product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:07:00.0        logical name: eth1        version: 06        serial: 80:c1:6e:5a:45:30        size: 10Mbit/s        capacity: 1Gbit/s        width: 64 bits        clock: 33MHz        capabilities: bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation        configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl8168e-3_0.0.4 03/27/12 latency=0 link=no multicast=yes port=MII speed=10Mbit/s        resources: irq:41 ioport:2000(size=256) memory:f0104000-f0104fff memory:f0100000-f0103fff WARNING: output may be incomplete or inaccurate, you should run this program as super-user.   then I followed this thread :    and the adapter now recognizes wifi networks BUT the connection is extremely slow.  Any ideas?

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


Hi I am looking for some python script which runs automatically when a file has been added to a folder. is it really possible?. if yes can some one send some scrpts please.thanks in advance

Is it possible to run a Python script when a file has been added to a folder?  In my scenario I have a folder that contains movies and the Python script gets the details (name, year, plot, rating, etc) from OMDb and puts them into a file, which MySQL uses.   Every time I add a movie I have to run the Python script.  I want to know if it is possible to automatically run the Python script when a file has been added to the folder?  Thanks in advance.


Prove that the following number is irrational:  $$\sqrt { 5 } +\sqrt { 3 } $$  Steps I took:  Proof by contradiction: let us assume that $\sqrt { 5 } +\sqrt { 3 } $ is rational.  If $\sqrt { 5 } +\sqrt { 3 } $ is rational, so is $(\sqrt { 5 } +\sqrt { 3 } )^{ 2 }$  $$(\sqrt { 5 } +\sqrt { 3 } )^{ 2 }=5+2\sqrt { 15 } +3= 2\sqrt { 15 } +8$$  However, this is a contradiction since $\sqrt { 15 } $ is irrational.   Is my proof good? What needs to be added and how can it be made more complete if it already isn't. Please note that I already proved that $\sqrt { 15 } $ is irrational in part (a) of the problem. This is part(b). That is why I didn't bother to prove it again. I guess you could say the irrationality of $\sqrt { 15 } $ was given when I started the proof.

Can the expression $\sqrt{n} + \sqrt{m}$ be rational if neither $n,m \in \mathbb{N}$ are perfect squares? It doesn't seem likely, the only way that could happen is if for example $\sqrt{m} = a-\sqrt{n}, \ \ a \in \mathbb{Q}$, which I don't think is possible, but how to show it?


When someone asks me "How are you doing?" Why do we answer "good" instead of "well" (adv. for doing) ?

What is a natural response to "Good to see you. How you doing?"? Will a natural response include "doing" as in "I'm doing okay" or will "I'm okay" be more natural?


guys and girls - I found Blender editing mesh tools the best for my terrain needs, I mean I just need the mesh itself for a lowsized terrain (no more then 70 by 70 quads), without any of those normal terrain editors complicated things. And I have a question - are there tools or ways, or even tricks, to render this small terrain as a top view black-and-white heightmap and save it as an image, BMP preferable but no matter? The goal is just to have heightmap image in a file for further processing. Thank you :)

I want to bake some displacement maps for Unity Engine. I want to use Cycles renderer. I have read that it's only available in Experimental version of Cycles, but when I changed Cycles to Experimental version there isn't baking type for Displacement map, there are UV, Normals, Shadows etc. but there isn't any Displacement/Depth map choice. I have Blender 2.78a (2016-10-24) downloaded yesterday. Where can I find this option or how can I enable it?


Let's say I have got 5 websites in the different hostings each.  I want to create a page for each of them but host them all together under a subdomain of ONE hosting, For example.  www.site1.com -> At hosting A www.site2.com -> At hosting B www.site3.com -> At hosting C www.site4.com -> At hosting D  www.site5.com -> At hosting E  Let's say I have got 5 websites in the different hostings each.  I want to create a page for each of them but host them all together under a subdomain of ONE hosting, For example.  www.site1.com -> At hosting A www.site2.com -> At hosting B www.site3.com -> At hosting C www.site4.com -> At hosting D  www.site5.com -> At hosting E  So :  Visiting www.site1.com should take you to what is in hosting A but if you visit www.site1.com/pageZ should take you to pages.site5.com/pageZ in hosting E(BUT YOU SHOULD STILL SEE THE SAME URL)  and the same for the rest... www.site2.com/pageY should take you to what is in pages.site5.com/pageY  how can I do that ?

I create landing pages in order to launch PPC campaigns for my customers. However, I would like to host them all together under a sub-domain of MY website.   For example:  I want that someone who visits www.clientnumber2.com/landingpage could see the landing page and still the same URL www.clientnumber2.com/landingpage, but actually host it myself.  The same for client3, client4, and so on...


I have a command, but I want to get the results into a .txt file I can open. How do I alter my command to allow the results to be put into a text file. I plan to transfer this .txt file to my local desktop.  my command | grep stackoverflow    I have tried:  echo my command | grep stackoverflow > ex.txt  Although nothing comes up in the .txt file.  Thanks.

I often see tutorials online that connect various commands with different symbols. For example:  command1 |  command2 command1 &  command2 command1 || command2     command1 && command2   Others seem to be connecting commands to files:  command1  > file1 command1  >> file1   What are these things? What are they called? What do they do? Are there more of them?    .


My laptop's screen is far too bright at night, even if I set it to minimum brightness. I know that it is capable of being dimmer, because Windows will dim it further if I leave it idle. However, I can't figure out how to dim it lower to minimum on Ubuntu. Is there a way?  I've looked at  question, but it's talking about Windows.

My laptop is Lenovo T400, and my OS is Ubuntu 10.10. I change the brightness of my screen by pressing the FN key and one of the two keys for increasing/decreasing brightness.  The brightness I feel comfortable is between two consecutive levels that are offered. So I wonder if it is possible to fine-tune the screen's brightness?


Let's begin with a sentence such as:     We can't do this any more.   This is the most standard form and grammatically perfect. But I have also seen or heard many times in some informal occasions (maybe that is a fad), esp. in pop lyrics, some sentences like this one      We can't do this no more   or even     Ain't got no money in my pocket   I'm most aware that such a "fad" is grammatically incorrect and definitely unacceptable in formal occasions. But, what about using it in some informal occasions like everyday conversations? Would that be acceptable? and, since I'm not a native speaker, I want to ask: would such usage (in informal occasions of course) make me appear less "alien" to those native speakers? Or,is it that I better not use it in any case? Thanks for any advice.

I have heard many (rather most) people, especially in the USA, saying:      I don't know nothing about it.   Is that correct? I always get a weird feeling hearing this and feel the correct one would be saying:     I don't know anything about it.


I am staying in Paris in a couple of weeks and I booked a day trip to London via EuroStar. Looking around here and the internet I believe I do not need a visa to travel to London from Paris since I will not be staying more than a year. Am I correct on not needing a visa?

Everything I've seen points to no (and I would love that to be true since applying for a visa online costs money) but I'm worried about getting refused due to the length of time I wish to stay, which is 6 months.  I went to university in the UK on a Tier 4 visa, but have never just been a tourist which is what I would like to do now. Since graduating, I have started working but am underwhelmed and would love to travel again. My original plan was Australia but now I would like to see the rest of the UK as well beforehand.  If I arrived with the following, would I be refused entry simply for not applying online?: an approved Australian work & holiday visa, a mini itinerary, bank statements for the last 6 months.


Verified  on desktop. But on mobile web it made me give an up vote, so there's no "click on number".  Are we going to be able to view total votes on mobile using a browser?

It seems we can't view the number of up-votes and down-votes a question has from the mobile site. Can this be added or is there a reason it isn't available?


Let ABC be a triangle. Let B' and C' denotes respectively the reflection of B and C in the internal angle bisectors of angle A. How do I prove that the triangles ABC and AB'C' have same incenter.

