How to use a Butterworth bandpass filter to generate a chirped signal
How to generate a chirped signal
If we pick randomly two points inside a circle centred at $O$ with radius $R$, and draw two circles centred at the two points with radius equal to the distance between them, what is the expected area of the intersection of the two cirlces that contain the origin $O$. When using vagrant Stderr: VBoxManage: error: VT-x is not available (VERR_VMX_NO_VMX) I am trying to install open edx with  ubunty 16.04 and I get this error  There was an error while executing `VBoxManage`, a CLI used by Vagrant for controlling VirtualBox. The command and stderr is shown below.  Command: ["startvm", "c60f0594-d584-4e0b-b863-2801168e641e", "--type", "headless"]  Stderr: VBoxManage: error: VT-x is not available (VERR_VMX_NO_VMX) VBoxManage: error: Details: code NS_ERROR_FAILURE (0x80004005), component ConsoleWrap, interface IConsole   this occurs when using vagrant up Currentsection TOC in scrartcl? I like to get a toc at beginning of some of my sections, like in beamer where I can use \tableofcontents[currentsection] is there a possibility in scrartcl?  Something like this:  \documentclass[10pt,a4paper]{scrartcl} \usepackage[ngerman]{babel}  \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc}  \begin{document}  \tableofcontents %complete  \section{First}  \section{Second} \tableofcontents %just subsection and subsubsection \subsection{SecondSub} \subsubsection{please} \subsection{this} \subsection{SecondSub2} \subsection{parts}  \section{Third} \subsection{another}  \end{document}   Looks like:  Inhaltsverzeichnis %complete  1 First  2 Second 2.1 SecondSub.......................2 2.1.1 please........................2 2.1.2 this..........................2 2.2. SecondSub2.....................3 2.2.1 parts.........................4  3 Third 3.1 another ........................5   1 First  2 Second  Inhaltsverzeichnis %just subsection and subsubsection 2.1 SecondSub.......................2  2.1.1 please........................2  2.1.2 this..........................2 2.2. SecondSub2.....................3  2.2.1 parts.........................4  2.1 SecondSub  2.1.1 please   2.1.2 this  2.2. SecondSub2  2.2.1 parts   3 Third  3.1 another Ubuntu App Development. Unable to install Ubuntu SDK and buggy Ubuntu emulator Something wrong with monthly user rep - some users show quarterly figures? I am used to Turbo C++ and I am new to Ubuntu.  I really need Turbo C++ to get started.  Can somebody please help me to install Turbo C++ on Ubuntu. From my , I learned that all tag related info on profile will be updated daily at UTC 03:00.  However, something is wrong here. It's now UTC 05:00+, but my tag number, say 93 (c++) is not updated against yesterday. I am pretty sure about this and I did earn some more points throughout the day. Sorry for not be able to capture the screenshot yesterday, but I did check this number 10 hours ago (which belongs to yesterday, also 93).  Is there a bug happening here? Or updating time different?    UPDATE: As of 24 Jan, the tags are still not updated with the proper values.  UPDATE2: Fixed around 25 Jan, UTC 03:00, at least for me. MySQL Date Between Centering figure captions in IEEEtran I am working on a paper using the IEEEtran template in LyX.  I have run into a problem: While the contents (in this case, a table) of the figure float are centered, the caption is aligned to the left (see screenshot below). How can I center the caption as well?    This is generated by the following LyX document:    What I've tried:   Center the table (the table is centered) Center all the contents in the float (only the table is centered) Select the caption and center it (no effect)   Technical details:   LyX 2.0.5.1 Mac OS X 10.7.5 (Lion) All centering was performed by Right Click>Paragraph Settings>Align: Center Root filling up although it should have some space This has been perplexing me for some time. I'm on Ubuntu 11.04. My root partition is filling up and I can't figure out what's causing it. Even stranger, when I run df -h, this is the output:  Filesystem            Size  Used Avail Use% Mounted on /dev/sda2             9.2G  8.8G     0 100% /   As you see, there should be about 400 MB free, but Avail shows 0. What could be causing this? I've even uninstalled some programs to free the space and it fills up again. Suggestions on how to find out which, if any, files are filling up the space are also welcome. I installed Drush for the first time (so it may be a configuration error) and I'm trying to update to the latest core version of Drupal.  Drush is giving me this error - I'm on an OSX box.  dev5:clientnamedirectory my.name$ drush pm-update projects drupal-7.25 &lt;h1&gt;Additional uncaught exception thrown while handling exception.&lt;/h1&gt;  &lt;h2&gt;Original&lt;/h2&gt;&lt;p&gt;PDOException: SQLSTATE[HY000] [2002] No such file or directory in drupal_get_installed_schema_version() (line 155 of /Users/my.name/Sites/proface/includes/install.inc).&lt;/p&gt;  &lt;h2&gt;Additional&lt;/h2&gt;  &lt;p&gt;PDOException: SQLSTATE[HY000] [2002] No such file or directory in system_list() (line 165 of /Users/my.name/Sites/clientnamedirectory/includes/module.inc).&lt;/p&gt;&lt;hr /&gt;  Drush command terminated abnormally due to an unrecoverable error. If matrix A is invertible, is it diagonalizable as well? If a matrix A is invertible, then it is diagonalizable. Is it true or false? How can I debug my JavaScript code? Is there a way to access wifi in Zurich airport without a phone service? I am traveling through Zurich and have a phone without any roaming there; I'm planning on picking up a SIM once I get to my final destination. Last time I was there, I couldn't access the airport wifi because it required a code sent via SMS.    In the event I need to contact someone or coordinate about flight delays, is there some alternate way to get wifi access? Possible Duplicate:             Well, I remembered this after having Algebra II a year ago, is it possible that this is a valid proof that $1 = -1$?  $$ 1 = \sqrt{1} = \sqrt{-1\cdot-1} = \sqrt{-1} \cdot \sqrt{-1} = i \cdot i = i^2 = -1 $$  $$ \therefore 1 = -1 $$  So is this actually fully valid? Or can it be disproved? Add a "flag" button in the revision list Note: this is intended to be a canonical question about summoning sickness.  "Summoning sickness", broadly, is the rule that stops you from attacking or paying {T} costs with a creature that you just played. But how exactly does it work? How does it interact with other rules and effects?  For example, if I'm trying to figure out how a creature is affected:   Does the status matter (tapped/untapped, face down/face up, etc.)? What if it came into play, but I didn't cast it? What if it's a token? What if it was on the battlefield when my turn started, but it wasn't a creature? What if it stops being a creature? What if it's a creature and also another card type? What if it's a double-faced card that just transformed? What if it changes control? What if it's a copy of another creature? Which of the creature's activated abilities can I use? Are any of its other abilities affected? Can I tap the creature to pay a cost that is not a {T} cost?   (These examples are primarily taken from questions about summoning sickness that have already been asked on the site) On Takodana,      the main characters and various bar patrons can see the planet Hosnian Prime being destroyed by Starkiller Base with their (respective) naked eyes. How did they see this? Is the Hosnian system close enough to see? If it's not very close and they could just see the explosion, how did the light from it reach them so quickly? every planar graph can be expressed as a union of five edge-disjoint forests How can I prove that every planar graph can be expressed as a union of (maximum) five edge-disjoint forests?  Only thing I can think about is going somehow like the $5$ color theorem but I get stuck in the middle. Or with induction, but still something doesn't fit. Can you help? How to make a cylinder / pipe with slanted ends (like pasta penne)?