Why is sudo colourless when user is colourful for `ls` command?
Aliases not available when using sudo
Let $C_k$ be the set obtained in the $k-$th stage of building the Cantor set, where  $$C_1=[0,\frac{1}{3}]\cup[\frac{1}{3},\frac{2}{3}]$$  $$C_2=[0,\frac{1}{9}]\cup[\frac{2}{9},\frac{1}{3}]\cup[\frac{2}{3},\frac{7}{9}]\cup[\frac{8}{9},1]$$  $$\dots$$  So we have   $$C_k=\bigcup_{j=1}^{2^k}I_{k,j}$$  where $I_{k,j}$ are pairwise disjoint closed intervals of length $3^{-k}$ in $[0,1]$, let  $$[0,1]\setminus C_k=\bigcup_{j=1}^{2^k-1}J_{k,j}$$  where $J_{k,j}$ are pairwise disjoint open intervals and each $J_{k,j}$ are located between intervals $I_{k,j},I_{k,j+1}$  define  $$F_k:[0,1]\to[0,1]$$  where  $$F_k(0)=0,F_k(1)=1,F_k(x)=\frac{j}{2^k}\quad x\in J_{k,j}$$  and $F_k$ is linear on each subinterval of $C_k$. We can show that $F_k$ converges to the Cantor function $F:[0,1]\to[0,1]$. Moreover, it can be shown that  $$|F_k(x)-F_k(y)|\leq\frac{3^k}{2^k}|x-y|$$  How can we show that $F$ is Hölder continuous of order $\log_32$ ? I am trying to create a directory that will house all and only my PDFs compiled from LaTeX. I like keeping each project in a separate folder, all housed in a big folder called LaTeX. So I tried running:  rsync -avn *.pdf ~/LaTeX/ ~/Output/   which should find all the pdfs in ~/LaTeX/ and transfer them to the output folder. This doesn't work. It tells me it's found no matches for "*.pdf". If I leave out this filter, the command lists all the files in all the project folders under LaTeX. So it's a problem with the *.pdf filter. I tried replacing ~/ with the full path to my home directory, but that didn't have an effect.  I'm, using zsh. I tried doing the same thing in bash and even with the filter that listed every single file in every subdirectory... What's going on here?  Why isn't rsync understanding my pdf only filter?    OK. So update: No I'm trying  rsync -avn --include="*/" --include="*.pdf" LaTeX/ Output/   And this gives me the whole file list. I guess because everything matches the first pattern... Rendering of Favorite/Ignored Tags in Firefox I have spotted a bug in rendering of Favorite Tags and Ignored Tags section in Firefox. This rendering issue is present on both stackoverflow.com and meta.stackoverflow.com sites.  I'm using Firefox 17.0.1 on Windows 7 x64. In Google Chrome page is rendered correctly.  Screenshots:  Firefox (please note cropped right part of both Add buttons)    Chrome (buttons are rendered correctly) I often find myself wishing SO supported drag and drop. For example I drag a tag to my favs and it would add it, or when searching by tag I would like to drag the tag to the search box and get [asp.net] added in the search box.   Does it make sense to add this feature or is it just too much work for so little use? I'm automating a web application (the Mantis bug tracker) and I'm getting an interesting response header from it, called Refresh:  HTTP/1.x 200 OK ... Refresh: 0;url=my_view_page.php   It seems to be acting the same way that  does, and the meta refresh technique implies that it is an equivalent of a header in HTTP.  Problem is, I can't find any mention of the Refresh header in the  or any other definitive documentation on how it should be parsed and what the browser should do when it encounters it.  What's going on here? Prove the $n$th Fibonacci number is the integer closest to $\frac{1}{\sqrt{5}}\left( \frac{1 + \sqrt{5}}{2} \right)^n$ Prove that the $n$th Fibonacci number $f_n$ is the integer that is closest to the number $$\frac{1}{\sqrt{5}}\left( \frac{1 + \sqrt{5}}{2} \right)^n.$$   Hi everyone, I don't really understand the problem. I have the following hint, but I don't know how to work it.     Hint: Show that the absolute value of $\frac{1}{\sqrt{5}}\left( \frac{1 - \sqrt{5}}{2} \right)^n$ is less than $1/2$. Can the Hubble constant be measured locally? Increase the visibility of the association bonus by documenting it with the other privileges View approximate number of users online Is there any way to view the number of users online at any given time (or even an approximation)?  This could be really useful to provide an indication of whether your question is likely to get answered any time soon.  It could also provide a bit of an indication for why your question is getting very low views - if there are only a few users online, then that could be the reason for little interest in a question, whereas if there are lots of users online and the question still doesn't garner many views, then maybe it needs to be rephrased or something.  I know that this can't be used definitively, but it could be used as a rough guide, and could also just be an item of interest.  