The question is as follows if $ABC$ is a triangle, with $AD$ as the internal angle bisector of $\angle A$ with $D$ at $BC$ and $B^{'}, C^{'}$ are reflection of points $B$ and $C$ in $AD$. Show that triangles $ABC$ and $AB^{'}C^{'}$ have the same incentre. This was the exact question language,     Now intuitively here was where I could not satisfy myself, how come two triangles which only shared a vertex $A$ above have the same incentre ?all I could find in this problem was we have $C^{'}B^{'} = CB$,(because notice that here $B$ and $B^{'}$ lie at a same distance from $AD$ as $B^{'}$  is a reflection of $B$ only,same with $C$ and $C^{'}$) which also gives us $BD = DB^{'}$ and $CD = DC^{'}$ , all I claim here could be proved if we join $BB^{'}$ and $CC^{'}$ which pass through $AD$ and is perpendicular to it and also these 2 pair of points($B, B^{'}$) & ($C, C^{'}$) lie equidistantly from $AD$, by which I could say triangle $BDC^{'}$ is congruent to $B^{'}DC$. I didn't find anything more substantial.  So here is my question from the figure can we ever have the incentre of triangle $ABC$ to be the incentre of  $AB^{'}C^{'}$ for incentre we need a centre of a circle inside the triangle which touches all the 3 sides of it which so how come another circle of a different triangle have the same incentre ? Although I could not disprove it concretely it just runs counterintuitive to me, so do I miss something Or did I interpret the question wrongly ?


I am writing an email reply and want to confirm if the punctuation below is correct.  *     In response to your question, if it is available, my answer is “yes!"   *  EDIT: Also, should the exclamation mark be inside the the quotations or after.

Possible Duplicate:             Or is it region specific? I was always taught that when ending a quotation, that punctuation remains inside of the quote.     I think he said, "we should go to the store."   Are you sure he said, "we should go to the store?"   As opposed to:     I think he said, "we should go to the store". Are you sure he said, "we should go to the store"?   This is just an arbitrary example off of the top of my head, and it's hard for me to come up with an example for the second usage because it looks completely wrong to me.   I actually got into a small argument with my girlfriend earlier this year because she uses something similar to the second example, and said that's how she was taught (which is why I ask if it's region-specific.)  Anyway, is there a correct usage for ending a quotation with punctuation?


From The problem statment: What is the monthly payment for a $800,000   mortgage for the first 119 payments that is due in 10 years, has a 25   year amortization, at 5% interest? What is the amount of the 120th   payment?   PV: 800,000 from loan is due in 10 years,  and 25 amortization at 5% then, from here I have  Monthly interest I/Y:   5/12 = 0.42  Amount of payments N:   25*12= 300 payments  Then I have:  N      I/Y        PV        PMT     FV      300     0.42      800K       ?       0   PMT= -4,699.09  Now at payment 119       I paid : -559,192.19 each payment of -4,699.09  and at 120 I will paid: -563,891 and left a balloon payment of 236,108.71 = 800k-563,891  Question: Is it my work correct or I'm missing something? Thanks

What is the monthly payment for a $800,000 mortgage for the first 119   payments that is due in 10 years, has a 25 year amortization, at 5%   interest? What is the amount of the 120th payment?   I use excel to compute the amortization table,    But, I'm still don't understand the question. If I finish the loan at payment 300, for 25 years or I ended at 120 with a full balloon payment.   I ask my professor and he told me: 'If mortgage due in 10 then final payment is a balloon payment including interest and principal'.  Question: I need to know what schedule I suppose to calculate (on excel or any other way that could be easier), and some hint to understand what actually the problem ask.  Thanks!


My friend corrected me that asking "Can I have a ketchup?" instead of "Can I get some ketchup?" It sounds wrong and not native.  I understand that ketchup is not countable, but since it's a fixed size, I thought it'll be okay to say it like that.  Like if you were to order a glass of Coke at a restaurant, which one sounds more native and are there any that sounds grammatically wrong?     Can I have a Coke?    Can I have some Coke?    Can I have a glass of Coke?    Can I have Coke?   And what if you were to pick a can of soda instead of a glass of soda?  And would you say "I want to order a drink" or "I want to order drink"?

I have been reading  (a novel) for the last seven days. I have seen in the novel that the writer used the indefinite article a before a uncountable noun water.      I glanced at Linc again. His grin was still in place, but he rolled   his eyes as if he was amused with his dad.      “Okay, well, thank you. It didn’t take me too long to get settled in   though,” I said, feeling the need to say something. I wasn’t good with   small talk.      “Good. I’m glad you’re ready to dive in. Please, have a seat. Can Linc   get you a water?”   However, I do not think that we can put the indefinite articles (a and an) before uncountable nouns (water, milk, wine). As per my opinion, the author should have said:     “Good. I’m glad you’re ready to dive in. Please, have a seat. Can Linc   get you a glass of water?”      “Good. I’m glad you’re ready to dive in. Please, have a seat. Can Linc   get you a bottle of water?”


We know the computer on Starfleet ships has very advanced AI to interact with the crew, but also it can produce very complex simulations in the holodeck with person-to-AI interaction.  So did Starfleet ever design a fully AI vessel for research / combat?  (I would prefer canon-only answers.)

Computers on board Starfleet vessels are quite primitive compared to on board computers such as . At their best, they can decipher requests such as "Computer, delete that last sentence" and utter things such as "That crewman is no longer on board this vessel". Even real life computers will be capable of this within a decade or so (by some estimates). Even computers such as HAL 9000 are likely to be available within a few decades.  So, in a genre where intelligent computers are abound, why this strange absence? Did the Federation run into some Battlestar-Galactica-like problem with AI in the past and decide to keep on board computers decentralized?  But if that is the case, how can one explain Data and highly intelligent holographic characters? The technology and programming constructs clearly exist, yet Starfleet vessels continue to be manned by hundreds of people standing in front of consoles.


I would like to upgrade my python3 version from 3.2.3 to 3.3.x version. I am using Ubuntu 12.04   Referred this . Is it the same procedure to upgrade the python version?  If so, then what must be run instead of sudo apt-get build-dep python3.4?  I have a doubt in the procedure because it is updating in same version line 3.4.x. Please refer and say so as to avoid further problems.  Edit 1: Also referred this link  but did not help me.

I have downloaded Python 3.3 from the official site but no idea how to install it.   I'm using Ubuntu 12.04


This question ends with is he:     He is seldom absent, is he?     Shouldn't it be isn't he? Please explain.

A couple of days ago, I sat for an English exam. There was a question there that asked for the appropriate question tag for the sentence "He's too weak to walk." I answered "isn't he?" but my teacher claimed that the correct answer should be "is he?" since the sentence expresses a negative meaning. Frankly his explanation made no sense to me.  Is he right? Am I missing something? What should be the appropriate question tag for the sentence He's too weak to walk.?    When we're asked to add question tags in tests, we are expected to add tags that agree with the assertion, for example, It's a great day, isn't it? Question tags that genuinely express doubt whether the sentence is true or not aren't expected.


Can anyone give me full details about what we mean by hyperparameters, and what in the Dirichlet distribution are called hyperparameters? A practice example for the estimation of those parameters would also be useful.

Title says it all.  I have seen both "the hyperparameter of the Dirichlet distribution" and "the parameter of the Dirichlet distribution"  What are the differences?


I have a long object (a leg bone). The object consists of two parts (left and right) which are divided by a non-manifold plane (zero thickness). I would like to ask if there is any way to paint the right part with different color than the left part without "cutting" the object by Boolean modifier? Thank you

How do you add more than one material to a mesh?   I have tried adding two materials to the object, and then assigning one of the materials to a vertex-group, but I could not find a place to assign it.  I am making a striped bouncy ball that I want to deform, so adding a different material by separating the mesh into different objects would not be ideal.


