I've been trying to make an addon in Blender 3D, and have basically started out making a custom button that's going to generate a mesh. I want a custom icon for the mesh I'm going to generate, and I can get it to work as a script, but not as an addon. So when I click 'run script' a button shows up with my icon (which is in a folder called 'icons')  I've seen one code template that looks promising for an addon, but I can't get my icon to load when I try it:  If anyone has any examples of working addon code (like an example addon with a custom button with a custom icon) it would be very helpful.  I've already tried using one solution I found on this site, but it only works as a script, and not as an addon. Here's the code that works as a script:     #---------------------------------------------------------- # File hello.py #---------------------------------------------------------- import bpy  # #    Menu in tools region # class ToolsPanel(bpy.types.Panel):     bl_label = "MyAddon"     bl_space_type = "VIEW_3D"     bl_region_type = "TOOLS"       def draw(self, context):         self.layout.operator("hello.hello", icon_value=custom_icons["custom_icon"].icon_id)         global custom_icons  #  class OBJECT_OT_HelloButton(bpy.types.Operator):     bl_idname = "hello.hello"     bl_label = "Generate MyMesh"     bl_icon= "custom_icons[custom_icon].icon_id"     country = bpy.props.StringProperty()      def execute(self, context):         if self.country == '':             print("Hello world!")         else:             print("Hello world from %s!" % self.country)         return{'FINISHED'}      # #    Registration #   All panels and operators must be registered with Blender; otherwise #   they do not show up. The simplest way to register everything in the #   file is with a call to bpy.utils.register_module(__name__). #  bpy.utils.register_module(__name__)  import os import bpy import bpy.utils.previews  class Panel(bpy.types.Panel):     """Creates a Panel in the 3D view Tools panel"""     bl_label = "Custom Icon Preview Panel"     bl_space_type = "VIEW_3D"     bl_region_type = "TOOLS"      def draw(self, context):         global custom_icons   # global variable to store icons in custom_icons = None  def register():     global custom_icons     custom_icons = bpy.utils.previews.new()     script_path = bpy.context.space_data.text.filepath     icons_dir = os.path.join(os.path.dirname(script_path), "icons")     custom_icons.load("custom_icon", os.path.join(icons_dir, "icon.png"), 'IMAGE')     bpy.utils.register_module(__name__)  def unregister():     global custom_icons     bpy.utils.previews.remove(custom_icons)     bpy.utils.unregister_module(__name__)  if __name__ == "__main__":     register()

Is it possible to use different icons other than the default set and how?


I am working in R and would like to generate 40 numbers from $\mathrm{N}(0,1)$ and another 40 from $\mathrm{Uniform}(0,2)$ with a negative correlation (for example: $r = -0.45$) between them. The correlation does not have to be exact.   I've done something similar for 2 normally distributed variables by specifying a co-variance matrix - see R code below:  sigma <- matrix(c(.33,-.23,-.23,1), ncol=2, byrow=T)  mu <- c(1,0)  ab <- mvrnorm(n=40, mu, sigma)   One thing I considered was using the above code and then transforming one of the normal variables to a uniform but I am not sure how to go about doing that.

For a simulation study I have to generate random variables that show a predefined (population) correlation to an existing variable $Y$.  I looked into the R packages copula and CDVine which can produce random multivariate distributions with a given dependency structure. It is, however, not possible to fix one of the resulting variables to an existing variable.  Any ideas and links to existing functions are appreciated!     Conclusion: Two valid answers came up, with different solutions:   An R  by caracal, which calculates a random variable with an exact (sample) correlation to a predefined variable An R  I found myself, which calculates a random variable with a defined population correlation to a predefined variable     [@ttnphns' addition: I took the liberty to expand the question title from single fixed variable case to arbitrary number of fixed variables; i.e. how to generate a variable having predefined corretation(s) with some fixed, existing variable(s)]


EDIT: Just wondering why was this question closed as a duplicate of a question asked almost 2 years after this one... I've seen an example of how to sign using RSA. Besides the signing itself (s = m^d mod n) it also hashes and adds an IV. Why is that needed?

