I installed VLC player on my Ubuntu 14.04 system. DVD movies won't play (no sound or picture) even though the computer tries to start the movie. What's wrong? Is the version wrong for Ubuntu 14.04?
My machine can't play encrypted DVDs on a fresh install.  How do I add this capability?  Another useful bit of information would be what programs are best for playing DVDs, once I'm able to do so.  See the .  Will I be able to play DVD movies from ?
After looking into the different OAuth types and reading , I'm still confused on the specific pros and cons of user-agent vs web server flows.  The best explanation I can find says that user-agent tends to be used for mobile but it seems that they can both be used for desktop.   What makes it more appropriate to use one over the other in certain scenarios? Cooking away alcohol When you cook with wine or spirits, when does the alcohol cook away? Obviously high temperatures will do it, but how low of temperatures will work? Also, does it vary by the type of alcohol? pgrouting unexpected output Evaluate $\prod \frac {2k - 1} {2k}$ I came across to this: evaluate $$\prod_{k = 1}^{n} \frac {2k - 1} {2k}.$$  I brought it to a closed-form expression in asymptotics but I suspect my asymptotics is bad and I also want to see different solutions, hence the question.  My original solution: Write   $$\begin {eqnarray} \prod_{k = 1}^{n} \frac {2k - 1} {2k} &amp; = &amp; \exp \left (\sum_{k = 1}^{n} \log \left (1 - \frac {1} {2k}\right) \right) \nonumber \\ &amp; = &amp; \exp \left (- \sum_{k = 1}^{n} \sum_{m = 1}^{\infty} \frac {1} {(2k)^m m}\right). \end {eqnarray}$$  Let $$S = \sum_{m = 1}^{\infty} \frac {1} {(2k)^m m} \tag {1}.$$ Multiply both sides of $(1)$ by $2k$ to get $2k S &lt; S + 1$, and by $4k$ to get $4kS &gt; S + 2$. Hence, $$\frac {2} {4k - 1} &lt; S &lt; \frac {1} {2k - 1}.$$ Then, $$\frac {1} {2} \left( \log (4n - 1) - \log 3 \right) - 2 + O \left(\frac {1} {n^2}\right) &lt; \sum_{k = 1}^{n} \sum_{m = 1}^{\infty} \frac {1} {(2k)^m m} &lt; \frac {1} {2} \log (2n - 1) - 1 + O \left(\frac {1} {n^2}\right).$$ Hence, $$\sqrt {\frac {c} {2n - 1}} &lt; \prod_{k = 1}^{n} \frac {2k - 1} {2k} &lt; \sqrt {\frac {3 c^2} {4n - 1}},$$ where $c$ is a constant. Any better approach? why does fdisk add one additional sector when creating partitions? I'm playing around with fdisk and I tried to create a partition on an empty USB drive. Here's how that went: Command (m for help): n Partition number (1-128, default 1): 1 First sector (34-61187102, default 2048): 2048 Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-61187102, default 61187102): +30000000           Created a new partition 1 of type 'Linux filesystem' and of size 14,3 GiB.  so just one partition with 30 million sectors. However, when I check how many sectors it contains I get:  I'm checking with a different program and I see again that additional sector:  Sorry for the pettiness :) I'm learning. Check if all elements in a list are identical What is the status of existing measurements of the speed of gravity? theorem numbering: section counter but remove the section number Any way to open windows from the windows bar using a shortcut? for example to open the first window on the left Ctrl+1, to open the second window on the left Ctrl+2.  Im using xfce4 at this moment, but if under xfce4 is not possible, is there any other desktop environment that permits this?  Since I have several windows open for the same application, I not searching for sortcuts related to the application but as I say below, to the window. Statistics module doesn't show the "Enable access log" checkbox I dont know what to do to show "Enable access log" option.  I activated logging all messages and checked all statistics permissions.  Thanks. Statistical inference when the sample "is" the population Imagine you have to do reporting on the numbers of candidates who yearly take a given test. It seems rather difficult to infer the observed % of success, for instance, on a wider population due to the specifity of the target population. So you may consider that these data represent the whole population.   Are results of tests indicating that the proportions of males and females are different really correct? Does a test comparing observed and theoretical proportions appear to be a correct one, since you consider a whole population (and not a sample)? What is a "DIE" package? In a list of ICs, along with the familiar package names such as QFN32, LQFP48, etc., I've seen a few ICs to be listed as DIE for the package size. I've never seen that description before as an IC package size, and  does not list it either.  What can it be?  I assume it's some kind of chip-scale package, but it does not reveal the silicon size or any other properties, like number of pins, etc. Meaning of the word "axiom" Thus, axioms are propositions we assume to be true and we use them in an axiomatic theory as premises to infer conclusions, which are called "theorems" of this theory.  For example, we can use the  to prove theorems of arithmetic.  