Everytime I download Ubuntu onto my mac laptop, it is downloaded as an .iso file.  I cannot open the file because it tells me in Launchpad:   hdiutil: mount failed - No such file or directory

I've recently taken up a position in an all Mac workshop - We have Intel based Apple machines. Can I dual boot Ubuntu on my machine, if so how?


I need to execute a command once a usb storage media is inserted. But I don't want to identify the device by the device file, e.g /dev/sdcX.  So I can't use filters like KERNEL=="sd?"  Is there any other identifier I could use, maybe the serial number of the USB storage media? (I'm not even sure how to read them with udev)

I have a USB key that contains my keepass2 password database and I'd like to perform some actions when it is plugged into my computer, namely:   Auto-mount it to some specific location When the mounting is done properly, launching keepass2 on the password database file   Simple tasks I guess, but I can't find how to do that.  I'm using Ubuntu 12.10, and it auto-mounts the device as a "media usb-key" and tries to open the images on it (even though there are none).  What is the best way to do that and to disable the ubuntu auto-mounting (so it doesn't conflict) ?


Note:  already exists, albeit being for C#.  Let's suppose my code looks like the following:  class SomeClass:      def __init__(self):          pass      def do(self):         print("a")  class SomeOtherClass:      def __init__(self):          pass      def do(self):         print("b")  class B:      def __init__(self):          self.SomeClass = SomeClass()            self.SomeOtherClass = SomeOtherClass()  def __main__():     myclass = B()     desired_class = str(input("The method of which class do you want to execute? "))     myclass.desired_class.do()    I will not know at built-time what method of SomeClass will be called. If-then-else is also not very neat if you have 200 methods and no just 2 to choose from.  How is this done most efficiently in python?  Note: The method will always be an existing method of SomeClass.

What is the best way to go about calling a function given a string with the function's name in a Python program.  For example, let's say that I have a module foo, and I have a string whose content is "bar". What is the best way to call foo.bar()?  I need to get the return value of the function, which is why I don't just use eval. I figured out how to do it by using eval to define a temp function that returns the result of that function call, but I'm hoping that there is a more elegant way to do this.


I have followed a thing for how to get bots to move. I chose a gamemode that bots support(PL) and it has a navmesh. The only thing is they stand still like they don't have  a navmesh. PLease help.

I know how to spawn bots with the command tf_bot_add, but when I spawn the bots, they just stand there. How do I get them moving?


My problem states the following:  A topological space $X$ is connected if and only if there are no nonempty proper subsets of $X$ that are both open and closed in $X$.  Here is my proof:  Since the theorem is if and only if statement, we must prove it in both directions.  ($\Rightarrow$) Let $X$ be a connected topological space and for the sake of contradiction, suppose $U$ is an open and closed proper subset of $X$. Because $U$ is open, nonempty and proper subset of $X$, it must be the case that $X-U$ is closed and likewise nonempty and proper subset of $X$; because $U$ is closed, it follows that $X-U$ is open. But now we have that $U \cup (X-U) = X$, $U \cap (X-U) = \emptyset$ and $U$, $X-U$ are open, nonempty subsets of $X$, which means that $X$ is not connected. This is a contradiction, because we assumed $X$ to be connected; therefore, it must be the case that if $X$ is connected, then there are no nonempty proper subsets of $X$ that are both open and closed in $X$.  ($\Leftarrow$) We will prove this direction by contrapositive method.   Let $X$ be a topological space and suppose that $A$ is a nonempty proper subset of $X$ that is both open and closed in $X$. But since $A$ is open, it must be the case that the complement of $A$, i.e. $X-A$ is closed; similarly, since $A$ is closed, $X-A$ must be open. Also, since $A$ is a nonempty proper subset of $X$, it follows that so is $X-A$. Observe, that $A \cap (X-A) = \emptyset$, and $A \cup (X-A) = X$. So now we have that both, $A$ and $X-A$ are open nonempty proper subsets of $X$ that are disjoint and $A \cup (X-A) = X$. Hence, it must be the case that $X$ is not connected.  My question is: Both directions look almost identical, is this ok, or shall I work on this in some another way?

I'm trying to understand this proof that:  $M$ connected $\iff$ $M$ and $\emptyset$ are the only subsets of $M$ open and closed at the same time  Which is:  If $M=A\cup B$ is a separation, then $A$ and $B$ are open and closed. Recriprocally, if $A\subset M$ is open and closed, then $M = A\cup(M-A)$. What? I know that if $M=A\cup B$ is a separation, $A$ and $B$ are both open. But why closed? Also, the 'recriprocally' part is totally nonsense to me. Anybody could help?  Also, there's another proof, which states: $M$ and $\emptyset$ are the only subsets of $M$ at the same time closed and open $\iff$ if $X\subset M$ has empty boundary, theb $X=M$ or $X=\emptyset$  which is proved as the following:  given $X\subset M$, we know the condition $X\cap \partial X = \emptyset$ implies $X$ is open, while the condition $\partial X \subset X$ implies $X$ is closed. Then, $X$ is open and closed $\iff$ $\partial X = X\cap \partial X = \emptyset$, this show $\iff$ for the theorem above.  First of all, I think that the condition $X$ has boundary empty implies that $X\cap \partial X$ is empty, but who said anything about $\partial X\subset X$? Also, where's the $\rightarrow$ of this proof? I can only see $\leftarrow$


The six character requirement for edits makes little sense.  I've come across an answer with a typo of one character but without correction, the code is nonetheless redundant.   e.g.   (see "Weedkly" that should read "Weekly").  Where is the logic in assuming that a one character mistake is less incorrect or edit-worthy than a six character mistake?  Posting a comment to the said question and tossing a coin as to whether the user will correct their post seems less efficient than allowing unrestricted user-wide editing.  I appreciate that you're perhaps trying to mitigate the moderating queues for edits. Implementing a lower tier of moderators exclusively for spelling/grammatical errors (i.e., for non-expert coders) would allow you to assemble a body of volunteer moderators and thereby allow 1 character editing.

Possible Duplicate:          I was reviewing a question on stackoverflow today.  According to the yellow box on the right side of the window I am encouraged to correct minor grammatical or spelling errors.  So I attempted to do this and was unable to save it.  In this case the OP mispelled maybe.  Why is this restriction in place?  Seems kinda silly to me.


I was just wondering, is there a verb for the use of uptalk (using an inflection at the end of a statement)? So, something like this:     I've been on several walks recentLY. (inflection at the end of a statement, as if it were a question)   (Some would add a question mark after such a statement, to signal the stress, but this is non-standard and confusing except when the sentence is a declarative question.)   Is there a word to express the using of such a style? (i.e. a word that can fill this blank responding to the previous sentence:)     Stop ______!   I've already got "sounding unsure of yourself" or "inflecting your sentences", but it doesn't sound brief (or good enough). When I searched online I couldn't find anything, I just found blogposts that were just trying to convey the message "stop being indecisive".

I have been wondering about the  used in almost every sentence, by especially young Americans.    What is the purpose/intention of rising pitch except in questions? Is it friendly and polite, or condescending? Is it proper to be used in presentation and teaching and other professional occasions?   For example: In , starting around 0:40, when Amy Chua introduced herself.


can somebody please explain to me how is this possible?  df -h Filesystem      Size  Used Avail Use% Mounted on /dev/md2        204G  170G   24G  88% /  du -ah / | sort -rh | head -20 121G    / 88G /var   So, essentially my / folder is 121GB large (running all as the root user), but my hard drive is 170GB full?  Running the Ubuntu 12.04.

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.


What is the largest perfect square that divides $$2014^3-2013^3+2012^3-2011^3+\cdots+2^3-1^3$$


There is a scenario where I need to display Date, Hours and Minutes left for the subscriber's subscription to end. I am able to implement this using Ampscript in my email and also mail is triggered through Marketing Cloud. The only challenge is every time when the user sees the email, same time is shown as that of when the email was triggered. Is there a way to keep updating the time whenever the user sees the email?