The  below illustrates the process of  a message with RSA:    As diagram shows, the message is first hashed, and the signature is then computed on the hash, rather than on the full message.  Why hash the data before signing it? Why not sign the whole message? Of course, it'll save time if you sign just the hash value, but I've heard there are also security issues with directly signing the full message. If so, what are they?


I need to edit a photo on my Mac. I wish to take two photos and paste them together to create one that's larger, containing both. I couldn't figure out how to do this with iPhoto.   For Windows you have Paint.NET.    For Linux you have Kolourpaint.   What would be the equivalent on OS X?  Please note that it must be of quality both in code and in UI. I wouldn't want to install buggyware on my Mac.

I tried out several image editors mentioned on  but some of them (like  and ) were very disappointing. These apps were too simple and low level.  What do you suggest for a (preferably free) image editor on OS X?  P.S: I was using  on Linux and also know that it was released for OS X too, but I want to find new good applications.


When saving artwork made in Illustrator for web, what should the dpi be when saving it as a JPG or PNG?   For example, say I save my artwork at 500px wide, is it better to save it at 72 dpi or 300 dpi? What do people typically do? Thanks.

I've been seeing the word 'DPI' pop up quite a lot when I export my work out in Photoshop and Illustrator. While I know that DPI stands for 'dots per inch', and that if you have too low of a DPI on an image, heavy pixellation occurs if you try to zoom in, what would be the optimal DPI for what situations?  For example (Situations):   Exporting a print A4 design Website layout Logo (Website only - Roughly smaller than the current SE Graphic Design one.) Logo (Scaling up and down - From business cards to large banners.)


Background: My Mac is out of commission, I don't want to borrow my son's Windows 8 laptop, and I don't want to install iTunes (or anything else that touches the Registry) on my employer's Window 7.  I have an MP3 file that I edited with "portable audacity" and I want to use "Music" with it.  I know there are other programs that can play it, but I have my reasons...  I've heard there are other programs that can get MP3s into the Music library.  Are any of them Windows-portable, i.e., can run from a flash drive without adding more garbage into the already full garbage can called "Registry"?  Or is there a portable file manager (for Windows) that can replace an MP3 file in the Music library with another of the same name (without jailbreaking to tamper with permissions)?  (In other words, something that would do what iTunes can do but won't touch the Windows registry.)  bmike, the answer is "if you think it's clearer, go for it."  SE is not cooperating with letting me log in and comment at the moment.  And I'll have my Mac again soon, at which point the question is only of value to someone besides me.  :-)

I can't find any definitive info on this and I need to know for sure before I purchase one.  I hate iTunes with a burning passion, but I like iPods and I have a whole lot of music on my PC.  How can I move music from a Windows computer to iOS without using iTunes?


In , they answer accepted by the asker, as been commented by multiple people, as not being neither standard, nor the recommended method.   What should be done in order to correct that ? (The asker seem to have been inactive for nearly the last 10 years)  Obviously, this is not a duplicate of «». I don't care about the why. What I'm looking for is a way to solve the problem.  Here we have a situation where  : 1/ It has been documented by multiple users, why the answer should not be the accepted one. It works, but the standards do not accept it as the recommended way of doing. And 2/ Since it is tagged as being the accepted answer, it receives supplementary likes from people which are glad with the first solution they find and won't even check comments or other answers  It is quite obvious than normal users won't be able to do it and that it requires help from someone with administrative rights. My question is about how we do that.

Here's the scenario:  Bob asks a question on Stack Overflow. Bob gets a few answers and selects the one that helps him the most. Bob's account gets deleted. Another (considerably better) answer is posted to Bob's question. The new answer soon scores higher than the accepted answer.  There is no way for Bob (or anyone) to change the accepted answer on the question. However, it's still the first thing everybody sees when they visit the question (despite the fact that there is a better answer further down). Now I can almost hear somebody asking the question, "but how often does this really happen?" I'm glad you asked. I just spent the last hour or so constructing a Data.SE query to answer exactly that:    The results? 3,177 rows. Naturally, I am wondering if there is anything that can be done about this. The following options immediately come to my mind:  Change the accepted answer. This option is here for completeness. I doubt anyone here (including me) actually would consider it. The accepted answer was selected by the user and changing it does not make sense.  Change the sorting order. This makes much more sense. Note that I am not advocating that we always change the sorting order whenever an answer outscores the accepted answer. I am only advocating that this happen when the OP's account has been deleted.  Remove the checkmark from the accepted answer. This option was suggested by Robert Harvey and I actually think it's a viable option as well. After all, the OP is no longer around, so I don't see much value in indicating which answer helped him the most.   Any thoughts? (Also, I'm not an SQL expert, so if you have suggestions for improving the query, feel free to point them out.)


