Question to original link:   I'm using Blender 2.78c, any ideas on making too. Nodes look different. I am trying make my signs Retroreflective for Farming Simulator 17.

How can I make a cycles material that gets very bright when a light is shown on it, yet still has normal colors? I'm talking about the "" that can be seen on road signs, the tape on big trucks (like in the image below), traffic barricades and clothing.  Image by TollGroup on    This reflective stuff has a interesting property where the colors show up perfectly well, but when exposed to a light source they seem to reflect much more light the normal.  has lots of good reference images.  I have tried different combinations of glossy and diffuse shaders, but none work as I have yet to get the super bright reflections.  How can cycles make a material that reflects so much light, and keeps the colors correct?


I'd like to encrypt my SD card for Android conveniently, safely and in a cross-platform way so that it can also be used on other devices. I asked about that .  As of right now there doesn't seem to be a way to do that (an app on FDroid or Playstore which doesn't put data at risk and is secure and very convenient/easy/fast to use).  This is why I decided to keep using the Android's default way of encrypting the SD card. However, this way it's not possible to access the data from other devices.  it has been described how data of the SD card can be decrypted from other devices but that way requires rooting the Android phone. Is it possible to do this without rooting the phone? In specific how could one get the .key file in /data/misc/vold?

I want to make sure that using adb backup -apk -shared -all -f ~/backup.ab will also save /data/misc/vold?   I am trying to backup before rooting, in order to be able to gain access to the encryption key in /data/misc/vold (got corrupted SD card adopted as internal). So I want to make sure ih something bad happens during the rooting, I could still access the backup version of /data/misc/vold?  Thanks!


I stumbled on the following inequality: For all $n\geq 1,$ $$2\sqrt{n+1}-2\sqrt{n}<\frac{1}{\sqrt{n}}<2\sqrt{n}-2\sqrt{n-1}.$$ However I cannot find the proof of this anywhere. Any ideas how to proceed?  Edit: I posted a follow-up question about generalizations of this inequality here:

Prove that $2(\sqrt{n+1}-\sqrt{n}) < \frac{1}{\sqrt{n}} < 2(\sqrt{n} - \sqrt{n-1})$ if $n \ge 1$ using induction.  Can someone help me with this problem please. Base case is easily shown, and for the inductive step I know I have to use the inequality for $n\gt1$ to show that it is true for $n+1$, but I am not quite sure how to.   Thanks.


I have downloaded latest version of Ubuntu 16.04 and am unable to initialize root login administrative access permissions inside of Terminal ?

I installed  (Precise Pangolin), 64 bit. Nowhere was I asked to set password for root.  I just installed  software. It was installed under the /root folder by default. Now I try do something on that folder. I tried with su to switch to root, but I don't know its password.   Should I always use sudo or get the default root password, if any?  How do I create a  for software installed inside the /root directory?


In X-Men DoFP we see that Trask Industries had developed a program to wipe out all mutants (the Sentinels). In the original timeline, though, where Mystique kills Trask and the American Government approves the "Sentinel" Program, why do we never get a single mention of it in X-Men 1, 2 or 3? Is it secret and it is uncovered only a few years after X3?  Note: This question is obviously different than  where the person who posted it is trying to figure out in which timeline every single event of the entire X-Men film series is happening, while my question is trying to explain if the absence of a mention to the "Sentinel" Program in the original X-Men trilogy is either a continuity error or is it explained somehow.

Through the X-Men film universe (X-Men 1-3, X-Men: First Class, X-Men: Days of Future Past, X-Men Origins: Wolverine, and The Wolverine), we see at least three distinct timelines/alternate realities.  The "Original" Timeline  Through X-Men 1-3 mutants are a largely unknown factor. X-Men 1 opens up in "the near future" (relative to the year 2000, when the film was released) with the public largely unfamiliar with mutants or their abilities. The "Mutant Registration Act" aims to identify and register mutants. The following films deal with mutants still being very much hidden, but there is no indication that they are being hunted or even identified in any large scale way until X-Men: The Last Stand when mutants voluntarily come forth. In these movies, the only mention of anything even remotely close to a Sentinel is a robot head in the Danger Room in X-Men: The Last Stand. In this timeline, when mutants appear, police are called, not Sentinels, and       Jean Grey and Cyclops both die (Jean dies twice).   The Days Of Future Past Timeline  In this timeline, Sentinels are used to hunt mutants and anyone with mutant genes.  The whole premise of the movie/Wolverine's mission is that       the assassination of Bolivar Trask in Paris in 1973 sets off anti-mutant hysteria, leading the US government to activate Trask's Sentinel project. In addition to the Sentinels, Trask has a device which can detect mutants (he has it with him at the Paris meeting which he is to be assassinated in). When the assassination fails, Trask already has a number of Sentinels built and ready to deploy, proving that while the updated Sentinels with adaptation ability are still a ways off, the technology for the Gen-1 Sentinels is largely ready - in 1973.   These two timelines are definitively different as      there are no Sentinels hunting mutants, nor is there any massive anti-mutant hysteria in X-Men 1 (at least, not to the level described in Days of Future Past)   The Altered Days of Future Past Timeline  Prior to Wolverine embarking on his mission, Kitty explains that should he succeed,       he will wake up back in their present (2023, I believe), but with history changed around him. Only he would remember the original Days of Future Past timeline with mutants having been hunted to near extinction.   In the end, we see this timeline      with Jean and Cyclops still alive and well in the 2023 present time.     Phew... Got all that?  The present story of The Wolverine opens with Wolverine having nightmares of when      he was forced to kill Jean Grey.   By itself, this doesn't mean that The Wolverine takes place in the "original" timeline, but we see a world where, as with the "original" timeline, there is no indication of mutants being hunted. Nor are there any mentions of Sentinels.  Conclusion: It is reasonable to assume that The Wolverine takes place in the same timeline/continuity as X-Men 1-3.  Right until we get to the post-credit scene  The Wolverine ends with      Logan flying off with Yukio, but only has bone claws.   The post-credit scene takes place later (2 years, IIRC). In this,      Wolverine sets off metal detectors, and is then approached by Professor Xavier and Magneto, hoping to recruit him for an upcoming battle. In the background, we see a commercial for Trask Industries playing on a TV.   The insinuation, of course, is that this scene is meant as a direct lead-in to X-Men: Days of Future Past, and that      Xavier and Magneto are recruiting him to fight the forthcoming Sentinels.   If we assume that The Wolverine and the post-credit scene are in the "original" timeline, then the post-credit scene is not a true lead-in.  If we assume that the post-credit scene is in the Days of Future Past timeline, then we are left to explain why no mutants have are being hunted by Sentinels already.  So... Which timeline does this post-credit scene take place in, or why is the history described in DOFP not reflected in X-Men 1-3?


I was reading my C++ book (Deitel) when I came across a function to calculate the volume of a cube. The code is the following:  double cube (const double side){     return side * side * side; }   The explanation for using the "const" qualifier was this one: "The const qualified should be used to enforce the principle of least privilege, telling the compiler that the function does not modify variable side".  My question: isn't the use of "const" redundant/unnecessary here since the variable is being passed by value, so the function can't modify it anyway?

How far do you go with const?  Do you just make functions const when necessary or do you go the whole hog and use it everywhere?  For example, imagine a simple mutator that takes a single boolean parameter:  void SetValue(const bool b) { my_val_ = b; }   Is that const actually useful?  Personally I opt to use it extensively, including parameters, but in this case I wonder if it's worthwhile?  I was also surprised to learn that you can omit const from parameters in a function declaration but can include it in the function definition, e.g.:  .h file  void func(int n, long l);   .cpp file  void func(const int n, const long l)   Is there a reason for this? It seems a little unusual to me.


For instance you're driving and there's a car ahead of you, it is very slow and hesitant. You find it irritating, what do you call the driver? Is there an expression to describe him or her?

I have heard terms like bikers, racers and car racers used for the people who drive quickly. But what are people called who drive slowly, or at normal speed, or very slowly (for old people who drive really slowly)?  Drivers cannot be use specifically for them as it denotes everybody.  So is there any particular term for these people?


I'm using the default LaTeX beamer theme. Unfortunately, for some reason, I don't get transparency anymore. The behaviour is the same across pdflatex, xelatex and lualatex.  Rendered:    MWE (requires an arbitrary image file):  \documentclass[compress,xcolor={usenames,dvipsnames,table},12pt]{beamer}  \title{Title} \author{Author} \date{September 14th, 2018}  \setbeamertemplate{background}{%   \includegraphics[width=\paperwidth,height=\paperheight]{background.jpg} }   \begin{document}    \begin{frame}     \titlepage   \end{frame}  \end{document}

Consider the following file:  \documentclass{beamer}  \setbeamercolor{title}{bg=red} \setbeamercolor{author}{bg=yellow} \setbeamercolor{date}{bg=} \setbeamercolor{institute}{fg=red,bg=green}  \title{TitelTitelTitel} \author{meiermueller} \institute{Institute} \date{lalala}  \begin{document}  \usebackgroundtemplate{\color{blue}\rule{20cm}{15cm}}    \begin{frame}    \titlepage  \end{frame} \end{document}   On one of my computers (using MiKTeX 2.9 and beamer 2015/01/05 3.36), the result is the following:    Note how, in particular, the date box has a transparent background  On my other computer, I installed a new MiKTeX version (2.9.6800), including beamer 2018/09/02 v3.52, and get this:    Here, the date field has a white background, and I cannot seem to get it to be transparent.   Apparently, the difference has some relation to the beamer version, or maybe some other change in the new MiKTeX version.  But what ist the reason, and how do I get transparent backgrounds?


In The Rise of Skywalker,       Kylo Ren takes an Imperial TIE Fighter from the Death Star II ruins to Exegol. Presumably he found the TIE Fighter in the Death Star ruins, since that's where he was left.   These ships have only ever been depicted as short-range fighter craft, and it seems to be from the Original Trilogy era, given where it apparently came from. How could it get between systems with no hyperdrive?

Near the end in amongst the battle, Kylo Ren lands next to his ship that Rey stole. I understand that at a stretch (or through the will of the Force) Kylo found a TIE Fighter in the wreck he was in, but to my understanding those TIEs would not have had hyperdrives, so how did he travel that far without a carrier ship? I suppose I'm guessing/assuming that he travelled on his own (Solo if you will), and not with his Star Destroyer, as the Knights who travelled with him on his Star Destroyer were already at the destination. But if the Force willed him to find the TIE Fighter, why not a shuttle with a hyperdrive? It would be iconic enough to use in the film, surely.  How did Kylo Ren travel to another system in a civil war era TIE Fighter with no hyperdrive or carrier ship?


I installed my OS but did not create a swap space. I now realize it is a problem. I have a 4GB ram and I will running huge applications. The below is the snip of my gparted. I opened Gparted but could not find swap on. I saw the accepted answer to  question. Will it work for me. In laymen terms, If I use those two commands can I forget about swap space and related things. Even more laymen, If I shutdown my system and restart it, will i then have to worry about swap space.