I have a Javascript file written and saved in Cloud Page. Now,I want to refer this Javascript file from Cloud page inside my email in Content Builder. The reason why I am following this approach is because content builder removes Javascript statements mentioned implicitly inside emails. Any help would be much appreciated


My itinerary is as described below:  22nd December - Land in Paris ( 9 am)  26th December - Leave from Paris in evening via Bus (5 Days)  27th December - Arrive at Zurich in Morning, Stay till 1st January 3.30pm ( 5.5 days)  1st Jan - Take a flight to Paris from Zurich in afternoon (3.30 pm).  1st Jan - Leave for India from Paris Airport.  Which Embassy should I apply Visa for?

I'm planning to go to Germany on Sept 6-8, then Netherlands on Sept 8-11 and exit Switzerland on Sept 11-14.  My question is:  Which embassy do I need to apply for the Schengen visa? The number of days are the same for Netherlands and Switzerland, but I'm planning to apply in Netherlands since it will be my second point of entry.


I am traveling to France. Booked trip through Delta. First leg is from home airport US, to JFK on Delta, second then is to France via Air France under Delta. So, when I arrive at JFK, will I have to retrieve and recheck my bags when I get to the international terminal or do they check it through to my final destination...and then coming home France to Detroit, Detroit to home airport. Thanks.

I am flying from Orange County, California to San Francisco, California and then on to Seoul, South Korea. If I check a bag will I have to pick it up in San Francisco and re-check it and go through security or customs for the international flight?  Everything I am reading leads me to believe that it's only necessary to re-check baggage and go through security and/or customs when you are first arriving into a country. However, since my first leg is staying within the United States I assume the airline will transfer my bag to the next flight and I can just go straight to the gate for my international flight?  Both legs of the flight are through the same airline (United Airlines) and there are only the two legs: OC -> SF, then SF -> Seoul.


I want to use the Fisher Scoring Algorithm in Newton-Raphson method.  I(theta_m) in above that calculated at each iteration, has to be positive definite? Is it possible this matrix be indefinite?

I`m using the Newton-Raphson method for obtaining MLE for parameters for maximizing my objective function. At each iteration, I want to check that is the Hessian matrix negative definite or not and I see the Hessian matrix is not negative definite at some iterations. So, I want to use the Fisher scoring algorithm ( of derivation) In this situation, the Fisher information matrix is indefinite!! Is it possible? What are the reasons for this? Are the second-order derivatives wrong? Or are values of expectations incorrect?


I have a canon 700D camera, and an 18-55mm lens.  I would like to buy another lens, but I am confused.   I like to photograph celebrations, marriage parties, and casual family functions  Please suggest one lens for me.  Antony Manoj.

This is somewhat a follow-up to my . I have browsed through quite a lot of sites including this one for user opinions & reviews of different Canon lenses, but haven't found a comprehensive answer to the possible upgrade paths from the kit lens, particularly since I don't have a specific usage scenario in mind. Here are a few that I have found that answer the question partially:   (Quite old)   (for Pentax though)     (more about the cameras)        For this reason, I thought it would be useful to have a list of sub-$1000 upgrade lenses for the kit lens for APS-C format DSLRs (like the 550D, 60D, 7D etc), as a lot of people are upgrading to DSLRs nowadays. The key points that I seek are:   Pros\cons compared to the kit lens Price Scenarios the lens is suitable for   Keep in mind that it is primarily for APS-C cameras, so, EF lenses meant primarily for the full frame cameras would end up with the magnification factor of 1.6x. Also, this is focused towards hobbyists & amateurs for which reason I've added the sub-$1000 bit.  P.S. This question might be more suited for a wiki like article (albeit with user opinions included)


For a random variable $X \sim f(x)$, the $n$'th moment is defined to be $E_f[X^n]$. But for a multivariate distribution, $X$ is a vector so this definition doesn't make sense since you can't raise a vector to power.  How are moments defined for distributions over vector spaces?  My suspicion is they involve Kronecker products: $$E_f\left[X \otimes X \otimes \cdots \otimes X\right]$$ since the first and second moments of a multivariate Gaussian are $\mathbf{\mu}$ and $\mathbf{\Sigma}$.

I am self-learning on linear model theory right now, and one thing I find surprising is that although $\mathbb{E}[\mathbf{Y}]$ is defined for a random vector $\mathbf{Y} = \begin{bmatrix} y_1 \\ y_2 \\ \vdots \\ y_n\end{bmatrix}$, there is no mention of further moments besides the covariance matrix.  Google searching hasn't turned up much. Are $k$th (raw) moments of $\mathbf{Y}$ considered, or is there a different idea I don't know about?  I am learning from the text  (the TOC starts in p. 17 of the linked file). By "considered," what I mean is is there such a thing as $\mathbb{E}\left[\mathbf{Y}^k\right]$, and if so, how would such a concept be defined? The book I have only covers the first raw moment, and I find it a bit strange that there is no mention of how to define $\mathbb{E}\left[\mathbf{Y}^k\right]$ given my experience in univariate probability, nor do I have the expertise to define it.  Furthermore, if $\mathbb{E}\left[\mathbf{Y}^k\right]$ isn't defined, is there perhaps a related concept that I don't know about that is used instead?


How long can you store uncooked cut fries?  Tried to make some other day, didn't finish. Had quite a bit left over.....am currently storing them in water in refrigerator.  How long will they be safe to fry and eat? Or, can they?  Would estimate it's been at least 4-5 days.  Thanks

How do I know if a given food or ingredient I have is still good, or if I should discard it?  How can I best preserve a food or ingredient?     This broad question is intended as a "general reference" question to quickly answer many how long will food keep for? questions. Please feel free to edit this question to expand and clarify as needed.


I have to prove the following statement.     $$1+\cos{2\pi\over5}+\cos{4\pi\over5}+\cos{6\pi\over5}+\cos{8\pi\over5}=0$$   I have tried to use the sum of angles formula for cosine, but didn't get to a point where I'd be able to show that it is equal to $0$.

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 added changes and made a commit locally  git add . git commit -m "my changes..."   Realised I had made a mistake in my code so undid the commit  git reset --soft HEAD~1   Then I entered this  git checkout HEAD .   instead of this  git reset HEAD .   So I've dropped a clanger and lost my changes :(  Is there any way to get back the code? Undo the checkout? or is it still in the commit somewhere?  UPDATE: Think I might have an answer!  Found this -   Buried in one of the answers was "git reflog" - which I have never heard of.  Then found this - .  So currently making a copy of my folder before doing anything else...

Is it possible to undo the changes caused by the following command? If so, how?  git reset --hard HEAD~1


I tried to get extras from the intent in recyclerView and display it in detail but when I tried it there was a      java.lang.NullPointerException error: Attempt to invoke the virtual   method 'java.lang.String java.lang.Object.toString ()' on a null   object reference   public class NotifDetailAct extends AppCompatActivity {  DatabaseReference reference; TextView xdeskripsi;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_notif_detail);      xdeskripsi = (TextView) findViewById(R.id.xdeskripsi);      Bundle bundle = getIntent().getExtras();     final String tittle_baru = bundle.getString("tittle");       reference = FirebaseDatabase.getInstance().getReference().child("notif").child(tittle_baru);     reference.addListenerForSingleValueEvent(new ValueEventListener() {         @Override         public void onDataChange(DataSnapshot dataSnapshot) {             xdeskripsi.setText(dataSnapshot.child("isi_notif").getValue().toString());         }          @Override         public void onCancelled(DatabaseError databaseError) {          }     }); }   }     java.lang.NullPointerException error: Attempt to invoke the virtual   method 'java.lang.String java.lang.Object.toString ()' on a null   object reference

