How to save a GIF with transparency without it creating white blobs around glow? Open for other solutions!
What formats supporting animation are suitable for the web?
How much longer will my 10 year old frame last? $\sqrt{c+\sqrt{c+\sqrt{c+\cdots}}}$, or the limit of the sequence $x_{n+1} = \sqrt{c+x_n}$ HTTP and HTTPS impacts on SEO I have a website http://www.domain_1.com/ hosted in a shared webserver.  I have used SSL for another website https://www.domain_2.com/ on the same server.  Due to some technical limitations (single IP), if you try https://www.domain_1.com, browser will show the same domain_2 website. But this is not a concern for me.  Question: will this scnario impact SEO of domain_1 (non-HTTPS) site? I understand what the game already tells you in the general sense... it changes enemy damage, resistances, and chance of legendary monsters appearing.  But, specifically, how does the difficulty level affect the game? Is going from Normal to Hard a 5% increase in damage? 50%? 200%? Are there any additional things changed that aren't mentioned. Does Survival mode add any extra mechanics, or is it just even bigger numbers than Very Hard? I have a C++ library that provides various classes for managing data.  I have the source code for the library.  I want to extend the C++ API to support C function calls so that the library can be used with C code and C++ code at the same time.  I'm using GNU tool chain (gcc, glibc, etc), so language and architecture support are not an issue.  Are there any reasons why this is technically not possible?  Are there any gotcha's that I need to watch out for?  Are there resources, example code and/or documentation available regarding this?    Some other things that I have found out:   Use the following to wrap your C++ headers that need to be used by C code.     #ifdef __cplusplus extern "C" {   #endif   //   // Code goes here ...   //   #ifdef __cplusplus   } // extern "C"   #endif    Keep "real" C++ interfaces in separate header files that are not included by C.  Think  here.  Using #ifndef __cplusplus #error stuff helps here to detect any craziness. Careful of C++ identifiers as names in C code Enums varying in size between C and C++ compilers.  Probably not an issue if you're using GNU tool chain, but still, be careful. For structs follow the following form so that C does not get confused.  typedef struct X { ... } X  Then use pointers for passing around C++ objects, they just have to be declared in C as struct X where X is the C++ object.   All of this is courtesy of a friend who's a wizard at C++. How do I force TeX to completely use the 1st column? How do I force TeX to completely use the 1st column before writing to the second column?  Right now I dont have enough content to fill one whole page. So the left and right columns are equally filled, leaving 25% symmetrical empty page at bottom. How do I fill the left column first, and then the right?  \documentclass{article}  \usepackage{multicol} \usepackage[scale=0.9]{geometry} \usepackage{amssymb} \renewcommand{\labelitemi}{\tiny$\blacksquare$} \begin{document} \begin{multicols}{2}      %lots of text goes here  \end{multicols} \end{document} $X$ and $Y$ are independent rv having pdf $f(t)=\frac{1}{\pi} \frac{1}{1+t^2}$ determine pdf of $Z=\frac{X+Y}{3}$ On the commutative property of multiplication (domain of integers, possibly reals) $ab = ba$  This is, inherently, true. Some texts drop it like an axiom without any justification. But I'm a bit curious where it stems from or basically why/how it works. If anyone could enlighten me a bit further, I'd be most grateful. Peano axioms? From set theory? Help.  What bugs me with this definition is it's real world "application":  Let's say I have a power output of 5 W ( $kg\cdot m^2 \cdot s^{-3}$) and I want 30% of that power output (to have some units and natural context).  Naturally, 30% is 30 1/100 (% is the unit). For simplicity, let's express that as:  $30$%$ = 30/100 = 3/10 = 3d$ where $d = 1/10$, a simpler unit (because %W would look... Wrong?).  So 30% of power is then $5 W \cdot 3d$, and we can force it to "make sense" if we associate d with W or basically scale the unit of power by d (which is intuitively understood as being 10 times smaller then the output of 1 W) $dW$. And we want to scale these 5 units of $dW$ three times.  $5 dW \cdot 3$  But the commutative property says it is the same as scaling 3 units of $dW$ 5 times or:  $3 dW \cdot 5$  And the result is the same. This is the bit that hurts my head, the fact it is the same. I try to interpret the same as, for example 50 J of work, it's either applying 50 N over 1 m of distance or 1 N over 50 m of distance.    