I did not create a swap partition during Ubuntu installation.  Later, I freed up some space and made a swap partition.  Now after each boot up, I am manually opening gparted to right-click the swap partition to turn on the 'swapon' option.  How can I automatically enable the swap partition at boot?  Also, if I had not created the swap partition, what are my other options?


Can we set up Passwordless SSH in Ubuntu (18.04) without root privileges? Is there any way to access files in /etc directory without root permissions? (I need to be able to set up Passwordless SSH between non-root users from between a local and remote system, but I don't have the root privileges on either system)

I want to be able to login to a remote via ssh without having to enter the password all the time.   How do I set it up? Is a different command required to execute a password-less session?


Ordinarily typing cmd > file will overwrite the file if it already exists. I often type >> to append, but get very worried about accidentally typing > and destroying my file. Is there an alternative command which doesn't risk me destroying a file if I mistype? Or alternatively, a way to make > ask for permission before overwriting existing files?

For an interactive session via SSH on a Linux cluster in Rstudio, it is very easy to accidentally execute the keyboard shortcut for "run in terminal" when commands are highlighted in Rstudio console. This results in behavior such as  \> library   or  Var1>Var2   being executed in terminal, which creates a library or Var2 file in the remote working directory if the terminal is logged in at the bash prompt.   In a worst case scenario this would result in overwriting files in the remote working directory.   I would like to disable ">" in these sessions, but I am not sure how to do this.


What is this 11.59 GB partition ?  Is that supposed to be there ? If not, what can it be and how can I remove it ?  I don't remember seeing it before I used Bootcamp and installed Windows. I installed Windows, it started crashing, and in the process of trying to fix and do a clean install of Windows, it seems that I crashed my Mac, too. And I am wondering if it's some sort of residue from a failed partitioning with Bootcamp.

In my Disk Utility, I see Other Volumes. It happened without me knowing and I have no idea how to check what that is.  Could you tell me what that is and if I can remove it using Terminal? Or without having to install other programs?


(CSIR-UGC NET, Mathematical Sciences, June 2017)     Consider the Vector space $V$ of real polynomial of degree  less than   or equall to $n$. Fix distinct real numbers $a_0, a_1,..., a_k$. For   $p \in V$   $$\max\{|p(a_j)|:0\le j\le k \}$$ define norm on $V$      (1)only if $k<n$.      (2)only if $k\ge n.$      (3)if $k+1\le n$.      (4) if $k+1\ge n.$   (Axiom 1(Positivity))$$\|p\|=\max\{|p(a_j)|:0\le j\le k \}\ge |p(a_j)|_{0\le j\le k }\ge0.$$ $$\|p\|=\max\{|p(a_j)|:0\le j\le k \}=0 \iff|p(a_j)|_{0\le j\le k }=0. $$ If $k>n$, which contradict the fundamental theorem of algebra. So, $p=0$.  (Axiom 2(Scalar Multiplication)) Easy to verify.  (Axiom 3(triangle inequality)) Easy to verify.  I got option 4. Am I right? I have a doubt about the proof of Axiom 1. Please verify my solution. Can you help me?

This question was part of my linear algebra assignment and I was unable to solv eit. SO, I am asking you for help.  Consider the vector space V of real polynomials of degree less than or equal to n. Fix distinct real numbers $a_0 , …, a_k$ . For $p \in V$ define $max${${|p(a_j)| : 0\leq j \leq k}$} . It defines a  norm on V if:  A only if k<n B only if $k\geq n$ C if $k+1 \leq n $ D if $k\geq n+1$ I tried thinking on which result / reasoning I should use but I am clueless on when the norm will not be defined . Can you please help me through it?


I made a function find_all which returns a vector of position(iterator) of all position of element xr in a STL container ar. What`s wrong with this code.  template<typename T1, typename T2 = T1::value_type> auto find_all(const T1& ar, T2 xr) {     typedef T1::const_iterator const_iterator;     vector<const_iterator> it;     for (auto it2 = ar.cbegin(); it2 != ar.cend(); ++it2)         if (*it2 == xr)             it.push_back(it2);     return it; }   The code compiles in Visual C++ 2015, but gives following error with gcc compiler: Error :   prog.cpp:3:38: error: need 'typename' before 'T1::value_type' because 'T1' is a dependent scope   template<typename T1, typename T2 = T1::value_type>                                       ^ prog.cpp: In function 'auto find_all(const T1&, T2)': prog.cpp:6:11: error: need 'typename' before 'T1::const_iterator' because 'T1' is a dependent scope    typedef T1::const_iterator const_iterator;            ^ prog.cpp:7:10: error: 'const_iterator' was not declared in this scope    vector<const_iterator> it;           ^ prog.cpp:7:24: error: template argument 1 is invalid    vector<const_iterator> it;                         ^ prog.cpp:7:24: error: template argument 2 is invalid prog.cpp:7:28: error: invalid type in declaration before ';' token    vector<const_iterator> it;                             ^ prog.cpp:10:8: error: request for member 'push_back' in 'it', which is of non-class type 'int'      it.push_back(it2);         ^     I want to simply correct it.

In templates, where and why do I have to put typename and template on dependent names? What exactly are dependent names anyway?    I have the following code:  template <typename T, typename Tail> // Tail will be a UnionNode too. struct UnionNode : public Tail {     // ...     template<typename U> struct inUnion {         // Q: where to add typename/template here?         typedef Tail::inUnion<U> dummy;      };     template< > struct inUnion<T> {     }; }; template <typename T> // For the last node Tn. struct UnionNode<T, void> {     // ...     template<typename U> struct inUnion {         char fail[ -2 + (sizeof(U)%2) ]; // Cannot be instantiated for any U     };     template< > struct inUnion<T> {     }; };   The problem I have is in the typedef Tail::inUnion<U> dummy line. I'm fairly certain that inUnion is a dependent name, and VC++ is quite right in choking on it. I also know that I should be able to add template somewhere to tell the compiler that inUnion is a template-id. But where exactly? And should it then assume that inUnion is a class template, i.e. inUnion<U> names a type and not a function?


My code is :

My product title

My product small description and text
         Read more »
   Is my code correct and good for seo ?

I am trying to use
 tags on my blog for the post title and came across one problem. Title is hyperlinked.  Case 1:
  xyz
   case 2:
 xyz
     Which one is better in terms of SEO?


I like that Cmd+Shift+N creates a new folder in the current directory in Finder. I would like to have a similar command like Cmd+Control+N or Cmd+Control+Shift+N that creates an empty text file in the current directory.  There's quite a bit of discussion on  and on this site,  and .  However, some of the solutions seem out of date, others are mouse driven, or involve somewhat elaborate multi-click processes.  How can I assign a shortcut key like Cmd+Control+N to create a new empty text file in Finder on OSX?

In Windows, one can create a new file using Right Click -> Add New -> Type of File. Is there an analogous action in Lion?  I just want to create a new blank file on my Desktop.


After having found the image below, I’m wondering whether there is a word that English speakers use to describe someone driving on the opposite side of a road.  A bit of searching pulled up , which is a German word whose translation into English is at best unclear. In fact, according to Google Translate, geisterfahrer is rendered in English as ghost rider. However, I’m unable to find this two-word phrase in any dictionary I have consulted — and besides, I’m interested to find a single word.   Thus my question is, is there a word for someone who drives in the direction opposite the one prescribed for the lane they are driving in?  Note that I dislike, and will not accept, wrong-way rider, both because it is too far from the single-word concept and because it seems like a made-up phrase to me.

According to  (warning: sarcasm), there is no English equivalent for "Geisterfahrer", or someone who drives into oncoming traffic. I know there is a Dutch word ("spookrijder"), but apparently there is no succint term for such a driver in English. What would be the best term to describe that? I assume radio has a term for it in their traffic bulletins, but I don't know what they call it.  Example sentence:     A {Geisterfahrer equivalent} has been spotted on the M4 near Windsor heading towards London. Please keep to the far left and do not overtake other drivers.


Does the Merkle–Damgård hash function still offer Collision Resistance (CR) when the following changes are made? Each case is independent from the other.  Here is what I want to modify:   Say I want to get rid of the IV at the beginning and replace it with the first block of the message ($M_1$). That is, $T_0 = M_1$ and the 2nd tag $T_1$ will be generated using the compression function $h$, so that $T_1 = h(M_1,M_1)$. Instead of what it should have been: $T_1 = h(IV,M_1)$. Instead of using IV as the first tag $T_0$ and adding the message length in the last block, set $T_0$ to be the the message length $q$ (such that it is padded to the block length). Instead of outputting the result of Merkle–Damgård $H(m) = h(T[i-1]; M[i])$ we just output $T[i-1] || M[i]$, where $||$ denotes concatenation. Assuming in this version of Merkle–Damgård, the last block will just be the length of the message.   Can someone tell me if any of this cases offers Collision Resistance? Please explain why this is the case.

In Merkle–Damgård is there any reason why we use a fixed $IV$ at the beginning? Can we use the first block ($M_1$) right away instead of $IV$ and feed it through the compression function with $M_2$.


In StackExchange sites that support MathJax the inline markup is rendered in comments but not chat rooms -- at least I noticed this is the case on .  This is awkward, particularly for comment discussions that are moved to chat.

It would be really nice to be able to use MathJaX (math formulas) in chat.  Not specially for formulae, but for things like $V_{CC}$ in electronics chat would be very useful.


When I run the  app it shows nothing (see below) instead of picture from my webcam.    However guvcview (a webcam viewer app) recognizes my webcam and I see the picture from it.

Cheese Booth shows an error:     There was an error playing video from the webcam     I test if webcam works fine or not by opening google hangout, its works fine.    Please tell, what is the issue in cheese booth.  Note: Sometimes the cheese booth works fine but most of time not


Prove that there are infinitely many integers $x$, $y$ and $z$ satisfying the equality   $x^x\times y^y = z^z$   i'm sorry but i have no idea about how to start.

Question : Do there exist an infinite number of integer-solutions $(x,y,z)$ of $x^x\cdot y^y=z^z$ where $1\lt x\le y$ ?  Motivation : After struggling to find a solution, I've just got one solution, which is  $$(x,y,z)=(1679616, 2985984, 4478976).$$  In the following, I'm going to write how I got this solution.  Letting $d$ be the greatest common divisor of $x,y,z$, we can represent $$x=ad, y=bd, z=cd$$ where $a,b,c$ are coprimes with each other. Then, we get $$d^{a+b-c}\cdot a^a\cdot b^b=c^c.$$  In the following, let's consider without the condition $x\le y$. Here, I suppose  $$a=2^m, b=3^n, a+b-c=1.$$  (As a result, this supposition works.)  Then, we get $$d=\frac{c^c}{2^{ma}\cdot 3^{nb}}.$$  Hence, letting $c=2^k\cdot 3^l$, if  $$kc\ge ma=m\cdot 2^m, lc\ge nb=n\cdot 3^n,$$ then $d$ is an integer.  Since $(m,n)=(4,2)$ satisfies the above conditions, then we get $d=2^8\cdot 3^6=186624.$ Hence we can get  $$x=9d=2^8\cdot 3^8=1679616, y=16d=2^{12}\cdot 3^6=2985984, z=24d=2^{11}\cdot 3^7=4478976.$$ Note that here I interchanged $x$ and $y$.  P.S : I was surprised to get this solution because I got this almost by chance. So, I don't know the other solutions. If you have any helpful information, please teach me.