Perhaps it could show the number of users that have been seen in the past 5 / 10 minutes? (Shouldn't be too hard, since each user page already shows the last time that they were seen). Why don't we define division by zero as an arbritrary constant such as $j$? Why don't we define $\frac 10$ as $j$ , $\frac 20$ as $2j$ , and so on? I know that by following the rules of math this eventually leads to $1=2$ , but we could make an exception and say that $j$ is the only number such that $0*j \not= 0$ , and put other restrictions necesary so that we don't get contradictions. We do this for $i$ , so why can't we do it here? For example, $i^2$ , is defined as $-1$ , but you could also say $i^2=\sqrt {-1} *\sqrt {-1}=\sqrt {(-1)(-1)}=\sqrt{1}=1$ , but we make an exception for this. Normalizing the final weights vector in the upper bound on the Perceptron's convergence The convergence of the "simple"  says that:  $$k\leqslant \left ( \frac{R\left \| \bar{\theta} \right \|}{\gamma } \right )^{2}$$  where $k$ is the number of iterations (in which the weights are updated), $R$ is the maximum distance of a sample from the origin, $\bar{\theta}$ is the final weights vector, and  $\gamma$ is the smallest distance from $\bar{\theta}$ to a sample (= the margin of hyperplane).  Many books implicitly say that  $\left \| \bar{\theta} \right \|$ is equal to 1. But why do they normalize it ? Most RPGs teach you that casual violence is the best solution to all your in-game problems. This is so well established a part of the vast majority of RPGs that there are entire satire RPGs like Greg Costikyan's  and John Tynes'  dedicated to showcasing the issue. Even now that the '80's anti-RPG hysteria is past, you see more sober critiques of endemic violence in RPGs in places like . In most RPGs, PCs become inured to murder and other antisocial activities very quickly, and enter the depths of depravity that wouldn't be appropriate in the worst parts of the world. Armed robbery, mass murder, and genocide become routine parts of an adventurer's day, something only stick-in-the-mud characters with the most extremely stated ethics object to. , even though it is not properly applied to just any conflict, is a PC's friend and they generally escalate any conflict in that direction. The sophistication of the gamer mindset towards introspection on this issue can be demonstrated in that the most meaningful question usually debated about in-game violence is some variant on &quot;but should we kill the noncombatant children&quot; or &quot;can we just murder people out of hand as long as they're from a typically evil race?&quot; In the real world, we generally a priori regard anyone having to have this discussion as a monster already. (P.S. The &quot;wipe out a given evil race&quot; thing isn't the point of this question; it is only mentioned to indicate that it's only &quot;that far&quot; that usually causes ethical handwringing from players, when that is a really quite extreme case and we should be uncomfortable with casual violence a lot sooner. ) What I'd like to have is a more realistic in-game treatment of conflict.  People getting wounded and giving up, taking and ransoming of prisoners, not always escalating a fistfight to weapons, not always escalating weapon combat to killing, etc.  Heck, as I write this, I'm watching an episode of Adventure Time with my daughter and the protagonists snuck in and rescued a princess kidnapped by the Ice King and then exit right next to his sleeping form. I thought, &quot;If this were D&amp;D they'd all be carefully coordinating a coup de grace to kill him in his sleep on the grounds that he inconvenienced them.&quot;  The problem isn't limited to D&amp;D of course, sci-fi PCs are happy to neutron bomb planets for convenience too, for example. I'm not part of the &quot;D&amp;D is Satanic&quot; crowd obviously, but I frankly do have compunctions about continually playing in games where the taught behavior is uncomfortably equivalent to the worst examples of human behavior we see on the nightly news. How can I give my PCs a newfound respect for human life? Get attention to a new answer to an old question It happened to me that I found a solution to an older question. This question was commented by many people with comments like "very interesting, important, ..." such that I thought that my answer has also some value. My answer was the only one. It was upvoted and accepted by the asker. However, I assume, that very few of the "commentators" saw my answer, because the system does not inform automatically about new answers.   I think it would have been helpful for me and the commentators when they would get informed. I could achieve this by adding my own comment to their comments, because this triggers a system message. My question is: would this action be considered admissible or not? Are there some other possibilities? Someone gave me a bunch of envelopes of pizza crust yeast, "specially formulated for pizza crust". The packets also say that no rise time or proofing is needed, and that it's "NOT recommended for bread baking." The ingredients are yeast, enzymes, sorbitan monostearate, l-cysteine, and ascorbic acid. It does provide a recipe for pizza crust, with just mixing and a bit of kneading.   