Down here is additional stuff I think I have (you don't have to read it if you know how to answer immediately). I don't claim it's correct, if anyone parses this information, feel free to correct me.  $m\sum\limits_{i=1}^{n}{1} = n\sum\limits_{i=1}^{m}{1}$  This is how I've been trying to break it down, as it is repeated addition. It is repeated $n$ times and multiplied by $m$, and reverse on the right side. There is $x = m - n$, so when I multiply $n$ $m$ times, each repeated addition of $n$ lacks exactly $x$ to $m$.  $mn = nm$  $x = m-n$  $m(m-x) = (m-x)m$  $m^2 - mx = m^2 - mx$  $ true $  And yes, sadly, I realise that I am using the very property I'm trying to prove ($xm$ shifted as $mx$ on the right-hand side.)  And it even calls in the distributive property of multiplication over addition which I derive (for myself, informally) from the very nature of multiplication and the way we "process" numbers:  For example, number $55$ times $2$  $55 = 5 \cdot 10^1 + 5 \cdot 10^0 = 5 \cdot 10 + 5 \cdot 1$  $(5 \cdot 10 + 5 \cdot 1) \cdot 2$  This is the basis of our positional notation which appends digits of varying orders of magnitude or units together in a way it makes "sense". Each one is b times bigger than the one to the right. Basic stuff. It is why I expressed 10 and 1 explicitly, those are what I consider units in this case.  Now, from the definition of multiplication, which is at its heart just repeated addition, it is truly the same if you add together $2$ $50$ times and then again $5$ times or "all at once" (figuratively, we are always doing the former mentally) $2$ $55$ times.  That added together gives 110, which is true.  To me, the distributive property (in case of integer multiplication) is a repercussion of the very definition of multiplication which is repeated addition (evading strict concepts). I am not certain whether this is a good way to look at it. I just watched a TV show and the guy says:     I ain't trying to fight with nobody with a baby.   So here, I can't understand the "nobody" since it make no sense to me, but it sounds like anybody, and if it's "I ain't trying to fight with anybody with a baby." that makes sense to me. ..and I don't mean finding out why it doesn't compile, I mean serious debugging: breakpoints, figuring out value of variables at a given moment during run/compile, stepping, examining a stack (is there one?), etc. All the things that we take for granted when debugging a "real" programming language. Since TeX is "turing-complete", I would like to be able to really see what is going on internally.   I'm guessing that a GUI interface for the debugger would be too much to ask, but if it exists, I'd love to hear about it. Looking for a book, wormhole, space ship Crash landing From what I remember of the book:   A spaceship goes through a wormhole (I think) and crash lands on a planet They salvage what they can from the ship and build a castle on a mountain, cutting the stone with the lasers from the crashed ship The crew develop some sort of powers, the captain (She) seems to develop some sort of Precognition The planet's inhabitants where men rule and women are second class citizens Some women escape to the crew's castle so they can be equal citizens After they build the castle the crew fight the inhabitants the that came to attack them   What is the name of this book? Picking a $\delta$ for a convenient $\varepsilon$? I'm studying some proofs in a book from the library  and  unlike my own book, it doesn't prove by showing that a certain expression is striclty less than $\varepsilon$ (given an  appropiate $\delta$ and $\vert x-a\vert &lt; \delta$, etc). Instead, it shows that it's less than some expression involving $\varepsilon$.   E.g. Given $\varepsilon &gt; 0$, we can pick a $\delta &gt; 0$ so $|f(x) - g(a)| &lt;  \text{insert stuff} &lt; k \cdot \varepsilon$ when $|x-a| &lt; \delta$, and thus $f(x) - g(a) \to 0 $ when $x \rightarrow a$.  How does this make sense formally? (Intuitively, I am convinced.)  I don't have much experience with $\varepsilon$-$\delta$ -proofs, so I might be missing something obvious. I must have a blind spot, but I cannot find what it is.   I made a small python script that removes VLC from the sound menu. It runs perfectly in any way I run it from the terminal or from a launcher or whatever you can think of.   