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


The code for my TextBoxAreaFor<> text area (for some reason) puts the cursor at the end of the text area and not at the start like a TextBoxFor<> does. How do I get the cursor to be placed at correct position i.e. At beginning of text area?
         @Html.LabelFor(model => model.IncidentDescription, new { @class = "control-label col-md-2" })
             @Html.TextAreaFor(model => model.IncidentDescription, new { @class = "control-label col-md-1" })             @Html.ValidationMessageFor(model => model.IncidentDescription)

How do you set the cursor position in a text field using jQuery?  I've got a text field with content, and I want the users cursor to be positioned at a certain offset when they focus on the field.  The code should look kind of like this:  $('#input').focus(function() {   $(this).setCursorPosition(4); });   What would the implementation of that setCursorPosition function look like?  If you had a text field with the content abcdefg, this call would result in the cursor being positioned as follows: abcd**|**efg.  Java has a similar function, setCaretPosition.  Does a similar method exist for javascript?  Update: I modified CMS's code to work with jQuery as follows:  new function($) {   $.fn.setCursorPosition = function(pos) {     if (this.setSelectionRange) {       this.setSelectionRange(pos, pos);     } else if (this.createTextRange) {       var range = this.createTextRange();       range.collapse(true);       if(pos < 0) {         pos = $(this).val().length + pos;       }       range.moveEnd('character', pos);       range.moveStart('character', pos);       range.select();     }   } }(jQuery);


It's a 2011 MacBook pro and the a and c keys are not working on both the built-in keyboard and the usb keyboard.   Because of this i can't bypass the firmware login screen.  Now the weird thing is that that cmd + a works (select all) so the key is being recognized, but a by itself doesn't.   Any ideas?

This is an attempt to write a canonical QA for this issue, as per the Meta post:   I expect it to be periodically edited with the goal of becoming a comprehensive information resource.  I have a MacBook Pro that has a key(Shift, Return,   Command, P, etc.) that doesn’t respond when pressed or is stuck in the down position.    It's possible that my favorite beverage was spilled (or some other liquid damage).  It's also possible that I have no idea what happened.  It was working yesterday and suddenly today it's no longer working.  Is there any way to bypass or remap the key?  Can I  have the system ignore it completely?  (This question can also apply to external USB keyboards or the Bluetooth keyboards)


What do you call a person who always wanted to get his expected results?  I'm looking for a trait of a person that means who always wanted to get his expected results.  For example: a person ordered a soup and he feels upset when the taste doesn't satisfy him because he is expecting some taste in the soup he ordered.

I'm looking for a word that means     someone (especially a boss) who is not pleased (with your work, attitude etc.) no matter how hard you try.


I would like to ask if someone could help me with solving the following task.  The middle triangle is KLM (hatched). Prove that $|AK| = |KL| = 3|LB_1|$.   Thank you in advance.

I would like to ask if someone could help me with solving the following task.  Find the area ratio between ABC and the hatched triangle.    Thank you in advance.


In Star Trek, basically everyone is a human with facial make-up; are there any instances where character comment on this and attempt at an in-universe explanation of this within this franchise?  Note, I am not asking what the in-universe reason is, rather whether, in-universe, characters have made comment on the abundance of humanoids and attempted to explain it.  Note:formerly this question was for Star Trek and Star Wars, which was too broad.   Removed SW because most of the answers and the accepted one related to Star Trek.

The vast majority of intelligent species in the Star Trek universe are bipedal, humanoid creatures.  From the lot I've seen of TOS, TNG, DS9, Voyager, Enterprise, and the movies, it seems that this coincidence goes largely unquestioned.  Metaknowledge grants that it is much easier to have human actors portray human-like beings, and so this was probably done due to budgetary/technological limitations.  However, I'm wondering if an in-universe reason for this was ever given or explored?


A textbook I'm reading states the set $A = \{f \in C^1[0,1]: \|f\|_\infty + \|f'\|_\infty \leq \gamma\}$ is compact in $C[0,1]$ with the sup norm. Here, $\gamma$ is a positive constant. Well, by Arzela Ascoli, as this set is equicontinuous and uniformly bounded in $C[0,1]$, any sequence in this set has a subsequence which converges uniformly to a function in $C[0,1]$. What I'm having trouble proving is that this limit is in $A = \{f \in C^1[0,1]: \|f\|_\infty + \|f'\|_\infty \leq \gamma\}$. I don't see why this limit is necessarily differentiable in the first place. If $f_n \in A$ for all $n$ and $\|f_n - f\|_\infty \rightarrow 0$, then for $f$ to belong to $A$, it would be enough if $\{f_n'\}$ was a Cauchy sequence. (Then $f'$ must necessarily exist and be the limit of this sequence) - but again, I don't think this is true.

Here we use infinity norm as metrics for $C[0,1]$. The professor claims that this set is compact. I can show this set is relative compact by Arzela Ascoli, i.e., for each subsequence there is a further sub-subsequence that uniformly converges to a continuous function on $[0,1]$. But it is not intuitive to me why this set is compact, i.e. the limiting function also satisfies $|f'|_\infty \le M$. Is it true that $A$ is close and therefore compact?


Is there a word for a second word which is contained in the first word, as in, for example, the word end in the word friend?

Is there a term for a word that occurs unbroken within another word? For example, the word "fun" in "funeral", or "drag" in "hydragog".  The closest thing I could find from my search was the term "", which refers to a word that contains the letters of its synonym, in the correct order (though not necessarily consecutively).  I am currently using "substring" as a substitute in my essay. Unfortunately, "substring" applies to any selection of consecutive characters from the containing word, and doesn't convey the fact that the subset is a complete English word.  I have tagged this , but I would appreciate single words as well. I will have to use the term quite often, so the less awkward it is, the better.


Find $a$ inverse modulo 30, $1\le a \le 30$. For each a you find, find the inverse of each a that have inverse modulo 30  a={1,7,11,13,17,19,23,29}  They got a by the fact that relative primes are inverses. I was wondering if this rule also applied if $a \ge 30$?  Find the inverse of each of the integers in a that have an inverse modulo 30  Not really sure how to do this part

For example: $$7x \equiv 1 \pmod{31} $$ In this example, the modular inverse of $7$ with respect to $31$ is $9$. How can we find out that $9$? What are the steps that I need to do? Update If I have a general modulo equation: $$5x + 1 \equiv 2 \pmod{6}$$ What is the fastest way to solve it? My initial thought was: $$5x + 1 \equiv 2 \pmod{6}$$ $$\Leftrightarrow 5x + 1 - 1\equiv 2 - 1 \pmod{6}$$ $$\Leftrightarrow 5x \equiv 1 \pmod{6}$$ Then solve for the inverse of $5$ modulo 6. Is it a right approach? Thanks.


If try to draw anything inside a shape it gets selected instead, the cursor turns into hand from pen. So basically how can you draw shape on/inside another shape?

When drawing using draw tool, if I hover over a shape or image it turns into the hand tool and then I can't draw. How do I fix this?