I used feeds to import a csv file into a customized content types that have 12 fields. I managed to create a view and display as table.  Right now I'm trying to write some php code to output xml based on the parameters users passed in url, and I'm having a little trouble on building up the query on selecting all 12 field_data tables.  Any suggestions? Thanks

I need to find out the SQL query that is executed by a certain query. Views module can show the SQL when configuring the view but apparently . I am aware that the Devel module can show the database queries, but .  How can I find out the actual query that the view executes? The view is displayed as a block.


I have a small problem with Jquery click. On page load we display some things from a database. The startup code I mean is placed in the same file where the html is (This will be removed when the user searches for the first time because the div where are the list-item are in wil be cleared after searching to make place for the search results).  When you click on one of the items you get a popup menu with some info.  Now the problem: On the page we also have a search bar that searches things in a database. When you press search you get a list of search result. It is the same html code as on the page load but this time Jquery don't detect a click.  html:  <div class="list-item" data-singer= <?php echo '"'.$name.'"' ?> >

<?php echo $name ?>

<?php echo $tag ?>

             other info

   Jquery:  $('.list-item').click(function(){   alert();   name = $(this).data('singer');   name_modified = name.replace(" ", "_");   $(name_modified).ready(function(){     $('.popup > .content').empty();     $('.popup > .content').load('singers/' + name_modified + '.xml');     $('.popup').slideDown(500);   }); });   There is also another problem with the js code but I am already happy when I fix this problem. When you need more information leave a comment and I will add it.  And a message to downvoters. Leave a comment please.

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.


Please give me some hints or solution for this limit. I had it on my exam and I'm curious how to solve it. $$ \lim_{x\to 0} \frac{(x+1)^\frac{1}{x}-e}{x} $$


I can not see the right-most vertical bar given the following code:  \documentclass{beamer} \usepackage{pgfplots} \usepackage{tikz} \usetikzlibrary{arrows,positioning}   \begin{document} \begin{frame} \begin{tikzpicture} \begin{axis}[ybar interval,ytick style={draw=none},title={Redisuals Magnitude},       xlabel={Iteration (k)},       ylabel={$\|\rho_{k}\|_{\infty}$},       yticklabels={,,},xticklabels={,,},ylabel style={rotate=-90},xmin=0, xmax=8] \addplot coordinates { (0, 10) (1, 5) (2, 2.5) (3, 1.25) (4, 0.625) (5, 0.3125) (6, 3)}; \end{axis} \end{tikzpicture} \end{frame} \end{document}   How is it possible? How can I fix it?

I am using PGFplot to make a barchart. There are 4 entries in my csv file and unfortunately I have only 3 bars in my figure.   my LaTeX code:  \begin{figure}     \centering     \begin{tikzpicture}          \begin{axis}[             x tick label style={/pgf/number format/1000 sep=},                 xlabel=Sequence,             ylabel=Heigth,                 ymin=0.7,             enlargelimits=0.05,             legend style={at={(0.5,-0.15)},                 anchor=north,legend columns=-1},             ybar interval=0.7,             width=\textwidth,             ]             \addplot table [col sep=comma,trim cells=true,y=height] {numericaltests/data/test.csv};              \addplot[red,sharp plot,update limits=false]                 coordinates {(-1,1.00) (34,1.00)}                 node[above] at (axis cs:15,1.00) {};             \legend{Ca2Fe2As2}         \end{axis}     \end{tikzpicture}     \caption{Sequence}     \label{fig:sequenceHeight} \end{figure}   my test.csv file:  sequence,height 1,2.0 2,1.5 3,1.8 4,2.4   Barchart:


In Windows permanently deleting a file or folder without sending it to the recycle bin, is achieved by selecting that file or folder in Desktop or Windows explorer and then depressing the keyboard shortcut:  Shift + Delete  This is particularly useful for sensitive information.  Is there a keyboard shortcut equivalent within OS X that deletes files or folders permanently before they are disposed of in the trash.