It has been claimed that at U.C.L.A. at least 40% of the students live on campus. From a  sample of 250 students, 90 live on campus. Does the evidence support this claim at a  = 0.01 .  What i did is   Ho: P is greater or equal to 0.4  Ha: P is less than 0.4  The critical value comes out to be -2.33 from the table  Now how to calculate the test statistics? Also is my critical value correct?


The formula for Work is F*x, where x is distance taken. So by physicially work formula, why don't we experience any work if we do not make any object move? Is there a specific reason?  Example, I am pushing a table with 10 N and distance travelled is $1m$, thus $W = 10 N*m$. But when table travels $0$ metres, by the formula $W = F*0$ and thus $W=0$; means that we didn't do any work.  So why is that? At the end of the day we did apply force to table?

I read the definition of  as  $$W ~=~ \vec{F} \cdot \vec{d}$$  $$\text{ Work  =  (Force) $\cdot$ (Distance)}.$$ If a book is there on the table, no work is done as no distance is covered. If I hold up a book in my hand and my arm is stretched, if no work is being done, where is my energy going?


I know this has happened a lot in the past but I was just snookered into clicking a link for duapp.com after searching google.  stackoverflow.duapp.com/questions/23268645/how-to-read-xml-with-ruby  Like 'real' SO search results, "stackoverflow" comes first in the line so it was easy to make that mistake (I expect intentionally so).  To add to confusion duapp.com after a series of redirects you're directed to page where you can share a 404 error page on social media. duapp.com is hosted by Baidu, but I won't get on my soapbox about that.  Is there anything we can do to remove these useless results from Google search? Is there somewhere else I should report this?

of Stack Overflow, all content posted on Stack Exchange sites by their users (i.e. you wonderful people) has been provided to the whole universe under . For my fellow non-lawyers, that license basically means:   Anyone can use any Stack Exchange posts at any time without having to ask for permission Making money off of the copied content is permitted You don't even have to copy stuff from here verbatim; you can just use it as a starting point and make whatever edits you want There are just two rules you have to follow:   You have to provide . Simple links to the original post and author info are just fine. You have to  and allow other people to use your content, as long as they follow these very same rules. How meta!    (If you ever forget any of that, and want to refresh your memory, the license info is linked to in the footer of every page.)  There are, in fact, a lot of people who republish varying amounts of our content for assorted reasons. Unfortunately, there are some Stack Content Republishers Attributing Poorly and/or Excelling at Ranking (SCRAPERs, for short).  In this context, "attributing poorly" means any use that doesn't follow our attribution rules or make any other reasonable attempt at give credit. This can get pretty egregious; I've seen SCRAPERs that not only don't link back to SE originals, but also use fake author info and post dates to make it harder to find originals. By "excelling at ranking," I'm referring to copycat sites that end up higher in Google results than the original SE sites do for the same content. That's not necessarily wrong, but in some cases, it indicates inappropriate SEO hackery.  So, the question is: what can you do if you spot a SCRAPER?


I've earned a Tumbleweed badge — but that doesn't seem like a good thing.  Is it?  I initially thought "earning" a badge was positive, but it seems to me that the implication is that I asked a question that was too obscure.  So: is it a good or a bad thing?  Do I want to collect more?!  =:-)

What is the purpose of the tumbleweed badge? Why is asking questions no one answers or looks at a desirable accomplishment?


Prove that for every prime $p>3$,   $L= x^2-x+2 \equiv 0\mod p$ has a solution iff $D=x^2-x+16 \equiv 0\mod p$ has a solution.  This is not true, right? If $L \equiv 0$ mod$p$, then $D=L+14 \equiv 14\mod p$, and $14$ is not congruent to $0\mod p$, when $p \neq 7$.

Let $p$ be a prime number. Prove that there exists $x∈Z$ for which $p|x^2−x+ 3$ if and only if there exists $y∈Z$ for which $p|y^2−y+ 25$.   I've copied the question verbatim from an elementary number theory assignment.  I'm not making much ground on it, but here's what I've determined so far:  Each equation is based on the following sequence:  x^2 - x: 0, 2, 6, 12, 20, 30, 42, 56, 72, ...   I'm not sure what to call this type of sequence, but I'm thinking of it as a sequence with an acceleration of $2$, as in, each number on the sequence is increased by a number which is increased by $2$ each iteration.  The only difference between the two equations is the starting point of the sequence: one starts at $3$ while the other starts at $25$.  This is how I have been thinking about the problem but unfortunately I think I'm working in the wrong direction.  If anyone could help me move in the right direction of this problem, I would appreciate it


Does anyone know a way of defining particle colours by where they emit form on an object and have them stay that colour instead of just mirroring the emission object? I've got particles emitting from an object with a colourful Voronoi pattern on it to another object with a force field and turbulence so the particles mix and move around once stuck to it. At the moment I have the colour pattern mapped on to the particles using a texture coordinate, mapping and color ramp but the pattern is just projected onto the particles. What I want is for the particles to have their colour defined by where they emit from and then keep that colour so that they mix in the turbulence. Is there a way of doing that? Many thanks in advance.

I am using Blender's particle system to try to voxelize my mesh. I'd like to color the voxels based on the diffuse color of the textured mesh at the closest location to each voxel. This is an image that shows what I'm trying to do:     explains how to color emitted particles based on the mesh from which they are emitted. The technique uses the "jittered" emission setting:    Using the technique in the post I linked to, here is what I get with "jittered" selected. You can see that the emitted cubes correctly match the color of the mesh:    When I change the emission setting to "grid", the cubes no longer match the color of the object:    I'd like to use the "grid" emission setting for voxelization, but can't figure out how to get the color of the emitted particles to correctly match the color of the mesh.   This is what my shader nodes look like for the cube which I am using as the dupli object:    I'd appreciate any help with this! Please let me know if there's something I can clarify.


I want to write a function that takes an optional argument and changes its behavior depending on whether or not that argument is provided. This is the first way I thought to do this:  function foo(optionalArg) {     if (optionalArg) {         // do something with the optionalArg     } else {         // do something different     } }   Is this the best way to do this, or is there a safer/better way?  EDIT: If you actually read the question, you'll notice that it's different than the "duplicates" some claim this is. I know how to provide default values to a function's arguments; I found those links when I was trying to figure this out on my own first. But I'm not looking for how to do that. I'm looking for the best way to change my function's behavior based on whether or not the argument was provided.

I've always handled optional parameters in JavaScript like this:  function myFunc(requiredArg, optionalArg){   optionalArg = optionalArg || 'defaultValue';    // Do stuff }   Is there a better way to do it?  Are there any cases where using || like that is going to fail?


i need to boot ubuntu from my usb drive.i did not face problems when creating with pendrive linux but nothing is displayed on the boot screen?

I tried to use the usb-creator.exe from Ubuntu 10.10 desktop i386 ISO image and it does create an USB stick that doesn't boot. When I try to boot from it I get:     Operating System not found.   I try to do this from Windows 7 x64. I'm not looking to create a live Ubuntu media, only an installation USB disk.  I repeated the process several times and I even tried to reformat the USB drive (FAT32), no success yet.  The USB stick is a 8GB one.


Theorem Every orthogonal matrix in $\mathbb{R}^{2, 2}$ is in the form   \begin{bmatrix} \cos\theta & -\sin\theta \\ \sin\theta & \cos\theta \end{bmatrix}   or   \begin{bmatrix} \cos\theta & \sin\theta \\ \sin\theta & -\cos\theta \end{bmatrix}   I am able to prove that $$\mathbf{M} = \begin{bmatrix}      a & \pm b \\      b & \pm a     \end{bmatrix},     |\operatorname{det}(\mathbf{M})|     = |a^2 \pm b^2|     = 1,$$ but I don't know how to continue.

I'd like to prove that any orthogonal $2 \times 2$ matrix can be written   $$\bigg(\begin{matrix}    \cos x & -\sin x  \\     \sin x & \cos x   \end{matrix}\bigg) \hspace{1.0em} \text{or} \hspace{1.0em} \bigg(\begin{matrix}    \cos x & \sin x \\    \sin x & -\cos x \end{matrix}\bigg)$$  for $0 \le x < 2\pi$.  I have no idea how to do this. I feel like this is something I've missed and is really straightforward but I can't find it in my book...


I saw a post in Quora that stated the above. I'm wondering how come we get a negative I know that the sum is approaching infinity. Does that mean that infinity means approaching zero ? No right? Because infinity in my point of view, just means increasing without bounds. Anyways. am I correct? I always though of infinity more of a concept rather than a number. If anyone can explain why is this, I  would really appreciate it.

$\displaystyle\sum_{n=1}^\infty \frac{1}{n^s}$ only converges to $\zeta(s)$ if $\text{Re}(s) > 1$.  Why should analytically continuing to $\zeta(-1)$ give the right answer?


How to root a xperia mini device? is it safe? Am i need a program or an app? is there an open source or private application  for this procedure?

I searched it a while and found some articles regarding Xperia Mini X10 also on XDA but I couldn't understand them easily. So I want help from you geeks who can give me the lighted way with simple steps to root my phone.    I want a step by step guide about to root this model. I'm a not much familiar with this technology so please guide me through some detailed answer.


Say I want to migrate from Ubuntu to Debian, or the other way around, how can I reinstall all of my apps on my new system? For config it is super simple, just back up the home folder, but is there an easy way to reinstall all of your apps/software on the new system in an automated and simple manner?  Thanks

If I want to make a backup of everything I have done since the fresh install of Ubuntu, what are the possible options? What all should I backup? I want to get all the settings that I changed, all the packages I installed, etc.


Obviously this is possible (as Class has isPrimitive() method) but how I can do this directly? E.g. reflection api able to cast a primitive type to Class: import java.lang.reflect.Method;   public class TestClass {                 public static void m(){}         public static void m(Object o){}         public static void m(int i){}         public static void m(Integer i){}                 public static void main(String[] args){                                 TestClass tc=new TestClass();                 Method[] mtds=tc.getClass().getDeclaredMethods();                                 for (int i = 0; i < mtds.length; i++) {                         System.out.print(mtds[i].getName());                         Class[] prms=mtds[i].getParameterTypes();                         for (int j = 0; j < prms.length; j++) {                                 System.out.print("-"+prms[j].getCanonicalName());                                                                 }                         System.out.println();                 }                 } }  output is:  m m-java.lang.Object m-int m-java.lang.Integer main-java.lang.String[]  Integer and int are different so it is not autoboxing. Anything (except creating an utility class with reflection and getParameterTypes() ) do not come at my mind (everything else I've tried failed).