This is one meaning of the word "axiom". But I recognized that the word "axiom" is also used in quite different contexts.  For example, a group is defined to be an algebraic structure consisting of a set $G$, an operation $G\times G\to G: (a, b)\mapsto ab$, an element $1\in G$ and a mapping $G\to G: a\mapsto a^{-1}$ such that the following conditions, the so-called group axioms, are satisfied:   $\forall a, b, c\in G.\ (ab)c=a(bc)$, $\forall a\in G.\ 1a=a=a1$ and $\forall a\in G.\ aa^{-1}=1=a^{-1}a$.      Why are these conditions (that an algebraic structure has to satisfy to be called a group) called axioms? What have these conditions to do with the word "axiom" in the sense specified above? I am really asking about this modern use of the word "axiom" in mathematical jargon. It would be very interesting to see how the modern use of the word "axiom" historically developed from the original meaning.   Now, let me give more details why it appears to me that the word is being used in two different meanings:  As peter.petrov did, one can argue that group theory is about the conclusions one can draw from the group axioms just as arithmetic is about the conclusions one can draw from the Peano axioms. But in my opinion there is a big difference: while arithmetic is really about natural numbers, the successor operation, addition, multiplication and the "less than" relation, group theory is not just about group elements, the group operation, the identity element and the inverse function. Group theory is rather about models of the group axioms. Thus: The axioms of group theory are not the group axioms, the axioms of group theory are the axioms of set theory.  Theorems of arithmetic can be formalized as sentences over the signature (a. k. a. language) $\{0, s, +, \cdot\}$, while theorems of group theory cannot always be formalized as sentences over the signature $\{\cdot, 1, ^{-1}\}$. Let me give an example: A typical theorem of arithmetic is the case $n=4$ of Fermat's last theorem. It can be formalized as follows over the signature $\{0, s, +, \cdot\}$: $$\neg\exists x\exists y\exists z(x\not = 0\land y\not = 0\land z\not = 0\quad\land\quad x\cdot x\cdot x\cdot x + y\cdot y\cdot y\cdot y = z\cdot z\cdot z\cdot z).$$ A typical theorem of group theory is  which states that for any finite group G, the order of every subgroup H of G divides the order of G. I think that one cannot formalize this theorem as a sentence over the "group theoretic" signature $\{\cdot, 1, ^{-1}\}$; or can one? Create Trigger that updates the same table before (or after ??) the Insert I have just started using triggers and one thing that I would need to do is to create a trigger that updates the same table that's inserting the row.  TABLE:  CREATE TABLE `city` (   `city_id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,   `city` varchar(50) NOT NULL,   `country_id` smallint(5) unsigned DEFAULT '0',   `country` varchar(150) DEFAULT NULL,   `last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,   PRIMARY KEY (`city_id`),   KEY `idx_fk_country_id` (`country_id`),   CONSTRAINT `city_ibfk_1` FOREIGN KEY (`country_id`) REFERENCES `country` (`country_id`) ON UPDATE CASCADE ) ENGINE=InnoDB AUTO_INCREMENT=6009 DEFAULT CHARSET=utf8;   Trigger:  DELIMITER $$ CREATE TRIGGER `populate_country_id` BEFORE INSERT ON `city` FOR EACH ROW BEGIN  IF NEW.country_id = 0  THEN     UPDATE city     INNER JOIN country B ON city.country = B.country     SET NEW.country_id = B.country_id;  END IF;  END $$ DELIMITER ;   MySQL is just returning: Can't update table 'city' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.  Is there any way I can make this work?  Thanks everyone! What permissions should my website files/folders have on a Linux webserver? This is a  about File Permissions on a Linux web server.   I have a Linux web server running Apache2 that hosts several websites. Each website has its own folder in /var/www/.  /var/www/contoso.com/ /var/www/contoso.net/ /var/www/fabrikam.com/   The base directory /var/www/ is owned by root:root. Apache is running as www-data:www-data. The Fabrikam website is maintained by two developers, Alice and Bob. Both Contoso websites are maintained by one developer, Eve. All websites allow users to upload images. If a website is compromised, the impact should be as limited as possible.  I want to know the best way to set up permissions so that Apache can serve the content, the website is secure from attacks, and the developers can still make changes. One of the websites is structured like this:  /var/www/fabrikam.com     /cache     /modules     /styles     /uploads     /index.php   How should the permissions be set on these directories and files? I read somewhere that you should never use 777 permissions on a website, but I don't understand what problems that could cause. During busy periods, the website automatically caches some pages and stores the results in the cache folder. All of the content submitted by website visitors is saved to the uploads folder. Why is the range of inverse trigonometric functions defined in this way? My question is really simple, why is the range of the $\sin^{-1}(x)$, $\cos^{-1}(x)$ and $\tan^{-1}(x)$ defined as $[-\pi/2,\pi/2]$, $[0,\pi]$ and $[-\pi/2,\pi/2]$ respectively? Is there some particular reason? We could choose another range for each inverse trigonometric function. For example, we can pick $[0,\pi]$ to be the range of $\sin^{-1}x$.  