I would like to delete and permanently delete a file in finder using del and shift+delete (windows style).  Is there any way to remap this in OS X lion?


I have recently updated both windows 10 and Ubuntu to the latest versions and apparently I can't access Windows anymore. I think it's caused by Grub since it says "alloc magic doesn't work". I've tried   sudo update-grub  but it won't work. I've also checked if the Windows partition still exists and it does.  To fix grub, some forums suggest to use the boot-repair program from yannubuntu, but typing   sudo add-apt-repository ppa:yannubuntu/boot-repair  only gives the result below:  E: The repository " bionic Release" doesn't have a Release file.  Can someone please tell me how to fix this?

When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?


I'm solving a problem you can see above: $PQRS$ is a trapezoid, $HM$ and $KN$ are legs bisectors. I'm supposed to prove that $\alpha = \beta$, which as you look closely can be reduced to proving $$\measuredangle SPM = \measuredangle NQR$$ (equivalently $\measuredangle PSM = \measuredangle NRQ$).  Hypothesis  These angles somehow resemble inscribed angles on arc $NM$. A circle could be circumsribed around $PQMN$ or $NMRS$. But I'm struggling with proving that one can actually circumsribe a circle around either of these. I'd appreciate some help from you.   you can find a brilliant drawing by User Raffaele who's done a great deal of work on the problem. However, a rigorous solution has not been provided by anyone.

Let $PQRS$ be a trapezoid. The bisectors of legs $PS$ and $QR$ intersect the opposite legs at $M$ and $N$ so that triangles $PMS$ and $QNR$ are formed.  Prove that $\measuredangle PMS= \measuredangle QNR$.  The question may seem easy but I fail to move on, playing with angles didn't help. I'd appreciate some hint from somebody with an eye for geometry and triangles.


Could someone give an example of a ‘very’ discontinuous derivative? I myself can only come up with examples where the derivative is discontinuous at only one point. I am assuming the function is real-valued and defined on a bounded interval.

There is a well-known result in elementary analysis due to Darboux which says if $f$ is a differentiable function then $f'$ satisfies the intermediate value property.  To my knowledge, not many "highly" discontinuous Darboux functions are known--the only one I am aware of being the Conway base 13 function--and few (none?) of these are derivatives of differentiable functions.  In fact they generally cannot be since an application of Baire's theorem gives that the set of continuity points of the derivative is dense $G_\delta$.  Is it known how sharp that last result is?  Are there known Darboux functions which are derivatives and are discontinuous on "large" sets in some appropriate sense?


I'm using Kubuntu 16.10 and I'd like to install tor browser bundle. I saw that there is a tor hardened version and sandboxed version. I downloaded packages but just extracting them doesn't work for me. So I need now to know how can i install both of them using terminal.

In Ubuntu 13.04 I used to use the ppa:upubuntu-com/tor64  PPA to install the 64-bit Tor Browser Bundle. However, in Ubuntu 13.10 it doesn't work anymore. How do I install the Tor Browser Bundle in Ubuntu?


There is a strange display issue with the comment flag popup.  When I open a comment from the Data Explorer, the comment appeared in the top of the page. Then I click the flag link, the popup box is appeared but overlapped with the Answer box.  This strange issue occurs when the comment's answer have the negative points and the answers are ordered by votes.    But I can manually click the partial visible part of the popup to flag the comment. Initially I found the issue in Stack Overflow and posted in its . Later I see the same issue in other SE communities too, so I posted here.  The following sample comments with negative votes, can be produce the issue:            The same is in the below GIF format:    It happened in the Google Chrome, Mozilla Firefox and Internet Explorer browsers.