Problem: Not able to update swing component from another class.  Objective: When user clicks the update button, the text in "nameLabel" will change to "John Doe".  I attempted the solutions from stackoverflow regarding this issue but had no success.  Here is a very simple example, not sure what I'm doing wrong.  GUI.java  package TestGUI.TestGUI;  import java.awt.BorderLayout;  import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel;  public class GUI {      JLabel nameLabel;     JButton updateButton;     JFrame frame;     JPanel panel;      public void display() {          frame = new JFrame();         panel = new JPanel(new BorderLayout());          frame.setTitle("BlackJack Game");         frame.setVisible(true);         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);         frame.add(panel);           nameLabel = new JLabel("No Name");         updateButton = new JButton("Update");          panel.add(nameLabel,  BorderLayout.NORTH);         panel.add(updateButton,  BorderLayout.SOUTH);          updateButton.addActionListener(new EventListener());     }      public void setNameLabel(String name) {         nameLabel.setText(name);     } }   EventListener.java  package TestGUI.TestGUI;  import java.awt.event.ActionEvent; import java.awt.event.ActionListener;  public class EventListener implements ActionListener {      //private Card card;     private GUI gui;      public EventListener(GUI gui) {         this.gui = gui;     }      public EventListener() {         // TODO Auto-generated constructor stub     }      public void actionPerformed(ActionEvent actionEvent) {          String actionCommand = actionEvent.getActionCommand();          if(actionCommand.equals("Update")) {             gui.setNameLabel("John Doe");         }      } }   App.java  package TestGUI.TestGUI;  public class App  {     public static void main( String[] args )     {         GUI gui = new GUI();          gui.display();     } }   The following error is produced, when the "update" button is clicked.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I've somewhat recently started seeing a red banner on top of every page, stating: [Foo] Stack Exchange requires external JavaScript from another domain, which is blocked or failed to load. Retry using another source.  Following the "Retry using another source" link fixes it, but only temporarily.  Exactly what domain does it attempt to load, such that failing to do so results in this message? What does the "Retry using another source" link do? The uri suggests it involves jquery and cookies, but it immediately redirects to the main site when I hit the link. Assuming it is setting a cookie, what cookie does it set?  I'm sure that given enough time, I could reverse engineer the various scripts on the page and figure out what exactly it's complaining about, but might it be possible to instead include that information in the error message?

I work behind an really annoying firewall, and I just want the net admin to add all the SE websites to the whitelist. Right now I've lost access to Stack Overflow's authentication, but not Meta's... so I have to come here before I log in there.  It's driving me nuts. Basically I just want to add an exclusion rule for all SE domains; not only the website domains, but also the content domains such as gravatar.com, quantserve.com, the domain that holds static content, etc...


I have a program called /usr/bin/myprogram.x  In one shell window I did something like  cd /run001/ myprogram.x & cd /run/009/ my program.x & cd /run/234/ myprogram.x &   I kicked off a total of around 10 jobs, all under various directories, is there a way to find those run directories ?  If I do a ps -ef | grep myprogram.x it reports them all as /usr/bin/myprogram.x however I am looking for the directory each was kicked off under.  Is there a way to find that?

What command(s) can one use to find out the current working directory (CWD) of a running process? These would be commands you could use externally from the process.


We define $a_1=1$ and $a_{n+1}=\dfrac 12\left(a_n+\dfrac{2}{a_n}\right)$.  I'd like to show that this sequence converges (and $a_n\to\sqrt{2}$). So, I wanted to prove that $a_n$ is monotonic and bounded. I thought that $a_n<\sqrt{2}$, but I was wrong. Maybe this sequence isn't even monotonic.  What do you think?  I already know that if the limit exists, say $l$, then $l=\dfrac{1}{2}\left(l+\dfrac{2}{l}\right)$. But we still need to prove that $a_n$ converges.  Thanks.

We define $a_1=1$ and $a_{n+1}=\dfrac{1}{2}\left(a_n+\dfrac{2}{a_n}\right)$.  I want to prove that $a_n$ converges. But first I'd like to show that $a_n<\sqrt{2}$ for every $n\in\mathbb{N}$.  I try to use induction. For a fixed $n$, I suppose that $a_n<\sqrt{2}$.  Any hint to prove that $a_{n+1}=\dfrac{1}{2}\left(a_n+\dfrac{2}{a_n}\right)<\sqrt{2}$?  Thanks.


Let $R$ be bring, and $M$ be module over $R$. Then, we usually define krill dimension of $M$ as $dim(A/ann(M))$, where $dim()$ is krull dimension of ring. But Is this compatible with definition of krill dimension of $R$? That is, does $dim(A/ann(A))＝dimR$ always hold ? I think $ann(A)$ is not always $0$. Where am I missing? Thank you in advance.

Let $R$ be a commutative ring with $1$. We know that the Krull dimension of $R$ is by definition the length of the longest chain of prime ideals of $R$.   Now if $M$ is a  $R$-module, the  is by definition $\dim(M):=\dim(R/\mathrm{Ann}_R(M))$. Since every ideal $I$ of $R$ is also a $R$-module, the Krull dimension of $I$ is $\dim(I)=\dim(R/\mathrm{Ann}_R(I))$.  However, in the literature, the Krull dimension of an ideal is $\dim(I):=\dim(R/I)$.   Are the two definitions equivalent?


How can I open a KML Network Link in QGIS? I have googled this question and searched for  on Stack Exchange. I am not asking how to open a KMZ in QGIS. I don't see any references to trying to open a KML Network Link in QGIS.

If it is possible to open and visualize a KML Network Link in QGIS, then what are the steps involved? KML Network Links are described at  and at :  In the most generic sense, a KML file with a network link acts as a gateway into the content on your server. Your users download your KML file just once, but they will always see the most updated content, even if you updated it after they download your KML.  A KML file with a network link can be embedded within a KMZ file.


I keep getting grainy renders. I used denoising and my samples are at 500. Any idea on how to fix this?

I know that this question is a bit old or maybe overdone, but I'm running the latest edition of Blender and when I use the Cycles engine I get really fuzzy results and I can't find a simple, non-compromising solution to the quality.  I don't know exactly what I'm doing wrong here, but I'm sure others share my frustration.  Leaving everything in default settings, I started a new project and switched to the Cycles render.  I duplicated the cube and set colors for two Diffuse BSDF shaders, then went ahead and made walls and a floor all sharing the same diffuse shader.  I made two windows to emit blue light.  The screenshot has gaps between the walls because of the setup:  I'm aware that it's considered very incomplete and many have come to terms with some amount of noise, but is this normal?  Furthermore, with default settings or not, I can't change the amount of noise produced.  Supposedly, using "progressively refine" in the rendering tab should make it refine itself indefinitely, however Cycles only counts to 10 refines and then stops, creating a render which is a pixel-perfect match of the ordinary rendering method when it's completed.  I understand that there are tricks that can be used to reduce noise, but at the cost of extra processing time and usually small quality conflicts, like blurring.  My question essentially boils down to is this Cycles' current limit?


Let $A$ be a $2\times 2$ stochastic matrix $$A=\left(  \begin{array}{cc}  1-a & a  \\   b &   1-b\\  \end{array}\right). $$   Then A is a second order transition probability matrix of a DTMC, i.e. there is a DTMC with probability matrix P such that $P^{2}=A$ iff $a+b\leq 1$.   Attempt. The desired property holds iff $$A=\left(  \begin{array}{cc}  1-a & a  \\   b &   1-b\\  \end{array}\right) = \left(  \begin{array}{cc}  1-p & p  \\   q &   1-q\\  \end{array}\right)^2 $$ for some $p,~q\in [0,1]$, that is $a=2p-pq-p^2,~b=2q-pq-q^2$ for some $p,~q\in [0,1]$. I am not sure how this leads to the equivalent desired condition $a+b\leq 1$.  Thank you in advance.

Show that:     A 2 x 2 stochastic matrix is two-step transition matrix of a Markov chain if and only if the sum of its principal diagonal terms is greater than or equal to $1$.


A point P satisfies following condition  : The straight line passing through P and dividing the area of the square  by 1:3 does not exist.  Can we know the locus of P and the area of the locus ?  I think it has to do with logarithm function..

There is a square $Q$ consisting of $(0,0), (2,0), (0,2), (2,2)$. A point $P$ satisfies following condition: The straight line passing through $P$ and dividing the area of square $Q$ in the ratio $1:3$ does not exist.  Can we know the locus of $P$ and the area of the locus?


I am planning to purchase a home and all calculations and the banks say principal, interest, property tax, plus mortgage insurance will be close to $1000 per month.  The calculator show that if I increase my down payment by $10,000, then my monthly payment goes down by $200 per month. Based on that, if I suddenly were to come into $10,000, and apply that to the home loan, would the monthly payment similarly reduce my monthly payment by $200 per month. Over time, would the monthly payment amount slowly reach $0 per month?