I need to make some reflective method calls in Java. Those calls will include methods that have arguments that are primitive types (int, double, etc.). The way to specify such types when looking up the method reflectively is int.class, double.class, etc.  The challenge is that I am accepting input from an outside source that will specify the types dynamically. Therefore, I need to come up with these Class references dynamically as well. Imagine a delimited file a list of method names with lists of parameter types:  doSomething int double doSomethingElse java.lang.String boolean   If the input was something like java.lang.String, I know I could use Class.forName("java.lang.String") to that Class instance back. Is there any way to use that method, or another, to get the primitive type Classes back?  Edit: Thanks to all the respondents. It seems clear that there is no built-in way to cleanly do what I want, so I will settle for reusing the ClassUtils class from the Spring framework. It seems to contain a replacement for Class.forName() that will work with my requirements.


Let AB and CD be two intersecting chords of a circle. How can I find the coordinates of the intersection point knowing only the euclidean coordinates of the endpoints A,B,C,D and the circle center point?  This can of course be solved with a segment-segment intersection algorithm (thanks for marking this question as duplicate, everyone), but I am asking if there is a simpler or more efficient algorithm that exploits the fact that the two line segments are chords of the same circle.

I need to find the intersection point of 2 line segments (lines are finite, i.e., they have end points).   e.g. segment 1 from $(x_1, y_1)$ to $(x_2, y_2)$ -- segment 2 from $(x_3, y_3)$ to $(x_4, y_4)$  you can assume $m_1$ and $m_2$ are the gradients of segment 1 and segment 2 respectively  similarly, $c_1$ and $c_2$ being the y-intercepts of segment 1 and segment 2 respectively  Using $y=mx+c$ I can easily find the equations of both lines and then derive the intersection point from those equations and check if that point actually lies on both the line segments (intersection point may not lie between the end points).  My problem is when I calculate the gradients $m_1$ and $m_2$ I do $\frac{y_2-y_1}{x_2-x_1}$ there for if one of the lines is vertical then I am going to have problems. How can I deal with this?  Another problem is that if the two segments intersect at a point which is also the same as one of the end points then I want to assume that they are not intersecting.  e.g. if segment 1 is from $(2, 3)$ to $(3, 7)$ and segment 2 is from $(3, 7)$ to $(7, 3)$ then I want to assume they don't intersect.


There are so many Stack Exchange websites and some of them are very similar (it's hard to tell them apart) that for some questions I don't know which one of them I should choose.  Consequently, I ask the same question multiple times, deleting and moving it to the next community with the hope to find the right one someday.  So my question is: is there a website where you can ask questions you don't know where to ask? Such a question could then be moved to the most appropriate website.  If not, could there be one? I don't want to make the same search trip every time and I think it's very unlikely that anybody would read all the FAQs first to be able to identify the right community.

Is there a catch-all place somewhere on the Stack Exchange sites where one can post a (any) question that does not obviously belong to any of the Stack Exchange sites?  Sometimes I have questions but I don't want to ask them on other sites (no need for names). I prefer to post it on the Stack Exchange network for various reasons.  If there isn't, are there plans for one? I imagine that if such a site exists, questions on that site can also be moved to other more specific sites when they exists, and it's not to be used to post questions which obviously belong to a specific Stack Exchange site.


I´m creating a new append html element but it lose the functionality to use on key up.  Is there anyway to fix that (I can use ES6 but including more frameworks on this project could be hard since it´s legacy code. I´m with JQuery and JQuery UI)  I tried to read a lot about it but is seems that when you create a HTML element with append the functionality is lost.              } else if (opcaoSelecionada === 'cidade'){                     var microtime = Date.now();                     $('#add_destino').prepend   (`

                         Type a country name                         <input type="text" name="country" id="country" placeholder="Enter country name" class="form-control">

                     `);                 }             }              $('#country').on('keyup',function() {                 console.log('Teste');                 var query = $(this).val();                 console.log(query)                 $.ajax({                     url:"http://localhost/autocomplete/cidadeTourCode",                     type:"GET",                     data:{'cidade':query},                     success:function (data) {                     $('#country_list').html(data);                     }                 })             });               $(document).on('click', 'li', function(){                 var value = $(this).text();                 $('#country').val(value);                 $('#country_list').html("");             }); ´´´

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


My Blender doesn't render textures in Cycles anymore. It worked before but if I now create a new project and apply a texture to an object it just gets rendered in a color present in the texture (see image).  I tried:  * restarting  * creating new prject  * using different texture format (png/jpeg)  * Changed render device (CPU/GPU)      I'm sure I didn't change any settings. I hope it's just something really simple I forgot :D  Thanks in avance for your help =)

Because I am pretty new to blender I watched the tutorial  from BlenderCookie.com.  I loaded  onto a sphere but then in all views the texture is just some kind of blurry with no details.


So we all know you  for many reasons, mostly due to filenames allowing almost every character.  However why has nobody been able to overcome this in an implementation of ls? Many commands have a command line argument that will output parsable text to stdout, often csv format. Now I know filenames can have commas but so can csv files, that is a simple fix using double quotes.  I guess another issue would be that filenames could also contain double quotes, but I still refuse that the open source hivemind couldn't find some solution to this.  What is preventing someone from implementing a parsable option for ls?

This question was prompted by questions about ls' -1 option and the recurring tendency of people to ask question and answers that includes processing the output of ls.   This reuse of the output ls seems understandable, e.g.: if you know how to sort a list of files with ls you might want to use the output in that way as input for something else.  If those Q&A don't include a reference to the file name list produced consisting of nicely behaving file names (no special characters like spaces and newlines), they are often commented upon by someone pointing out the danger of the command sequence not working when there are files with newlines, spaces etc.  find, sort and other utilities solve the problem of communicating "difficult" file names to e.g. xargs by using an option to separate the file names with the NUL character/byte which is not a valid character in file name (the only one in addition to /?) on Unix/Linux filesystems.  I looked to the man page for ls and the output for ls --help (which has more options listed) and could not find that ls (from coreutils) has an option to specify NUL separated output. It does have a -1 option which can be interpreted as "output file names separated by newline")  Q: Is there are technical or philosophical reason why ls does not have a --zero or -0 option that would "output file names separated by NUL"?  If you do something that only outputs the file names (and not use e.g. -l) that could make sense:  ls -rt -0 | xargs -r0 …   I could be missing something why this would not work, or is there an alternative for this example that I overlooked and that is not much more complicated and/or obscure.    Addendum:  Doing ls -lrt -0 probably does not make much sense, but in the same way that find . -ls -print0 does not, so that is not a reason to not provide a -0/-z/--zero option.


I have this 2 lines in my code:  String csvPath = "D:\\myFolder";  Scanner scanner = new Scanner(ReadCSV.class.getResourceAsStream(csvPath + "\\myFile.csv"));   It gets me a null pointer error. I think it is because it is trying to find it under project path. How can I make this work without omitting the scanner? Is it possible to make it work wit getResourceAsStream() ?

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 have created an Apex class with an SOQL query to get OpportunityLineItems. Testing the SOQL in query editor returns the expected response. All of the fields render in the LWC data table except for Product2.Name.   @AuraEnabled(Cacheable = true) public static List<OpportunityLineItem> getOpportunityLineItem(){     return [SELECT Id, Product2Id, Product2.Name, Quantity, UnitPrice, ProductCode FROM OpportunityLineItem]; }   Columns from LWC        const columns = [     {         label: 'Product Name',         fieldName: 'product2.Name',         type: 'text',         cellAttributes: { alignment: 'left' }       }, {         label: 'Quantity',         fieldName: 'Quantity',         type: 'number',         editable: true,         cellAttributes: { alignment: 'left' }      }, {         label: 'Sales Price',         fieldName: 'UnitPrice',         type: 'currency',         editable: true,         cellAttributes: { alignment: 'left' }     }, {         label: 'Product Code',         fieldName: 'ProductCode',         type: 'text',         cellAttributes: { alignment: 'left' }      }  ];

I have fetched all the fields to be displayed on the datatable in my apex query.  In my js file where i store the column details  @track columns = [{         label: 'Deal Name',         fieldName: 'Marketing_Activity__r.Name',         type: 'text'                 },     {         label: 'Deal Type',         fieldName: 'Deal_Type__c',         type: 'text'      },     {         label: 'Rent',         fieldName : 'Rent__c',         type: 'currency'      },     {         label: 'Term',         fieldName : 'Term_Mos__c',         type: 'number'     },     {         label: 'Security Deposit',         fieldName: 'Aircraft__r.Lease__r.Security_Deposit_Amount_Cash_or_LOC__c',         type: 'currency'      }   It fetches value for rent,term and deal_type. but not for Security deposit and Deal Name. Any suggestions??? How to display the above details on the datatable in lwc?


The problem: For all positive integers $a$ and $b$, if $(a, b)=1$, then $(a+b)^{\phi(a)\phi(b)}\equiv(a^{\phi(b)}+b^{\phi(a)}) \pmod{ab}$.  My work thus far. I know that by using Euler's theorem I can show that $(a^{\phi(b)}+b^{\phi(a)})\equiv1 \pmod{ab}$.  I am currently stuck trying to show that $(a+b)^{\phi(a)\phi(b)}\equiv1\pmod{ab}$, and then putting that with my idea above to complete the proof.  Can anyone give me any hints or let me know if I am on the right track? Thanks!

I would like to prove the following equality: $$k^{\phi(l)} + l^{\phi(k)} \equiv1\pmod{lk}$$if $\gcd(l,k)=1$. What methods can I use? Thank you for your help.


Today, I see such a wierd way of indexing the arry.  The code is like:  int array[] = {10, 20, 30}; cout << -2[array];   I've never seen such a strange way of using array. But there is no compilation error.  Can anyone tell me does the ISO document evolve the description for this way of using array?

As Joel points out in , in  (aka: K & R), there is mention of this property of arrays in C: a[5] == 5[a]  Joel says that it's because of pointer arithmetic but I still don't understand. Why does a[5] == 5[a]?