The flag window on (a comment to) the last question is hidden beneath the answer box, as shown in the following screenshot:    Linked: , which is currently  - this is not fixed for flags on comments!


Is there any way by command-line (no softwares) to set a keyboard shortcut to toggle between 2 commands using the same shortcut key combination. Actually, i wanted to toggle my mousepad when using mouse.

I have a new dell laptop and I want to create a keyboard shortcut to disable and enable the touchpad. How do I do this?


I have a new Trek 720 Touring bike with about 1000 miles and have broken two spokes on the rear tire in the past two weeks and haven't yet added the weight of panniers.  This is a 24 spoke wheel and I'm told Trek doesn't have a 32 spoke wheel for this application.  I'm concerned for when I begin my cross-country touring in another month and adding another 30-35 # over that wheel.  This Trek model is new this year...anyone else out there have similar problems? I've traveled 1000s of miles without broken spokes until now.  Any diagnosis?  NOTE - Trek has issued a recall for this particular wheelset

I just broke a spoke and this is the fourth spoke I've broken in the last 12 months.  This one was very puzzling because it came at the very end of an easy 30 mile (48 km) ride.  I was pedaling very slowly into my driveway when it snapped.   All four have been on the drive side of the rear wheel.  This is a Specialized Allez, one year old, with factory wheels.  I weigh 175 lbs (79 kg) and ride about 2000 miles (3218 km) per year.  Just recreational riding on good road surfaces.  Is this an abnormal rate of breakage?    And if it is an abnormal rate of breakage, what should I do about it?  EDIT:  I took the wheel into the LBS today. They didn't seem surprised by 4 broken spokes in a year, but everyone else is, so I'm going with everyone else. The mechanic checked the tension and they were all correct with one slight exception, so that's not the issue. The wheels are factory wheels and not exactly top flight. The spokes are 1.2 mm rather than 2 mm, so pretty thin. And they're 28 spokes per wheel, so that's cutting it even thinner from what I can gather.   Rebuilding the wheels is $125 each, so that's just not worth it. I can find much better wheels for not much more, so I'm on Amazon looking at wheels while trying not to deplete my life savings. (What some people will pay for wheels boggles the mind.)  I'll have them fix the spoke and check the tensioning so I can sell them and ride until I get replacements.   Gotta buy the tools and learn to replace spokes and true wheels....


I'm using sharelatex and pdflatex as a compiler. I am using the memoir class. (It's for a book.)  At first I used .png images but the compiler always took too long so I converted all my image files to .pdf in order to gain a smaller file size=faster compilation speed and I realized that vector images' quality are better than raster so I want to keep working with vector formats (and I didn't use .svg or .eps because sharelatex doesn't support them).  The image has to fit the page's width margins (for the vector image) or if it does ever exceed, it can be floated(but still centered; and again, I used this trick for png images but they were too big and never loaded properly).  I've tried many solutions, but none of them managed to work. They used to work when the extension was still .png. But once I've switched to pdf they're all broken. (or worked differently so I didn't got my results).  I'm going to add the document's frames so it'll be easier to get an idea of how much the image is off-bounds to the center.  \documentclass[14pt]{memoir} \usepackage[utf8]{inputenc}  \usepackage{graphicx} \graphicspath{ {images/} }  \usepackage[paperwidth=6in, paperheight=9in, margin=0.9in, showframe]{geometry}  \begin{document}  \begin{center} \includegraphics[scale = 1]{001} \end{center}  \end{document}   Which got me this:   \documentclass[14pt]{memoir} \usepackage[utf8]{inputenc}  \usepackage{graphicx} \graphicspath{ {images/} }  \usepackage[paperwidth=6in, paperheight=9in, margin=0.9in, showframe]{geometry}  \begin{document}  \begin{center} \includegraphics[scale = 1]{001_pngversion} \end{center}  \end{document}   Result:   Which gives me the high resolution png version. Somehow, it looks like more aligned to the left...? Maybe it was because it's too big, it exceeded the page limits and couldn't center properly?  I then decided to use the \centering trick and the \linewidth trick to resize it:  \documentclass[14pt]{memoir} \usepackage[utf8]{inputenc}  \usepackage{graphicx} \graphicspath{ {images/} }  \usepackage[paperwidth=6in, paperheight=9in, margin=0.9in, showframe]{geometry}  \begin{document}  \begin{center} \includegraphics[width=1\linewidth]{001} \end{center}  \end{document}   Which got me this, the exact result I was looking for:   Now, let's try the same trick with pdf images:  \documentclass[14pt]{memoir} \usepackage[utf8]{inputenc}  \usepackage{graphicx} \graphicspath{ {images/} }  \usepackage[paperwidth=6in, paperheight=9in, margin=0.9in, showframe]{geometry}  \begin{document}  \begin{figure} \centering \includegraphics[width=1\linewidth]{001} \end{figure}  \end{document}   Results:   Which obtained the same exact result as the FIRST ONE (failed one)  I then tried \begin{figure} \begin{floatrow} or \centerfloat , etc but it still failed. Only worked for pngs...  What I want to achieve is the result I got from the png version, while using .pdf images.  (On a side note, could someone explain the difference in using /centering, /centerline, and /centerfloat? While I was looking for answers concerning centering floating images that surpassed the page's margins. Which one is usually recommended?)