I bought a home worth 200,000 paid 20% down, my interest rate is 4%, 30 yr fixed Remaining Loan 160,000. Initially, lets say I pay around 1000 USD (200 toward my principal and 800 towards my interest).(May not be accurate numbers) Now the balance left on my mortgage is 159,000.   If I pay additional 1000 USD towards my principal after paying my balance due this month, Starting next month when I have make my mortgage payment, would I be paying interest on 159,000 or 158,000.   I realized through internet that the additional payments would only cut the down the 30yr term. That is, instead of paying for 30 years, I might be paying for 29 years 11 months. But there would no change in the interest calculation.   Is that true? Appreciate your thoughts in advance.


why is possible to approximate E[gi^2] with E[gt^2]? by the time we go to the t timestamp, we've already made weight updates, which mean gradients should be different as they are taken from different points in parameter space?  I guess we get error term(zeta) by making same approximation but are we really getting rid of that by doing the so-called bias correction, I don't think so

I'm reading  about the Adam optimizer and went up until the bias-correction section; in the paper they estimate the bias of the moving average of the squared gradient. These are the equations they use:    Where $v_{t}$ is the moving average of gradient squared, $g_{i}$ is gradient at the $i^{th}$ iteration and $\beta_{2}$ is a moving average parameter.  I don't understand how they make any of these transitions from the first row to the second and on to the third one. Could someone explain what rules are allowing them to do so ?


I can't log into any Minecraft servers at all, not even locally hosted ones.   The error code I get is: java.net.UnknownHostException: session.minecraft.net. A tweet from a worker at Mojang told people that you could just flush your DNS, which I did. That didn't quite work, so I'm wondering if there are any other solutions out there?   I'm not quite sure what other information I have to give. I know that it's not just something with me because I know a lot of my friends also get this error once they try to log into a server, so it would be weird if all of our ISPs just cut us off.

I can't play online. I can only play solo. I have bought Minecraft so it should work fine, but, when I try to connect to a server, it says:  Internal client error: java.net.UnknownHostException: session.minecraft.net   I have tried over 20 different servers and it says the same thing for every single one.   Note: These are not Hamachi servers. I'm attempting a direct connection.


What color should a deletion confirmation message be?  This is related to the question , but different because this question asks about a passive confirmation message and not the active delete button.  One might say green, the typical success color, but the delete button was red and it looks weird. Making the message red, because you just deleted something, also makes no sense because red is supposed to be for errors.  In my specific case it's about rejecting or accepting proposals. The options are:   (success)   (danger)   (warning)   (info)  Making rejected bold puts more emphasis on the difference between rejected and accepted. The text could also be changed to "You have successfully rejected the proposal," which also puts more emphasis on the actual action regardless of the color.  Using no color, a grey background with black text, looks weird. It doesn't look like a notification anymore at all, so I don't really consider it an option.  Finally someone suggested having no message at all, since the proposal will be deleted from the list of proposals. That deletion in itself should be enough feedback, according to that person. I personally disagree, though. It feels weird.  Overall, I lean towards green or blue (success or info). Red messages should be a failure of some kind, and the yellow warning also makes me feel like there is additional action I should take. Green doesn't look like a rejection (the reject button is red, the approve button is green) and blue also feels off for some reason.  Which option should be used?

Designing an interface for a CMS (Content Management System), I stumbled upon a paradox and I'm a bit confused about what to do and why to do it..  Context  Before deleting an album, the user is asked to confirm the action.  Green "Yes"    Red "Yes"    Which option is more intuitive for the user?


class User:      def __init__(self, username, mail, date_of_birth, gender, password):         self.username = username         self.mail = mail         self.date_of_birth = date_of_birth         self.gender = gender         self.password = password      def get_username(self):         return self.username      def get_mail(self):         return self.mail      def get_date_of_birth(self):         return self.date_of_birth     def get_gender(self):         return self.gender      def get_password(self):         self.password    Matt = User("Matterson", "ville@gmail.com", 15.08.1999, "Password987")  Hi, this is my code but the date is invalid syntax, how do i write the date as a parameter?

I've got a huge list of date-times like this as strings:  Jun 1 2005  1:33PM Aug 28 1999 12:00AM   I'm going to be shoving these back into proper datetime fields in a database so I need to magic them into real datetime objects.   This is going through Django's ORM so I can't use SQL to do the conversion on insert.


I have this code in a var.  <html>      <head>         .         .         anything         .         .     </head>      <body anything="">         content     </body>  </html>   or  <html>      <head>         .         .         anything         .         .     </head>      <body>         content     </body>  </html>   result should be  content

I am looking for a regex statement that will let me extract the HTML content from just between the body tags from a XHTML document.  The XHTML that I need to parse will be very simple files, I do not have to worry about JavaScript content or <![CDATA[ tags, for example.  Below is the expected structure of the HTML file is that I have to parse. Since I know exactly all of the content of the HTML files that I am going to have to work with, this HTML snippet pretty much covers my entire use case. If I can get a regex to extract the body of this example, I'll be happy.  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">         <title>     </title>
       Example paragraph content

       &nbsp;

       &nbsp;

Header 1
       Conceptually, I've been trying to build a regex string that matches everything BUT the inner body content. With this, I would use the C# Regex.Split() method to obtain the body content. I thought this regex:  ((.|\n)*)|(((*|\n)*)   ...would do the trick, but it doesn't seem to work at all with my test content in RegexBuddy.


I have searched about this show and I found it somewhere but I lost it. The show is about some teenagers that start developing alien powers (one British that attended a private school with red uniforms and blonde/red hair, one was Australian, I believe his name was Adam, and one girl, I believe, black). They traveled in pods and hid them in the greenhouse and there is also a beach scene, where they go for the pods and can sleep and travel inside of them.

There was a film from the 80s in which young people can teleport anywhere they can think of.   These guys are recruited to do studies with, maybe by the government or a secret company which wants the take advantage of their abilities.   I saw it on cable TV around 1990-1997.   Any clues?


Last night I wiped and rooted my HTC One Mini and lost a few photos. Is there any way to get them back?

I just deleted a file on my Nexus S that I really need back. (It was actually part of an app using a sqlite database that did a drop table when upgrading to a new version.)  Presumably I need to root the phone first (which I hear is easy on Nexus phones) but am I in a catch-22 here? Namely, does rooting the phone mean wiping/overwriting the partition where the data lives?  If not, what do you recommend for data recovery tools? Presumably the file was just unlinked and not actively overwritten (per usual when "deleting" a file) so technically the data must be there...


I have a computer that has no operating system.  I am currently downloading ubuntu to a memory stick in a usb port, later, I will try to upload it onto my computer.  Am I missing anything here?

I would like to see a full how-to guide on how to install Ubuntu.


This might seem like an odd question but I am really wondering. Up to now I used my trekking bike to commute to work and I never had any issues to leave it in the bicycle floor parking rack due to its factory default kick stand.  However I just bought a new mountain bike (XC) and I found out today that its tires barely fit into the bike stand. I had to apply brute force to get them in and out. In addition, it wobbled around and I had to use a tension belt to keep everything in place and from falling over.    Questions:   Could this have any negative effects on the tires? (I am taking the bike every single day to commute and I leave it for 9+ hours. I would like to use the MTB at least half the time.) Is there any more elegant solution to this problem rather than using brute force / tension belts apart from adding a kickstand and than putting the bike next to the rack?   I would like to avoid a kickstand for the reasons mentioned in other threads such as . Right now I am considering adding a kickstand and removing it after work if I decide to take a detour through rougher terrain.  P.S. Please note that I have seen plenty of mountain bikes lying on the ground after work in the past. (Due to wind or people bumping into them etc..) However I would like to avoid this if possible.