I have a big problem and I can't fix it So i was installing windows and removed the partition from there and got an error that i can't use this hard drive so i restarted my computer and got this error and now i don't know what to do, i just wanted to clean my disk and use it on windows  and i don't have access to bios or boot menu i don't know why  The command line here:  [  1.184301] nouveau 0000:01:00.0: bios: 00B 1 d7500086 d7500086  /dev/sda1: The filesystem size (according to the superblock) is 244190208 blocks  The physical size of the device is 244189952 blocks  Either the superblock or the partition table is likely to be corrupt!   /dev/sda1: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.          (i.e., without -a or -p options)  fsck exited with status code 4  The root filesystem on /dev/sda1 requires a manual fsck   BusyBox v1.22.1 (Ubuntu 1:1.22.0-19ubuntu2) built-in shell (ash)  Enter 'help' for a list of built-in commands.   (initramfs)

I dual boot Ubuntu and Windows 7. I was browsing on FireFox in Ubuntu and all of a sudden I get some error message, so I rebooted.  Now when I try to boot into Ubuntu I get this message:  fsck from util-linux 2.26.2 /dev/sda6 contains a file system with errors, check forced. /dev/sda6: Inodes that were part of a corrupted orphan linked list found.  /dev/sda6: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.         (i.e., without -a or -p options) fsck exited with status code 4 The root filesystem on /dev/sda6 requires a manual fsck  Busybox v1.22.1 (Ubuntu 1:1.22.0-15ubuntu1) built in shell (ash) Enter 'help' for a list of built-in commands.  (initramfs) _   How can I fix this?


Let $$G=\{z\in \Bbb{C}\mid z^n=1 \quad\text{for some }n \in \Bbb{Z}^{+}\}.$$ Show that for any fixed integer $k>1$, the map $z\mapsto z^k$ from $G$ to itself is a surjective homomorphism but not an isomorphism.  Proving that the map is a homomorphism is easy - for any $z_1,z_2 \in G$ we have $\varphi(z_1z_2)=(z_1z_2)^k=z_1^kz_2^k=\varphi(z_1)\varphi(z_2)$. Proving that it is not an isomorphism is also straightforward - since $\operatorname{ker}\varphi=\{z\in G \mid z^k=1\}$ which is not $\{1\}$, we can conclude that the mapping is not an isomorphism. I just need some hint to show that the mapping is surjective. Thanks in advance!

I'm having difficulty showing the given a map, say $\phi(z)=z^k$, is surjective. This question is from D & F section 1.6 - #19     Let $G$ =$\{z \in \mathbb C|z^n=1 \text{ for some } n \in \mathbb Z^+\}$. Prove that for any fixed integer $k>1$ the map from $G$ to itself defined by $z \to z^k$ is a surjective homomorphism, but is not an isomorphism.   To show $\phi(z)=z^k$ is a homomorphism let $z_a=e^\frac{2\pi ia}{n}$ and $z_b=e^\frac{2\pi ib}{n}$ where $a,b\in \mathbb Z^+$ and $a\neq b$ then $\phi(z_az_b)=(e^\frac{2\pi ia}{n}$$\cdot$$e^\frac{2\pi ib}{n}$)=$e^\frac{2\pi ik(a+b)}{n}$=$e^\frac{2\pi ika}{n}$$\cdot$$e^\frac{2\pi ikb}{n}$=$\phi(z_a)\phi(z_b)$.  I had what I thought was a proof for $\phi$ being surjective until I thought about this specific example. Here's the example: Suppose $z_a$ is a root of unity then so is a power $z^t_a$. My thoughts on $G$ are that it consists of all integer powers of the "basic" roots of unity for a partiuclar $n$. Let $n=3$ and $k=3$, then $\phi(e^\frac{2t\pi ik_i}{3})=(e^\frac{2t\pi ik_i}{3})^3 =e^{2t\pi ik_i}= 1$ for any integer $t\in \mathbb Z$ and integer $k_i$ such that $0\leq$$k_i$$\leq$ $2$. So we have $\phi[G]=\{1\}$, $\phi$ is not surjective in this instance.  What have I misunderstood about the question? Are there any glaring errors I'm making? Is $n$ supposed to be a particular value and not just any integer value?  Your help is appreciated.


Let $f(x)$ be a quadratic expression which is positive for all real values of $x$. If $g(x)=f(x)+f'(x)+f''(x)$, then for any real $x$,   $$(A)\, g(x)<0,\quad (B)\,g(x)>0,\quad (C)\, g(x)=0,\quad (D)\;g(x)\ge 0.$$   My work so far.  Let $f(x)=ax^2+bx+c$ be the quadratic polynomial. Then $b^2-4ac<0$ and $$g(x)=ax^2+x(b+2a)+(c+b+2a).$$ Now I am stuck. I am not able to pick the right answer.

If $f(x)$ is a quadratic expression such that $f(x)>0\;\forall x\in\mathbb{R},$ and if $g(x)=f(x)+f'(x)+f''(x),$  Then prove that $g(x)>0\; \forall \; x\in \mathbb{R}$.  $\bf{My\; Trial \; Solution::}$ If $f(x)>0\;\forall x\in \mathbb{R}$. Then function $f(x)$ has Minimum value .  Let Minimum occur at $x=x_{0}$. Then $f(x)_{Min} = f(x_{0})>0$  Now Given $g(x) = f(x)+f'(x)+f''(x)$. Then $g'(x) = f'(x)+f''(x)+f'''(x).$  Now at $x=x_{0}\;\;,$ Value of $g(x_{0}) = f'(x_{0})+f''(x_{0})+f'''(x_{0}) = 0+f''(x_{0})+f'''(x_{0})$  Now I did not understand How can i solve after that,   Help me   Thanks


Whenever I'm dealing with numbers in PHP which represent money, I'm forced to use bcadd() and the other functions in that "family", instead of simply using the nice symbols such as +, -, / and *. The reason is something about "floats" being inaccurate for some reason. I've many times tried to understand why exactly this is, but I can't make any sense of it. It would be much nicer to use the symbols instead of the BC Math functions. Why aren't the floats just accurate instead? Or made into "numerics" if "floats" by their nature are inaccurate? It's not a problem anymore because I know about this, but for most of my life when I'm coded PHP, I had no clue even about the existence of those functions, let alone the need to use them.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Is there any indentation tool for (la)tex?  I currently use TexShop under Mac OSX, so I can either use a TexShop plugin or a command line tool.

I'm looking for a LaTeX code sniffer and/or code beautifier, because I'm creating a CI server for my LaTeX books and I wanted a few things. :D


If the intention was to, as much as possible, shove the ADC output octets that were present in the camera right up the framebuffer and out the HDMI cable - possibly truncating LSBs, if possible discarding (or averaging) one of two green channels and simply mapping the three remaining pixels of a bayer quad to the rgb channels of a monitor pixel each (no advanced demosaicing) - ... how would one have, in general terms, to set up a camera, typical software (Rawtherapee, LR etc), and the computer?  I admit this question is half academic, but could help clarify the confusion about what is most unaltered in a digital workflow, and help with lens comparisons etc.

I know people use fancy software like Lightroom or Darktable to post-process their RAW files. But what if I don't? What does the file look like, just, y'know, RAW?


i recently used blender to create a butterfly knife. it looks normal until i export it   How i can fix this?

I modeled a logo in Blender and everything is clean.     When I export an OBJ and import it into Element 3d, a few extra edges have found their way into the model.    Any ideas on why this is happening? I have a feeling it's some setting within Element 3d but it could very well be a blender to OBJ issue.


In this bibliography, the title field of an entry of type @article is encased in quotation marks, and title field of an entry of type @book is typeset in italics.  How can I change that the title field of an entry of type @article is also written in italics and without " "?  \RequirePackage{filecontents} \begin{filecontents}{\jobname.bib}    @Article{Aili2010,       Title      = {Bioresponsive peptide-inorganic hybrid nanomaterials},       Author     = {Aili, Daniel},       Journal    = {Chem. Soc. Rev.},       Year       = {2010},       Volume     = {39},    }    @Book{Prodan2003,       Title      = {A Hybridization Model for the Plasmon Response of Complex Nanostructures},       Author     = {Prodan, E. and Radloff, C. and Halas, N. J. and Nordlander, P.},       Year       = {2003},    } \end{filecontents}  \documentclass{scrartcl} \usepackage[backend=biber,style=alphabetic,maxnames=10]{biblatex} \addbibresource{\jobname.bib}  \begin{document} Test.\cite{Prodan2003}\cite{Aili2010} \printbibliography \end{document}

I use BibTeX and biblatex to create a bibliography. In my BibTeX database I define a @inbook reference with author, title, year and booktitle. Now the problem is that the reference is rendered as:     Author (year): “Title”. In: BookTitle.   I need to remove the quotes around the title.  I already have a custom cite style file with some other definitions, but I did not find where to remove these quotes.


my ubuntu is showing me this error:  abhishek@abhishek-ThinkPad-R61:~$ youtube-dl -f worst http://www.youtube.com/watch?v=QGhx-u-c5Cg [youtube] Setting language WARNING: unable to set language: nonnumeric port: 'port_no' [youtube] QGhx-u-c5Cg: Downloading video webpage ERROR: unable to download video webpage: nonnumeric port: 'port_no' abhishek@abhishek-ThinkPad-R61:~$

This error occurred when using youtube-dl:  [youtube] 1234567890A: Downloading webpage [youtube] 1234567890A: Downloading video info webpage ERROR: 1234567890A: "token" parameter not in video info for unknown reason;    please report this issue on https://yt-dl.org/bug.  Make sure you are using the latest version; type youtube-dl -U to update.    Be sure to call youtube-dl with the --verbose flag and include its complete output.    I tried to uninstall youtube-dl and reinstall it, but this error reoccurred.


Let's say I've got a string with three strings looking like this:  String s = "[object1,object2,object3]";   How do I convert this to a String array which looks like this:  String[] ary = {"object1", "object2", "object3"};   Also mind that each string item (object1, object2 and object3) may also contain additional comma (,) characters.

Is there in the JDK or Jakarta Commons (or anywhere else) a method that can parse the output of Arrays.toString, at least for integer arrays?  int[] i = fromString(Arrays.toString(new int[] { 1, 2, 3} );


I would like to use the word only in my sentences. However, I am always confused how to use it correctly. For example:  The method of the author was only applied to a specific area. The method of the author considered only a specific type of food.  Are my sentences correct? Any help, please?

Which is grammatically correct?  I can only do so much in this time.  or  I can do only so much in this time.


I have a 320 GB HDD, and I want to migrate my Ubuntu system to a 60 GB SSD I bought.  I have an ext4 root partition and a swap partition. The root partition has 314 GB, but my files take up 50 GB, the rest is free space, so my partition is larger than the SSD, but my files can fit in it.  I have already partitioned the SSD with a 54 GB ext4 partition and a swap partition, now I only need to move my files to it.  What is the best approach here - using cp, dd, gparted, or something else?

My current situation is:   One hard disk Dual boot Ubuntu 11.04 and Windows 7. Partitions:  100MB Windows System thingy 144GB Main Windows 160GB Ubuntu 4GB Swap 12GB System Restore stuff    Now I want to install an 80GB SSD and move Ubuntu to it. AFAIK I need to:   Shrink the 160GB Ubuntu partition to 80GB Copy it over to the SSD Change fstab to mount the SSD as /   How do I do the second? And what do I need to do about Grub?