I'm inserting an image with a simple:  \includegraphics[height=5cm]{filename.png}   This results in an image that maintains the aspect ratio, and so gives me something like 6cm width. I only really want the left side of the image though, and would like to crop it to 50% width. Is it possible to do this?  If possible, I'd like to do this in a portable way (i.e. something that other authors of this document won't have to install packages for, and something that works with a reasonably old version of pdflatex - our computers at work are in sore need of an upgrade).


I can switch the screen illumination manually off by pressing Fn+F6 on my laptop keyboard. This is the same as automatically switching it off on idle as it can be set in the power management.   The screen illumination will turn on again if I press any key. I want to keep on typing with a dark screen, i.e. I want to be able to switch it on again only by pressing one specific key combination. (In fact, external illumination e.g. from the sun behind my back can be sufficient to make the screen readable. This is also more eye friendly to me.)  How can I find which software mechanism turns the illumination on again on any key pressed so that I can restrict this mechanism to a particular combination?  This question seems not to be related to screen brighness as it is treated in . I can already adjust the brightness to be quite dark with another keyboard combination, but in the darkest setting /sys/class/backlight/acpi_video0/actual_brightness contains already 0 whereas the screen illumination is still brighter than off. So the switch I think about might be adressed by the Fn+F6 mechanism somewhere else than in the /sys/class/backlight/acpi_video0 tree. The files therein do not change when the screen illumination is turned off completely, only when the brightness is changed but still on.  I'm using MATE/Gnome on an old acer laptop, but hints for other system configurations might be helpful as well.

To work around  (changing LCD brightness via hotkeys impossible), I'd like to have one command line query for increasing and one for reducing the brightness of my LCD. I could then map a hotkey to each one of this queries.  The problem is: I don't know how to increase and reduce the LCD brightness on the command line. Do you?


Is a mirror automatically selected for downloads based on location, or is there a way to do it dynamically?

I want to update my sources.list file with the fastest server from the command line in a fresh Ubuntu Server install. I know this is trivially easy with the GUI, but there doesn't seem to be a simple way to do it from from the command line?


So I'm trying to update from Xcode 7.0.1 to Xcode 7.1 from the App Store. Xcode 7.1 is one of the my available updates. I use the latest EL Capitan 10.11.1. I click the UPDATE button for Xcode 7.1 it says "waiting" and PAUSE then a second later it goes back to UPDATE and nothing installs nothing updates, it's not telling me that I have something else open, which I don't. Is something wrong with App store now? Is there an alternative way to update my Mac apps?