I park my bike at work in a rack like this:    At the moment I have 26 x 1.9" knobbly tyres and the wheel just squeaks into the rack. However I'd like to replace these with 26 x 2" Schwalbe Marathons for a smoother ride and better puncture resistance, and these almost certainly won't fit.  What's the best way of putting my bike in this rack if the tyres won't fit, preferably without annoying colleagues by taking up more than one space? So far I've thought of:   using the lock cable to 'tie' the wheel to the side of the rack - possible but a bit of a faff fitting the bike with a kick stand so it doesn't need the rack to hold it upright - not ideal getting the 26 x 1.75" tyres instead - would work but I'd prefer the wider ones for best grip as my ride is partly on offroad paths and a cobbled street (and nothing to do with thinking the wider ones look better, honest).   But are there any other techniques or products I haven't thought of?  (Security of this type of rack is not a big concern, incidentally, as the rack is inside a shed with a code lock.)


This is one topic that I thought that I have already known well, but sometimes when I am writing a text or something like this it always come up the doubt of what should I use in the sentence to indicate possession. One example (stack in those sentences mean the abstract data type used in computer programming languages):   "The stack's top will have the value "0x3000." "The top of the stack will have the value "0x3000."   Well, for me both are right. However, I don't know what is the best choice. What's the most "polished" way to say that? Is there a real difference between those two options?  I've already searched the web but I couldn't find any trustful information that I can accept as a good answer to my problem. I saw that when you are relating a parto to a whole you should not use "'s", is this really true?  Is there any good way to remember the cases (or the logic) to use one of those forms?  In the cases that you can use both forms, what is the difference? Is there a informal and a formal way to say, or there is no difference at all?  Please correct any mistakes that I may have made in this text.

I gave a quick answer to part of  which had not been covered by previous answers, trying to clarify the reason you would say time of decoding but not decoding’s time. I said it was ’s usually indicates possession, but of course there were several counterexamples that would have occurred to me after a moment’s consideration, and these where helpfully supplied:   Britain’s climate two days’ time  a day’s work  the sun’s rays   I am still of a mind to say that possession of some sort is what allows the ’s. Even though the sun does not have title to its rays, they do belong to the sun. Now, at the risk of duplicating the original question and/or being pigheaded, I am curious as to why time of decoding but not decoding’s time is correct, if not for the reason I gave.


This is what the object looks like:   0: {Key: "1", Value: "cat1"} 1: {Key: "2", Value: "cat2"} 2: {Key: "3", Value: "cat3"} 3: {Key: "4", Value: "cat4"} 4: {Key: "5", Value: "cat5"}   HTML:  <select id="edit-category-dropdown" class="selectpicker" multiple data-selected-text-format="count > 3" data-style="custom-select">   I need to add dropdown options to this select element with value attrib = object.key and the innertext to = object.Value.    I want it in this format ideally.  <option value=object.Key>object.Value</option>  I have tried append to the element but it doesn't seem to work.  Update: apprently the issue was not my code that appended a new dropddown list but it was the fact that i didnt do a .selectpicker("refresh") on my select element. It fixed the issue with display.

What is the best method for adding options to a <select> from a JavaScript object using jQuery?  I'm looking for something that I don't need a plugin to do, but I would also be interested in the plugins that are out there.  This is what I did:  selectValues = { "1": "test 1", "2": "test 2" };  for (key in selectValues) {   if (typeof (selectValues[key] == 'string') {     $('#mySelect').append('<option value="' + key + '">' + selectValues[key] + '</option>');   } }   A clean/simple solution:  This is a cleaned up and simplified :  $.each(selectValues, function(key, value) {      $('#mySelect')           .append($('<option>', { value : key })           .text(value)); });   Changes from matdumsa's: (1) removed the close tag for the option inside append() and (2) moved the properties/attributes into an map as the second parameter of append().


A common result is that finitely generated modules over a PID $R$ are projective iff they are free.  Is the same true that an arbitrary projective module over a PID is free? I can't find this fact anywhere, so I suspect it is false, but I can't construct an example.  Does anyone have an example of a projective module over a PID which is not free? Thank you.

I have heard that any submodule of a free module over a p.i.d. is free.  I can prove this for finitely generated modules over a p.i.d.  But the proof involves induction on the number of generators, so it does not apply to modules that are not finitely generated.  Does the result still hold?  What's the argument?


Some people have taken interest in my pictures. Now personally, I don't believe my pictures are good enough to be printed.   However, if I were to print my pictures where do you even start with an asking point?   I can get them printed through flickr for like $100 or figure out the conversion method myself and have it printed through another company. I know metallic gloss always looks good (off topic).   How does someone know when they should start printing their photos and how much to ask for them?

I have recently shared an album of my pictures in an online photography forum and someone contacted me, asking if I can sell them a print, or the digital file for them to print themselves.   I have never sold any prints before and at the moment, I don't have time to spend on that; also I don't have any calibration tools for my monitor or any experience in high quality printing, and I don't want to half-ass that, so I don't want to sell a print right now. However, I'd be fine with selling the digital file so that person can print the photo. But I have no idea how to price a digital file, and what exactly I should give out.  Do you normally just send out a high-quality JPG? Or the RAW file along with the XMP file containing my edits? (I edited the picture in Lightroom) If I should go with JPG, do I just send out the full size (6000x4000) or ask them what size they want to print it in and send an appropriatly downsized version? And how do I determine an approriate price for that? What are the relevant factors?  I've read online that I should factor in the image size as well as the editing time. I don't know how long I spent on it, probably less than 10 minutes. I'm just not sure how to approach this, any price I could come up with somehow feels ... random. Some insights are appreciated!


It's not the first time that, in posting a question on Stack Overflow, I just can't find the tag I'm looking for.  I know I need 1,500 reputation points in order to create new tags, but is there some kind of way to overcome this rule (such as the review section if you don't have privileges to edit posts)?

Can someone please create the tag  on our site? We need to have it because        Foo is a recent/upcoming release / edition / model / episode of a popular, established OS / board game / bike brand / TV show   Foo is a hot new language / ingredient / game   we're currently using some other tag for questions about Foo, but it's causing ambiguity with a separate thing that's also named Foo      This is not a joke post. We get a lot of feature requests that ask for this or that tag to be created, and every time, a discussion ensues wherein people explain that there is no "tag creation department" and that community members create tags just by using them. I'm posting this "question" so that future requests of that type can be closed as a duplicate of this, saving time and eliminating redundant conversations for everyone involved.     See also:


When i passed an array as an argument to the function, the original array gets changed, but the array should not get changed right? please correct me if am wrong.  below i passed an int x=10 as an argument to change(int a) function. the value of the original int x got changed.  So how does the same code affects an array and int in different way?  public  class Runy  {  public static void main(String [] args)  {     Runy p = new Runy();     p.start(); }  void start()  {     long [] a1 = {3,4,5};     long [] a2 = fix(a1);      int x=10;     int y= change(x);      System.out.println(y);     System.out.println(x);      System.out.print(a1[0] + a1[1] + a1[2] + " ");     System.out.println(a2[0] + a2[1] + a2[2]);  }  long [] fix(long [] a3)  {     a3[1] = 7;     return a3; } int change(int a) {     a=a+1;     return a; }   }

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


Please let me know the size of UV filter that best suits Nikon 18-140 mm lens.

I was looking to get a circular polarizing filter and an UV filter for my Canon 550D, 18-135mm lens. When I checked online I found these filters came in different sizes, like 62mm, 67mm, 72mm, 77mm. How do I know which is right?  Also, will there be any degradation of photo quality if I put both these filters on the lens?


In the Harry Potter series, wouldn't the Elder Wand belong to Neville, not Harry? Since it belonged to Dumbledore, then Snape killed him, then Nagini killed Snape, then Neville killed Nagini, wouldn't it belong to him instead?

Harry takes Draco Malfoy's hawthorn wand, not the Elder Wand. How, then, does he become the master of the Elder Wand, which he never took from its true owner (Draco), or touched? Does a wizard lose the allegiance of all his wands if even one of them is taken from him? Pretty risky innit?