What the script actually does is nothing more than get the get the current settings:  gsettings get com.canonical.indicator.sound interested-media-players   edit the list, and set the changed list by:  gsettings set com.canonical.indicator.sound interested-media-players "['newlist']"   These commands are executed by a python script,. However, when run from a cronjob (crontab -e) only the gsettings - get - part works, but not the gsettings - set - section. That the get section works fine with cron, I checked by making the script write data (the original as well as the edited) to an external file.  Not a python problem  To see if the problem is related to python code, I created a bash script that applies a changed sound menu items list. The story is the same: the bash script runs fine from the command line or a launcher, not from cron, while any other command in the same script would run fine. Also, if I add any command at the end of the script below, it works fine and it looks like the script is satisfied with its own work.  Why is the gsettings set command not working when initiated from cron?  This is the script:  #!/usr/bin/python3 import subprocess  def read_soundmenu():     # read the current launcher contents     get_menuitems = subprocess.Popen([         "gsettings", "get", "com.canonical.indicator.sound", "interested-media-players"         ], stdout=subprocess.PIPE)     return eval((get_menuitems.communicate()[0].decode("utf-8")))  def set_current_menu(current_list): # this takes no effect from cron     # preparing subprocess command string     current_list = str(current_list).replace(", ", ",")     subprocess.Popen([         "gsettings", "set", "com.canonical.indicator.sound", "interested-media-players",         current_list,         ])  current_list = read_soundmenu() for item in current_list:     if item == "vlc.desktop":         current_list.remove(item) set_current_menu(current_list) 64 bit enum in C++? Is there a way to have a 64 bit enum in C++?  Whilst refactoring some code I came across bunch of #defines which would be better as an enum, but being greater than 32 bit causes the compiler to error.  For some reason I thought the following might work:  enum MY_ENUM : unsigned __int64   {       LARGE_VALUE = 0x1000000000000000,   }; How can one prove that $\lim_{n \to \infty}a^{1/n}=1$ for every $a>0$? Proving that for a smooth function if $f(\frac 1 k)=0 :\forall k\in \mathbb N$ then $f(x)=0 :\forall x\in[-1,1]$ Is Java "pass-by-reference" or "pass-by-value"? I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation? Can there be temperature inside of a massive Black Hole? Can I stop 100% Width Text Boxes from extending beyond their containers? Lets say I have a text box that I want to fill a whole line. I would give it a style like this:  input.wide {display:block; width: 100%}   This causes problems because the width is based on the content of the text box. Text boxes have margin, borders, &amp; padding by default, which makes a 100% width text box larger than its container.  For example, here on the right:    Is there any way to make a text box fill the width of its container without expanding beyond it?  Here is some example HTML to show what I mean:  &lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt; &lt;html xmlns="http://www.w3.org/1999/xhtml" &gt; &lt;head&gt;     &lt;title&gt;Untitled Page&lt;/title&gt;     &lt;style type="text/css"&gt;         #outer{border: 1px solid #000; width: 320px; margin: 0px;padding:0px}         #inner{margin: 20px; padding: 20px; background: #999;border: 1px solid #000;}         input.wide {display:block; margin: 0px}         input.normal {display:block; float: right}     &lt;/style&gt; &lt;/head&gt; &lt;body&gt;     &lt;div id="outer"&gt;         &lt;div id="inner"&gt;             &lt;input type="text" class="wide" /&gt;             &lt;input type="text" class="normal" /&gt;             &lt;div style="clear:both;"&gt;&lt;/div&gt;         &lt;/div&gt;     &lt;/div&gt; &lt;/body&gt; &lt;/html&gt;   If this is run, you can see by looking at the "normal" text box that the "wide" text box is sticking out beyond the container. The "normal" text box floats to the actual edge of the container. I'm trying to make the "wide" text box fill its container, without expanding beyond edge like the "normal" text box is. Do the automatic success and failure rules apply to skill checks? We had a rule check tonight that we couldn't answer. On the Pathfinder wiki I could only find info on natural 20s and 1s in regards to attack rolls and saves in combat.  Do they also apply to skill checks?