What has actually been done to this yeast to make it work like this? (What are those enzymes?) And is there any way I can use it for other things, or is it really only good for things like pizza crust? Validity of naively computing the de Broglie wavelength of a macroscopic object Many introductory quantum mechanics textbooks include simple exercises on computing the de Broglie wavelength of macroscopic objects, often contrasting the results with that of a proton, etc.  For instance, this example, taken from a textbook:     Calculate the de Broglie wavelength for      (a) a proton of kinetic energy 70 MeV      (b) a 100 g bullet moving at 900 m/s   The pedagogical motivation behind these questions is obvious: when the de Broglie wavelength is small compared to the size of an object, the wave behaviour of the object is undetectable.  But what is the validity of the actual approach of applying the formula naively? Of course, a 100g bullet is not a fundamental object of 100g but a lattice of some $10^{23}$ atoms bound by the electromagnetic force. But is the naive answer close to the actual one (i.e. within an order of magnitude or two)? How does one even calculate the de Broglie wavelength for a many body system accurately? Opening Chromium on Ubuntu VPS Ubuntu noob here. I recently got a VPS running Ubuntu, and decided to install Chromium, my preferred browser, on it. After installation completed, I got a message stating that I cannot open Chromium with root privileges. How would I go about opening Chromium? Is there a way to indicate to  how/where to find (paths to)  tools such as python, nmap, php and so on?  I ask this because when I schedule a job using crontab -e, I always need to specify the full path of python, nmap and whatever other tool I want to use. How can I turn on the Intel HD manually? For some weeks my MacBook 6.2 does not switch to the integrated graphics adapter (Intel HD). This is especially crucial when I work on battery (which happens quite often). I guess the runtime could be enhanced when it would take the HD adapter for display.  I checked that it automatically changes the graphics mode. I am running Snow Leopard 10.6.8.  I recently installed 8GiB RAM (not from Apple). Could this probably related to this issue? Actually I do not want to downgrade or use the expensive Apple RAM.  So, how can I manually turn on the internal graphics adapter? Impact of hyperref, when varioref and cleveref are used The axiom of choice asserts that for any set $X$ there exists a function $f : (2^X − \{\emptyset\}) \rightarrow X$ such that for any nonempty $A \subseteq X$, $f(A) \in A$. Show that this is equivalent to the assertion that every relation includes a function with the same domain. I am given this problem in my assignment. My approach is following. I have a set $X$. Then it has a choice function $g : \mathcal{P}(X) \setminus \left\{\emptyset\right\} \rightarrow X$. Suppose $X$ has a relation $R \subseteq X \times X$. $dom(R) \subseteq X$. Then the required function $f : dom(R) \rightarrow X$ is $$f(x) = g(\{y\ |\ (x, y) \in R\})$$ Conversely, suppose $X \supseteq Y$ is a non-empty subset. Let $$R_Y = \{(x, y)\ |\ y \in Y, x \in Y, (p, q) \in R_Y \Rightarrow p = x\}$$ Then there is a function $f_Y : dom(R_Y) \rightarrow X$. But $dom(R_Y)$ is singleton from the definition of $R_Y$. Then $im(f_Y)$ is also singleton. We define our choice function as $f = \{(Y, y)\ |\ y \in im(f_Y)\}$ Are my arguments correct?  Edit.1: what I tried to do for converse is, for any subset $Y$, I construct a relation $Y_1 \times Y$ where $Y \supseteq Y_1 = \{y\}$. Then there is a function $f_Y : Y_1 \rightarrow Y$. Then if $f$ is my choice function I define $f(Y) = f_Y(y)$. May be I should define $R_Y$ as $$R_Y = \{(x, y)\ |\ y \in Y; x \in Y; (p, q), (p', q) \in R_Y \Rightarrow p = p'\}$$ I understand there may be multiple $R_y$'s. But can't I define a singleton set as $\{s\in S\ |\ a, b \in S \Rightarrow a = b\}$? This can be $\{s\}$ $\forall s \in S$. But isn't it a valid specification?  Edit.2: This is the final solution with the help from @Asaf.  If we assume axiom of choice then for any $X$ there is a choice function $f : \mathcal{P}(X) \setminus \left\{\emptyset\right\} \rightarrow X$ such that $f(A) \in A$. Suppose $R$ is a relation between $P$ and $Q$. Then we have a choice function $f_Q$ for $Q$. Let $f_R(p) = f_Q(\{q\ |\ pRq\})$. The function $f_R : P \rightarrow Q$ and $dom(f_R) = dom(R)$. So this is our required function.  Conversely, if every relation includes a function with same domain. Let $R$ be a relation between $\mathcal{P}(X) \setminus \left\{\emptyset\right\}$ and $X$ such that $aRb \Rightarrow b \in a$. Now $R$ includes a function $f : \mathcal{P}(X) \setminus \left\{\emptyset\right\} \rightarrow X$. Then $xRf(x) \Rightarrow f(x) \in x$. So $f$ is the choice function for $X$.