What is the meaning of Freddy's? Why did put apostrophe s at the end of the word Freddy? What is the grammar rule behind this?

In the following sentence, how would I indicate possession if the word "business'" were replaced by the name of the business: like "Fry's" or "Wendy's"?     Some business' employees are happy.   It seems strange to say that Wendy's employees are happy, since I'm referring to the business, and not just Wendy.


I've been given the function $$f(x)=\sum_{n=0}^{\infty}(2n+1)(2x)^{2n}$$ And I have to evaluate $f(1/4)$ so find the value of $$f(1/4)=\sum_{n=0}^{\infty}\frac{2n+1}{2^{2n}}$$ I would appreciate any help with this as I am pretty lost.

How can I evaluate $$\sum_{n=1}^\infty\frac{2n}{3^{n+1}}$$? I know the answer thanks to , but I'm more concerned with how I can derive that answer. It cites tests to prove that it is convergent, but my class has never learned these before. So I feel that there must be a simpler method.  In general, how can I evaluate $$\sum_{n=0}^\infty (n+1)x^n?$$


Is XTrap Safe? My little brother downloaded Microvolts surge from steam and got it. Is it a virus? Can it get me a virus? All I know that it is anti-cheat, but that's it. Will it add tracking cookies, or put a trojan on his computer? Anything bad about it?

I have recently installed  with the intention of trying it out, even though I'm not really an MMO person. Something in the game's aesthetic just really appeals to me.  While the gameplay videos I've seen looked decent, the installation experience itself had me questioning the game's credibility. The installer and subsequent launcher look slightly shady, with several suspicious windows popping up and disappearing.  When I finally got to launching the actual game, I suddenly saw the following icon before the game went full-screen:    Snooping around online, I discovered that this is some sort of cheat-prevention module called X-Trap, that is aimed to detect the following, amongst other things:        The user has modified game files   The user is running a 3rd party program that is not allowed   The user is modifying the program dynamically      While I understand why cheat prevention is important in such games, my instincts are to be highly suspicious of this module. This is exacerbated by the fact that I can't seem to find any official information about it.  So my question is, can I trust X-Trap not to:   Spy on me. Alter my computer in ways I am unaware of. Interfere with other programs. Do other bad things I can't necessarily think about.


Okay really confused about something here. Two questions.  First question is according to my compiler, string is always a size of 40 bytes. How is this possible when we can have more than 40 characters in a string and each character should be taking up 1 byte?  Second question: If I have a struct containing a string (40bytes) and an integer (4bytes), why is my resulting structure size 48 instead of 44? I can't figure out what is going on here.  Thanks if anyone knows/understands why i'm getting this behavior.      struct Employee //This struct is size 48 for some reason?     {         string name; //String takes up 40 bytes         int ID; //int takes up 4 bytes     };       struct Size8Struct //This struct is size 8 as expected     {         int ID;         int filler;     };       int main() {         cout << sizeof(Size8Struct) << endl; //returns 8 as expected         Employee Jim; Jim.ID=1; Jim.name="Jim";         cout << sizeof(Jim) << endl; //returns 48, why?          string test = "123456789012345678901234567890123456789012345678901234567890 test"; //How is it possible for this string to hold over 40 chars if it is only 40 bytes long?         cout << sizeof(test) << endl;     }

Why does the sizeof operator return a size larger for a structure than the total sizes of the structure's members?


I'm tasked with moving our SQL Server instance and system databases from the existing drive it's on to a new drive on the same server. I know I can stop the SQL Server service, literally move the instance and database files to the new drive and start the service again, but the drive is going to be mapped to a different letter.  I'm guessing I'll need to update the database file paths for the system databases to point to the new drive letter.  What else do I need to do to reconfigure the instance so that's pointing to the correct drive, to ensure it works properly when I start the service again?  Edit: It sounds like this Microsoft doc is pretty encompassing of what to do, especially from the system database perspective, but are there any other steps or gotchas I should be aware of from the instance perspective:   Note: I am unable to re-use the same drive letter for business reasons.

scenario:  one of my client was asked me to move entire program files folder from C:\ drive E:\ drive and change the all databases location to E:\ drive. They have copied entire program file folder through third party tool and pasted it on E:\ drive and they asked me to change path of databases and SQL installation to E:\ drive. Now how to change all databases paths and how to do this kind of activity? i know how to move system and user databases manually from one drive to another but i haven't face this king of scenario. Please suggest me how to do this task without any errors.


when I import OBJ file. The edge becomes 'strong'. some edges are good, but most of them are like this in picture.

There are red and pink edges on my mesh.  What do these colored edges mean? How can I use them?


I'm new to inequalities in mathematical induction and don't know how to proceed further. So far I was able to do this:  $V(1): 1≤1 \text{  true}$  $V(n): n!≤((n+1)/2)^n$  $V(n+1): (n+1)!≤((n+2)/2)^{(n+1)}$  and I've got : $(((n+1)/2)^n)\cdot(n+1)≤((n+2)/2)^{(n+1)}$ $((n+1)^n)n(n+1)≤((n+2)^n)((n/2)+1)$

I have to show $n! \leq \left( \frac{n+1}{2} \right)^n$ via induction.  This is where I am stuck:  $$\left( \frac{n+2}{2} \right)^{n+1}  \geq \dots \geq =2  \left( \frac{n+1}{2} \right)^{n+1} = \left( \frac{n+1}{2} \right)^n(n+1) \geq n!(n+1) = (n+1)! $$  I approached this from both sides and this is the closest I can get. I realize that $n+2$ on the left has to be bigger than $n+1$ on the right, but I do not know who to show that it overpowers the factor two I have from the right.  What could I do to fill the dots? Currently, I just have it without the dots, but I would be happier if I could back it up.


I have HP Dl120 Gen9 to install CentOS 7, I have tried to install CentOS 7 on Raid 0 (not too risky for test server) but apparently I had a problem booting it.  Next thing I did is to create a new array with Raid 5 (2.73 TB Usable in total of 4.00 TB). But still, when I installed CentOS 7, is still doesn't boot up.  How come it doesn't boot CentOS, thanks in advance for any tips.  Edit * There is no error message or any log that I could show off!

I'm trying to install CentOS 7 on a HP DL120 gen 9 server with a b140i controller. I have 4 1TB HDD setup in a raid 1+0 and the CentOS installer doesn't seem to recognize the logical drive created from the storage utility.  From my understanding i need some drivers for CentOS 7 to recognize the B140i controller. Also, the driver seems to be closed source by HP.  What is my approach here? Is there any other free linux OS that i can use on this server and that would recognize the raid controller?  Thank you.


Just a simple question.. I am using UTF-8 as standard in both my MySQL database and HTML file.. One thing that I don't understand is why a letter is shown differently in SQL than when I typed it. I am sure it should be placed the exact same way as I write it, when using UTF-8.  Is there a class or something that automatically keeps all posted data in UTF-8 and then posts it as it is?

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


I've checked each stick individually in the computer, by itself, to verify that the RAM was all in working condition.  I have 2 sticks of 4gb RAM and 2 sticks of 3gb RAM.  I'm not sure which are being detected and which aren't.  Any advice would be much appreciated.  system specs (AS SHOWN)  Windows Edition: Windows 7 Home Premium processor: AMD Athlon II X4 620 Processor 2.60GHz Installed Memory (RAM): 6.00GB (3.25GB usable) System Type: 32-bit Operating System  Everything I've seen related to the subject is in regards to the amount of usable RAM being less than the amount installed. This is not my main issue, I have 14GB of RAM (2 sticks 2X2G DDR3, 2 sticks 3x1G DDR3), and only 6GB is shown as installed, with only 3.25GB of that usable.

I recently upgraded my computer's RAM to 4 GB. My 32-bit Windows installation shows only 3574 MB of the memory. How can I make Windows use the full amount of RAM?


I'm installing Intercom () for customer engagement on my site. With the recommended installation the javascript snippet they gave would have my intercom app_id exposed in the page source.  May not be a big deal, but I was wondering if there was a better way where I could keep that hidden.

I want to make a JavaScript application that's not open source, and thus I wish to learn how to can obfuscate my JS code? Is this possible?


Let $G$ be a set with the operation $*$ such that:   $G$ is closed with respect to $*$ $*$ is asociative There exists an element $e \in G$ such that $e*x=x$ for all $x\in G$ Given $x \in G$, there exists $y\in G$ such that $y*x=e$   The axioms of closure and asociativity are satisfied by the hypotesis 1 and 2. Now it is left to prove that $x*e=x$ and $x*y=e$ to conclude $G$ is a group. I've made some sustitutions to try to get the commutative property on those produts but I don't get a way to achieve it. These set of suppositions are then stronger than the group definition as they can be deduced from these ones right? What shoud I compute to prove $G$ is a group?

Let $G$ be a set with a binary operation *, associating to each pair of elements $x$ and $y$ of $G$ a third element $x*y$ of $G$. Suppose that the following properties are satisfied:   $(x*y)*z = x*(y*z)$ for all elements $x$, $y$, and $z$ of $G$ (the Associative Law); there exists an element $e$ of $G$ such that $e*x = x$ for all elements $x$ of $G$; for each element $x$ of $G$ there exists an element $x'$ of $G$ satisfying $x'*x = e$.   How to prove  i. $x*e=x$ and  ii. $x*x'=e$,  so that $G$ is a group?


I'm unfamiliar with C++, but something that I am trying to build requires the C++ version to be C++ 20 (it uses some features that only cpp 20 has apparently). I believe my current version is lower than that (C++ 17 or something along that line). How can I update my version of C++ to the newest version? I am on Ubuntu 18.04.3 LTS.

I want to compile my program with the latest version of gcc.  Ubuntu 14.04 comes with gcc 4.8.2, however there's 4.9.0 available, moreover, I see that it is available as a package: . I tried to install it  sudo apt-get install gcc-4.9   but it says  Reading package lists... Done Building dependency tree        Reading state information... Done Note, selecting 'gcc-4.9-base' for regex 'gcc-4.9' gcc-4.9-base is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   Looks like it is already installed, just not as the default one? How do I utilize it to build my program?


I am not able to understand the exact meaning of bias. The least squares is said to give us unbiased estimates during linear regression but still we refer linear regression to have a high bias because of its assumption ?

I'm struggling to grasp the concept of bias in the context of linear regression analysis.    What is the mathematical definition of bias? What exactly is biased and why/how? Illustrative example?


In the future that Star Trek depicts, many nations have changed, such as Africa becoming the United States of Africa. Have any countries fallen victim to this? Options include assimilation into other countries, destruction during the third world war, etc.

Is there a map of Earth somewhere that shows the various countries that exist during the 24th century? I know it's called United Earth, but I'd imagine it's still divided up into various countries. The ones I've heard mention of are USA, Canada, and France but what others exist at that time?