I opened GarageBand for the first time, to find that most of the loops required me to download the Apple Loops from Software Update. I agreed to this.  The App Store opened and gave me the option to install the update from Updates - I clicked Install and waited for the download to complete. It did, and then the installation began.  About half an hour later, the update is stuck on (Installing - Calculating...) This doesn't seem normal - the last time I installed the Loops, they were done in about ten minutes.  Force quitting and re-opening the App Store doesn't help, nor does a reboot. When I open the App Store, the update is still at the same process.  Is there anything that I could do to get the update to finish installing?  Here is a screenshot of the App Store in this state:


I've asked one question (). Someone had kindly given an answer to my question. Consequently, I am alerted through my Stack Exchange inbox, on the upper-left corner. If I so choose, I would also receive an an email in my real email address (e.g. GMail) alerting me that I have a new Stack Exchange message.  However, when that answer-giver edited his answer and made it more helpful, I received no notification in my Stack Exchange inbox, nor did I have an option for receiving emails about this edit.  I had to visit my question manually to see if there was any changes. And, yes, there it was! I really wish we didn't have to manually check our questions to see if any answer-giver has edited his answer.  Could you please allow us to receive email notifications when someone edits their answers to our questions (or to any question we are following)?

If a user asked a question and got an answer which was not helpful.  After sometime the answerer edits the answer with some good content. How the OP will get to know that?  Is it necessary to add comment check my edited answer?  We can say that the OP should refresh the page to find the helpful answer.  Consider if the OP finds the answer as helpful and accepted that. After sometime if the answerer/anyother user edit the answer to change the content which may not solve the issue.   How will it be notified to OP?  currently we are notifying the OP when there is any comment to the queation or any new answers or any comments with the name of OP with @ to any answer.  This will lead the future visitors to confuse and reduce the quality of post.  Can we have a notification to the original poster when the answer to any of his/her question got edited?


I have a few threads in my program - run on Windows and write in C++. How can I know in the end of the running how much CPU time is used by all or one of them?

I once had the task of determining the following performance parameters from inside a running application:   Total virtual memory available Virtual memory currently used Virtual memory currently used by my process Total RAM available RAM currently used RAM currently used by my process % CPU currently used % CPU currently used by my process   The code had to run on Windows and Linux. Even though this seems to be a standard task, finding the necessary information in the manuals (WIN32 API, GNU docs) as well as on the Internet took me several days, because there's so much incomplete/incorrect/outdated information on this topic to be found out there.  In order to save others from going through the same trouble, I thought it would be a good idea to collect all the scattered information plus what I found by trial and error here in one place.


I'm running a buildroot custom linux (kernel 4.9.87) on a custom board based on an Atmel Sama5d2.  I'm trying to configure the network on the eth0 interface using dhcp only at hotplug.  Originally, the interface was configured at boot using auto eth0 into /etc/network/interfaces  I changed it to allow-hotplug eth0 to have the following file  # cat /etc/network/interfaces   auto lo iface lo inet loopback  allow-hotplug eth0 iface eth0 inet dhcp   After this change, udhcpc is not run at boot and is not blocking linux boot for 30 seconds anymore if the cable is not plugged.  However, nothing happens when I plug or unplug the cable.  If I mannually run ifup -a I obtain an IP address on eth0 interface.  From this results, I don't think the problem comes from network configuration but more from handling low level events.  I've tried to monitor the plug/unplug of the cable using udevadm but I can't see any kernel event when I'm pluging and unpluging the cable (but I can see events from usb subsystem for example).  I have also written a udev rule to log events in case udevadm was not relaying this subsystem events.  # cat /etc/udev/rules.d/20-network.rules  SUBSYSTEM=="net", ACTION=="add", RUN+="/test.sh add" SUBSYSTEM=="net", ACTION=="remove" , RUN+="/test.sh remove"    However, nothing is trigerred by this rule neither.    So right now I think I have an issue detecting network cable hotplug.  I could be a kernel configuration mistake as well as a hardware wiring mistake.  I don't really know how the plug/unplug event is detected at hardware level however I think that the event is sent to udev either directly by the driver itself or by one of the numerous kernel frameworks in which it's deployed.  Do you think I may be missing some kernel configuration ?  Do you think it's possible to trace the state cable at a lower level than using udev ? Maybe by directly interfacing with sysfs ?