EDIT  I've understood why the range of the sine and cosine has to be $[-\pi/2,\pi/2]$ and $[0,\pi]$ respectively. I'm still wondering why can't we define the range of the tangent as $[0,\pi]$ How to activate quota for users on folders? Why did JJ Abrams recreate the Star Trek Timeline? In the 2009 version of Star Trek, Nero and the Romulans come back through time via Blackhole and kill Kirk's dad and the original Star Trek timeline is altered  creating a whole new reality.  Why would Abrams not just stick to the timeline given by Roddenberry instead of altering it? I've got a few macros that perform floating point lookups and calculations for me and I'm interesting in plotting their results. They're the kind of calculation which requires if/else, so they can't be easily written as a simple math formula for \addplot.  Thanks to a previous question (), I now know to use \pgfmathdeclarefunction, but after trying it I've found that addplot seems to prepend a "0Y" or "1Y" to values before passing them as function arguments. My external macros aren't prepared to handle this extra text, and I'm not sure why it's there.   In the course of testing things out, I've also found that calling a function defined with pgfmathdeclarefunction can also change the positioning of the graph...  \documentclass{article}  \usepackage{xparse}  \usepackage{pgfplots} \pgfplotsset{compat=1.10}  \begin{document}  % Example of a macro which does math outside of pgf     \ExplSyntaxOn     \DeclareExpandableDocumentCommand \doubleMacro { m }%      {%       \fp_eval:n { #1*2 }%Math performed by a package other than pgfplots      }%     \ExplSyntaxOff    %Demo: macro does work in regular text \doubleMacro{1.1}.  % Defining custom pgf functions for plotting      \pgfmathdeclarefunction{mathDoubleMacro}{1}{%         \pgfmathparse{\doubleMacro{#1}} %Calls macro which performs math done by another package     }      \pgfmathdeclarefunction{mathDoublePgf}{1}{%         \pgfmathparse{#1*2} %Uses pgf to do the same thing as an external macro could     }  %Generic plot with function given directly to \addplot \begin{center} \begin{tikzpicture}     \begin{axis}         \addplot[domain=0:1] {2*x};     \end{axis} \end{tikzpicture} \end{center}  %Plot using first macro: complains about 'Unknown fp word Y.' \begin{center} \begin{tikzpicture}     \begin{axis}         %\addplot[domain=0:1] {mathDoubleMacro(x)};%Commented out because it gives problems     \end{axis} \end{tikzpicture} \end{center}  %Plot using second macro: works, but graph is displaced to the right of the expected position \begin{center} \begin{tikzpicture}     \begin{axis}         \addplot[domain=0:1] {mathDoublePgf(x)};     \end{axis} \end{tikzpicture} \end{center}  \end{document}   If I define mathDoubleMacro as calling a non-existent macro, then the errors show which x-values which the addplot is trying to evaluate y at:    0Y0.0e0  1Y4.1666e-2 1Y8.3332e-2 ...  1Y9.9998401e-1   What are these nY's all about, and why does \addplot[domain=0:1] {mathDoublePgf(x)} give a graph with different positioning? Some months ago I posted  about exporting Sentinel 1 scenes from a collection and was successful with help from .   I now have a new region of interest, which sits on the overlap between 2 scene footprints (sequential images in descending orbit). When I make a mosaic of the 2 scenes I get a small no data gap and lack of alignment between the 2 images:  // Create a geometry representing an export region. var roi = ee.Geometry.Rectangle([-62.67, -8.31, -63.25, -8.85]); var zoomPoint = ee.Geometry.Point([-62.35, -8.06])  // Load the Sentinel-1 ImageCollection. var sentinel1 = ee.ImageCollection('COPERNICUS/S1_GRD') .filterBounds(roi);   // Filter by metadata properties. var IW_H = sentinel1  // Filter to get images with VV and VH dual polarization. .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'VV')) .filter(ee.Filter.listContains('transmitterReceiverPolarisation', 'VH'))  // Filter to get images collected in interferometric wide swath mode. .filter(ee.Filter.eq('instrumentMode', 'IW'))  // Filter IWs to get High res. .filter(ee.Filter.eq('resolution', 'H'))  // Filter IW-Highs to get 10m res .filter(ee.Filter.eq('resolution_meters', 10));  // Filter to get images from different look angles var col_desc = IW_H.filter(ee.Filter.eq('orbitProperties_pass', 'DESCENDING'));  // Spatially mosaic the images in the collection and display var col = col_desc.mosaic(); var colVV = col.select(0) Map.addLayer(colVV, {min:-17, max:-3}, "VV"); Map.centerObject(zoomPoint, 20);   What am I missing?  Are these scenes not acquired sequentially?