When I use Task Manager to see how much memory is being used, it says 76% memory. I have 8GB of ram. However when I add up all the memory being used by all the different processes, it doesn't add up to 8GB.  As seen in the gif above, the memory usage shown by each program in Task Manager does not add up to 6GB of the memory I have out of 8GB. If around 75% of memory is used, then the memory usage of all the processes, should add up to 6GB, right? What is going on and how do I fix it? I see that similar questions have been asked, but the questions do not fit my use case as they are asking different things to what my question is asking and their answers are not helpful.

The new Task Manager has a great UI in windows 8, however, there are some discrepancies in the data I can not account for:  Machine: 8 GB of total ram. (This is a physical machine, not a virtual)  The processes tab shows 45% of Memory utilized.  The listed process do not add up to 3.5 GB of RAM, but instead add up to 0.948 GB. There is no "processes for all users" option.   The performance Tab Shows:   In use : 3.6 GB Available: 4.4 GB Committed : 4.1 /9.2 GB  Cached: 3.7 GB Paged Pool: 376 MB Non-paged pool: 135 MB  My reading of this says I have ALOT of "cloaked" processes running some where eating my ram.  How do I interpret this data and how do I verify it?


Doesn't tell you how to use them or equip them or anything (without auto equip) Xbox1

Now that I'm level 2 I need to know how to auto equip mods till I figure out how they work. (Xbox1) or even equip mods in the first place.


Good morning to everybody. I have a problem because all of a sudden my latex file is not uploading citations any more. I created a .bib file with citations manually and it was working untill recently.  I think the .bib file is fine, there just has to be some reason why the main latex file cannot link to .bib file anymore... One probably stupid thing that I did has been to erase all the AUX, TOC ecc... Files that the system auto generates... Could that be the reason? I don't know how to solve this. Thank you for your help, Nicola.  This is the main file text:  \documentclass[12pt,twoside,openright]{book}  % default square logo   \usepackage[english]{babel} \usepackage{amssymb} \usepackage{amsmath} \usepackage{breqn} \usepackage[section]{placeins} \usepackage{graphicx} \usepackage{caption} \usepackage[utopia]{quotchap} \usepackage[sort&compress]{natbib} \usepackage{fancyhdr} \setlength{\headheight}{15.2pt} \usepackage{lipsum} \usepackage[svgnames]{xcolor} \usepackage{hyperref} \usepackage{titlesec} \usepackage{setspace} \usepackage{layout} \usepackage{textcase} %\usepackage[margin=2cm]{geometry} \usepackage{chemformula} \usepackage{physics} \usepackage{siunitx} \usepackage{float} \usepackage{comment}       \hypersetup{colorlinks=true, pdfstartview=foo, linkcolor=black, citecolor=black, plainpages=false, pdfpagelabels=true, urlcolor=blue} \usepackage[all]{hypcap}  \captionsetup[figure]{font=small,labelfont=bf}   \title{Manipulation of SPEs}   %note \\[1ex] is a line break in the title  \author{Nicola Palombo Blascetta}             %your name   \usepackage{titlesec}  \newcommand{\chapfnt}{\fontsize{25}{19}} \newcommand{\secfnt}{\fontsize{12}{17}} \newcommand{\ssecfnt}{\fontsize{12}{14}}  \titleformat{\chapter}[display] {\normalfont\chapfnt\bfseries} {\Large\chaptertitlename\ \thechapter}{10pt}{\chapfnt} \titlespacing*{\chapter}{0pt}{0pt}{10pt} %[\vspace{1ex}\titlerule] %line between title and text \def\baselinestretch{2}    \titleformat{\section} {\normalfont\fontsize{15pt}{14pt}\selectfont\bfseries}{\thesection}{1em}{}   \titleformat{\subsection} %{\normalfont\ssecfnt\bfseries}{\thesubsection}{1em}{} {\normalfont\fontsize{13pt}{14pt}\selectfont\bfseries}{\thesection}{1em}{}    %headers and footers \pagestyle{fancy} \fancyhf{} \fancyhead[RO]{{\fontsize{8}{20} \selectfont\rightmark}} \fancyhead[LE]{{\fontsize{8}{20} \selectfont\leftmark}} \cfoot{\thepage}   \renewcommand{\headrulewidth}{0.4pt} \renewcommand{\footrulewidth}{0.0pt}   %offset at top of page %\voffset = 0.7 cm %set margins total is nortmally 1.87580  \addtolength{\oddsidemargin}{-0.5cm} \addtolength{\evensidemargin}{-0.5cm}  \addtolength{\textwidth}{1cm}  \addtolength{\topmargin}{-0.5cm} \addtolength{\textheight}{1cm}    \begin{document}          \baselineskip=18pt plus1pt      \setcounter{secnumdepth}{3}     \setcounter{tocdepth}{3}       \maketitle                  % create a title page from the preamble info    \include{Abstract}              \tableofcontents            % generate and include a table of contents            \include{Intro/Chapter1}      \include{chapter2/Chapter2}      \include{chapter3/Chapter3}      \include{chapter4/Chapter4}      \include{chapter5/Chapter5}      \include{Conclusions}     \include{ChapterPublications}     \include{ChapterAcknowledgements}      \addcontentsline{toc}{chapter}{Bibliography}       \bibliographystyle{unsrt}     \bibliography{References}          \end{document}

I've browsed the forums and found a number of posts that have addressed this issue, but none of the solutions seem to work for me. I have the following script that I just copied from the bibtex home page to get familiar with it. Instead of the citation number I get a question mark. I compile using Latex+Bibtex+Latex+Latex+PDFLatex+ViewPDF just as has been previously suggested and the problem persists.   \documentclass[11pt]{article} \usepackage{cite}  \begin{document}  \title{My Article} \author{Nobody Jr.} \date{Today} \maketitle  Blablabla said Nobody ~\cite{Nobody06}.  \bibliography{mybib} \bibliographystyle{plain} \end{document}   My bibliography (Bib.bbl)  @misc{ Nobody06, author = "Nobody Jr", title = "My Article", year = "2006" }    Looking at previous posts one thing that is concerning is that my .bbl looks empty as shown below. Further, I don't have a .blg  \begin{thebibliography}{}  \end{thebibliography}


I have a distribution of the form $\exp(-\exp(-x^2))$. Is this a known family of distributions. Otherwise how would you find/approximate the normalising constant. The domain is $x \in (-\infty,\infty) $  Note: I want to do this without sampling.

What would the normalising  constant be of the following, or atleast an approximation? I would like to avoid sampling.  $$f(\theta)=\exp(-k_1e^{-k_2\theta^2}-\theta^2)\qquad\theta\in(-\infty,\infty), \quad k_1,k_2>0$$  In the event that its not possible, what would be a valid polynomial lower bound on $\log(f(\theta))$, that would take into account $k_1$  For anyone, who is interested, I end up with this expresssion because I place a Gaussian prior over (a squared exponential) kernel parameters, and trying to use variational bayes (hence, a lower bound).


From two weeks I'm thinking about performing statistics in my LaTeX document to improve the way I write (and for curiosity). I would like to retrieve the distribution of words I'm using most, and other things like that. I know there are many tools to do that, but I'm not sure which is the easiest way to do it in my TeX document.

I would like to convert a large LaTeX project (i.e. spanning multiple files) into plain text. The purpose is generation of statistics, so representing mathematics is not an issue. In fact, all mathematics is ideally ignored.  I have found  but could not get it to run. It seems unfinished, but is exactly what I am looking for otherwise.


I've created a cube mesh. I've changed its dimensions and from the top face of the mesh, I've extruded. However, whenever I move the top face of the extrusion, it pulls the whole object and not just the extrusion I made like it has with other objects I've extruded from. Why is it acting differently?   Nvm, found out. Disabled soft-selection that I must have enabled by accident.

My problem is that I sometimes lose the ability to independently translate or otherwise transform any parts of a single mesh. If I try, for example, to just translate several faces, edges, or vertices, then the entire mesh will stretch and displace itself in order to follow the translation. Or, alternatively, if I try to translate just one face then the whole mesh will move as if I'm translating in Object Mode.  I'm not really sure I know how to describe this problem properly. I don't even know how to reliably reproduce it. It seems to happen to any given mesh at random, and it doesn't stop happening to that mesh unless I delete and remake it.  I assume that I must be doing something wrong to cause this to happen. Does anyone have any ideas? Thanks.


It seems that if I write too many lines of equation within an align environment after some text, that environment will not span more than one pages, and leave blank at the bottom half of the previous page. How can I make it span more than one pages? Thanks.

I do have a longer paper. In one chapter I got several multiline equations, which I wrote using the align environment from amsmath-package. Actually those are quite long computations which should break anywhere for avoiding to much empty space on a page.  I want to use something like \allowdisplaybreaks, which does exactly what I want. The problem is, that I do not want to allow displaybreaks anywhere else in the document, where I have no control about it. I tried to use \allowdisplaybreaks directly before \begin{align}, hoping it would only apply on the next following align-enviroment. But it applies to every align-environment later in the text.  Is there any way to "stop" the command again?  And yes, I could use \displaybreak for single breaks, but I had to use it in many equations and I needed to put it in every single line, since the pagebreak should move, if I add a few more lines anywhere in the chapter.   Thanks for your help, Greyfox


I have a quick question about the difference between the two concepts in the title.  The question is basically ex.6 (b) in Hatcher's book titled "Algebraic Topology". Let $X$ be the subspace of $R^2$ consisting of the horizontal segment $[0,1] \times \{0\}$ together with the vertical segments $\{r\} \times  [0,1-r]$ for $r$ a rational number in $[0,1]$. Now let $Y$ be the space that is the union of an infinite number of copies of $X$ arranged in a zig zag formation. See below -     Now my question is why can't one deformation retract $Y$ to a point in the darkened zig zag line? Surely the darkened zig zag line is homeomorphic to $\mathbb{R}$, which is deformation retractable to a point, and each of the vertical lines of each copy of $X$ deformation retracts to its segment of the zig zag line! I must be missing something here as one has to prove that $Y$ does not deformation retract to any point!

I am starting to read Hatcher's book on Algebraic Topology, and I am a little stuck with exercise 6(c) in Chapter $0$. Unfortunately a picture is involved so it doesn't quite make sense for me to repeat it here - but I'll do it anyways (maybe it helps)     Let $Z$ be the zigzag subspace of $Y$ homeomorphic to $\mathbb{R}$ indicated by the heavier line in the picture:       Show there is a deformation retraction in the weak sense of $Y$ onto $Z$, but no true deformation retraction."   Now the definition for deformation retraction and weak deformation retraction as as follows:  We say that $f: X \to X$ is a deformation retraction of a space $X$ onto a subspace $A \subset X$ if there exists a family of maps $f_t : X \to X$ with $t \in [0,1]$ such that $f_0 = \mathbb{1}$ (the identity) and $f_1 (X) = A$ and also $f_t$ restricts to the identity on $A$ for each $t$.   A weak deformation retraction is almost the same, only that we now relax the conditions $f_1(X) = A$ to $f_1 \subset A$ and, for each $t \in [0,1]$ we require that $f_t(A) \subset A$.  Hence, as far as I understand the question and the concepts involved, I need to show that basically no map can be constructed such that the bold zigzag - line stays put while the thin lines retract to the bold line over a finite time interval $0 \leq t \leq 1$. However, I should be able to show that I can pull the thin lines continously onto the thick line, provided I am allowed to move points on the zigzag line .. is that correct ?  Now, the problem is I can't see why I shouldn't be able to do the former, given that I could find a weak deformation retract. Any help would be great!


I am currently trying to make an updating scoreboard that tracks a players HP and current kills but I am not having much luck. I have tried many different things and been stuck for well over 2 hours now. The problem lies when trying to get the players HP and kills. The error below is that of the kills issue, but another issue is the HP returning null hence the Unhandled Exception. Here is there error:    Here is the code: Line 144 - 162 of Main.java  @SuppressWarnings("deprecation") public void run(String arena){     for(String key : Handler.playerMap.keySet()){         if (Handler.playerMap.get(key).contains(arena)){             Player pt = Bukkit.getPlayer(key);             String p = pt.getDisplayName();             ScoreboardManager manager = Bukkit.getScoreboardManager();             Scoreboard board = manager.getNewScoreboard();             Objective objective = board.registerNewObjective("test", "dummy");             objective.setDisplaySlot(DisplaySlot.SIDEBAR);             objective.setDisplayName(ChatColor.AQUA + "Wave: " );             Score score = objective.getScore(ChatColor.GREEN + "" + pt.getHealth() + ChatColor.WHITE + p + ChatColor.AQUA);             int kills = PlayerHandler.kills.get(p);             score.setScore(kills);             int pcheck = 0;   Can anybody tell me what the problem is? Thank you in advance for any comments.

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 left unopened pack of lamb burgers to thaw on the counter for 2-3 hours, if I cook them thoroughly should they still be safe to eat? Please advise, haste is appreciated.

If I left food out of the refrigerator for some period of time, is it still safe? If I left it out too long, can I salvage it by cooking it more?


I'm writing a simple method that takes grades as input from the user and calculates the Grade Point Average. Here is my code:   public static double calculateGPA(){    Scanner in = new Scanner(System.in);     double totalGradePoints = 0; // total grade points    int numClasses = 0; // total classes completed    boolean doneInput = false; // returns true when use is done inputting grades     System.out.println("Enter all your grades (A,B,C,D,F) and enter 'done' if you are done entering your grades.");      while (!doneInput) {            String grade = in.next();        if (grade == "A") {          totalGradePoints += 4;          numClasses++;       } else if (grade == "B") {          totalGradePoints += 3;          numClasses++;       } else if(grade == "C") {          totalGradePoints += 2;          numClasses++;       } else if(grade == "D") {          totalGradePoints += 1;          numClasses++;       } else if(grade == "F") {          numClasses++;       } else {          doneInput = true;       } //end if - else-if - else statement    }//end while loop    double unwtGPA = (totalGradePoints/numClasses);    return unwtGPA; }   When I tested the method, I was only able to input one grade and none of the variables incremented, can somebody tell me what's wrong with the code?

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


if $\sum_{n=1}^\infty a_n$ is a convergent series of positive numbers,   and if $\{ a_{n_i} \}$ is a subsequence of $\{ a_n \}$ , ( n , i are Natural numbers ),  prove $\sum_{i=1}^\infty a_{n_i}$ converges.  My idea is: since $\sum_{n=1}^\infty a_n$ converges , then $\{ a_n \}$ converges ( to zero ), hence its subsequence $\{ a_{n_i} \}$ converges ( to zero ).  Now I want to show the sequence of partial sums of $\{ a_{n_i} \}$ is bounded, to prove the series $\sum_{i=1}^\infty a_{n_i}$ is convergent.  I do not know how to show this. or is my idea correct in the first place. I appreciate any help.

Let $\sum_{k=1}^\infty a_k$ be a convergent series with nonnegative terms and let $a_{n_k}$ be a subsequence of {$a_k$}. Prove that the series $\sum_{k=1}^\infty a_{n_k}$ converges.  I am having trouble figuring out how to prove this and am pretty lost.  My very first idea was to try and prove that it is increasing but don't know where I would take it from there. Any help would be appreciated!


Why does $\lim\limits_{x\to\infty}(x!)^{1/x}\neq 1?$  As far as I know, anything to the power of $0$ is $1$.  We have a factorial raised to $1/\infty=0$, but the limit is not $1$? I don't even know what the limit is. But it seems like infinity? Why is this?

Here's the problem... $$\lim\limits_{x\to \infty}\ (x!)^{1/x}$$  I've deduced the answer to this is $\infty$, but haven't exactly shown that.  I'm getting $\infty^0$, so did both tricks where you change it to  $$\exp\left({\lim_{x\to\infty}} \frac{1/x}{1/\ln(x!)}\right) = \exp\left(\frac{0}{0}\right)$$ And $$\exp\left({\lim_{x\to\infty}} \frac{\ln(x!)}{1/(1/x)}\right) = \exp\left(\frac{\infty}{\infty}\right)$$  And for both of which, I need to do L'Hospital on this $\ln(x!)$ which I haven't the slightest idea how to do... Any suggestions that don't include Stirling's Approximation? My prof eluded to this being out of the question unless we were going to prove Stirling's first


Normally I can put in a search like this  javascript   However, what if I want to restrict the results to only questions and answers that I have voted on? Is this possible?

Related posts:    These posts are different from mine in that they merely ask for the "votes" tab back or ask if it is at all possible to get such information, while I propose how to implement this as a search feature. Background I recently found myself facing a problem very similar to one that I had solved before. I remembered that I found the solution on SO and I remembered upvoting the post containing the solution. I wasn't able to find that particular post by just searching with relevant keywords. It would have been nice if I could search only among the questions I have voted on. I searched on meta and found that there had been a tab for looking at what you've voted on, but that it was removed due to lack of interest. This is understandable, since just listing the hundreds/thousands of posts you've voted on isn't particularly useful. Proposal What I want is to be able to search for posts I've voted on similarly to the way I'm able to search on my posts within a specific tag. For instance: user:310121 [iphone] apple  This will return all my posts tagged iPhone, where I mention Apple. This is brilliant. This is just how I want search to work. Now what I want to do is to extend this to include votes. The exact syntax isn't relevant, but I had to make one up to show you what I mean: To show all posts you've voted on: user:310121 {votes}  To show all posts you've upvoted: user:310121 {upvotes}  To show all posts you've downvoted: user:310121 {downvotes}  You could probably omit the the user part, since you're only allowed to see your own votes. (Unless it's desirable to be able to look at other peoples votes. Maybe you should be allowed to do this if you have enough rep? Well, that's another discussion.) I guess that even if you're allowed to see other peoples votes it would make sense to display your own votes if the user part is omitted. So in my case I could have done the following search and found the post I was looking for: {upvotes} keyword  Lastly I just want to suggest that clicking on your vote count will work just like clicking on a tag. If I click on a tag in my profile the following search will be done: user:310121 [tag]  So if I click on my upvote count the following search should be made: user:310121 {upvotes}  The same goes for downvotes: user:310121 {downvotes}  This would be a very useful feature and it wouldn't be intrusive in any way. The users that don't care for this feature might never know that it's there. And just for the record the favorite system doesn't replace this feature.


I'm having trouble determining the convergence of the series: $$ \sum_{k=1}^{\infty}\sqrt k - 2\sqrt {k + 1} + \sqrt {k + 2}  $$  I am thinking it doesn't converge and since neither the root test or $$|\frac{a_{k+1}}{a_{k}}|$$ seemed to work for me I would have to use a comparing test  Keep in mind I am not allowed to actually calculate what it converges to.

I am facing a problem, where I have to find the partial sum of a sequence/sum and with that, the infinite sum of the sequence.  $\sum_{k=1}^{\infty}\sqrt k - 2\sqrt {k + 1} + \sqrt {k + 2} $   The problem here is that I don't know how to proceed. I would be thankful if someone would steer me in the right direction.


This is the first time I'm storing data as a bitmap in a database, and was wondering how I should be storing it. For example, if I have four options:  colors = ['red', 'yellow', 'blue', 'green']   And the data is structured like this:  id      name        favorite_colors 1       'tom'       ['yellow', 'green']   I would like to store the favorite colors as a bitmap, for example, 0101 (red=0, yellow=1, blue=0, green=1).  What would be the correct way to store this?  For example, as a number?  id      name       favorite_colors 1       'tom'      5   -- field type = UNSIGNED INT   Or as raw binary?  id      name       favorite_colors 1       'tom'      b'0101'  -- what type would this be stored as?

I have a web-based application that notifies users of activity on the site via email. Users can choose which kinds of notifcations they want to receive. So far there are about 10 different options (each one is a true/false).  I'm currently storing this in one varchar field as a 0 or 1 separated by commas. For example: 1,0,0,0,1,1,1,1,0,0  This works but it's difficult to add new notification flags and keep track of which flag belongs to which notification. Is there an accepted standard for doing this? I was thinking of adding another table with a column for each notification type. Then I can add new columns if I need, but I'm not sure how efficient this is.  Thanks in advance!


I have gone through the below link which says that u-boot support three type of flash technology     1.Nand 2.NOR 3.SPI Serial Flash  I would want to know why SPI is choosen to be used as flash devices not I2C .  Why can't we have I2C based flash technology?

What tradeoffs should I consider when deciding to use an SPI or I2C interface?  This accelerometer/gyro breakout board is available in two models, one for each interface.  Would either one be easier to integrate into an Arduino project?


Although it seems intuitive, I haven't found proof of this fact in my textbooks from a purely mathematical standpoint. I was wondering if anybody knows of a particularly elegant proof of this fact, and if so would they be kind enough to share a link?

In every derivation of Kepler's Laws that I have seen, we assume that the sun is stationary. However, in other places I have read that celestial bodies move about their barycentre (center of mass). So are planets actually moving in elliptical orbits around the Sun or do they move in circular orbits around their center of mass?


How do you see and adjust partitions on a hard drive in Ubuntu 14.04? I want to add Openelec to my second partition.

I found a 6 GB IDE HDD in my basement. I want to plug it in and see what might be on it. The drive seems to be recognized in BIOS.   I can't find it in Ubuntu to view files, and Ubuntu is the only OS on that particular computer. I was wondering if Ubuntu has an equivalent to the Windows feature "My Computer", which lists all available drives/storage devices. Typically, My Computer shows C:, which can be opened to view all of your directories and files. At this point, it is very similar to Ubuntu's Home Folder.  How to view/select all available partitions of that drive or all available HDD's without formatting or tampering with the contents in any way?