Is there a workaround for ?  Problem: I want to have a network configuration on Debian with the following properties:   Automatically ifup network interface when a cable is plugged in boots without blocking for a long time when no cable is connected on boot not switching my init system   The standard way to do this would be the following snippet in /etc/network/interfaces:  allow-hotplug eth0 iface eth0 inet dhcp   However, this leads to the problem described in the linked bug report: The boot process blocks for >1min when no network cable is plugged in with the following message:  configuring network interfaces... ifup: waiting for lock on /run/network/ifstate.eth0   A workaround given in  seems to be changing allow-hotplug to auto:  auto eth0 iface eth0 inet dhcp   This effectively makes the boot blocking message disappear, however, the system now blocks right before a login prompt is shown at tty1. This time dhclient is blocking because it tries to get a dhcp reply on eth0, which is not connected, and waits for several attempts to timeout. The login prompt only appears after the dhclient timeouts.  For users with a graphical DE, this might not be a problem, as they don't need to log in on tty1, instead their DE boots and they never see the dhclient message.  Another workaround would probably be to use network-manager. Ideally, I would prefer to not use networkmanager, but as a last resort, I tried that. However, on Debian buster, network-manager's dependency chain conflicts with sysvinit-core, which is my init system.  The last alternative which comes to my mind is to not configure eth0 in interfaces(5). This makes all boot blocks go away, however, I need to manually ifup eth0 after plugging in an ethernet cable.  Any better ideas?  UPDATE: To address the quote from @sourcejedi, "allow-hotplug" is specified to "start interface  when the kernel detects a hotplug event from the interface" in the Debian docs under . Related questions:  and


I'm new to the C language and Loadrunner.  How do I do a string concatenation in C.  Pseudo code:  String second = "sec"; String fouth = "four"; System.out.println("First string" + second +"Third" + fouth);

I'm working in C, and I have to concatenate a few things.  Right now I have this:  message = strcat("TEXT ", var);  message2 = strcat(strcat("TEXT ", foo), strcat(" TEXT ", bar));   Now if you have experience in C I'm sure you realize that this gives you a segmentation fault when you try to run it. So how do I work around that?


Prove that  $(a+b\sqrt[3]{2}+c\sqrt[3]{4})^{-1}$ with $a,b,c∈Q$ is a number of the form $d+e\sqrt[3]{2}+f\sqrt[3]{4}$ with $d,e,f \in Q$  I'd like to do this without using too much fancy field-theoretic machinery.

How can I prove that $\frac{1}{a+b\sqrt[3]{2}+c\sqrt[3]{4}}$ is of the form $a+b\sqrt[3]{2}+c\sqrt[3]{4}$ (i.e. that $a+b\sqrt[3]{2}+c\sqrt[3]{4}$ is a field)  for all rational $a,b,c$ and $a+b\sqrt[3]{2}+c\sqrt[3]{4} \neq 0$?


I'm trying to increase the height of a div to follow the bottom of the page, so far I've tried using height: 50vh but this causes the height to increase proportionally and not in parallel.  If you increase the height of this snippet (in full screen), you'll see what I mean. I basically want the bottom of the coloured div just above the word 'Portfolio', at the bottom of the screen, no matter how much height the page has.    #header-bg {   height: 50vh;   background-color: peachpuff; }  #portfolio {   width: 100%;   text-align: center; }

     Portfolio

I am working on a web application where I want the content to fill the height of the entire screen.  The page has a header, which contains a logo, and account information. This could be an arbitrary height. I want the content div to fill the rest of the page to the bottom.  I have a header div and a content div. At the moment I am using a table for the layout like so:  CSS and HTML    #page {     height: 100%; width: 100% }  #tdcontent {     height: 100%; }  #content {     overflow: auto; /* or overflow: hidden; */ }

...

...

     The entire height of the page is filled, and no scrolling is required.  For anything inside the content div, setting top: 0; will put it right underneath the header. Sometimes the content will be a real table, with its height set to 100%. Putting header inside content will not allow this to work.  Is there a way to achieve the same effect without using the table?  Update:  Elements inside the content div will have heights set to percentages as well. So something at 100% inside the div will fill it to the bottom. As will two elements at 50%.  Update 2:  For instance, if the header takes up 20% of the screen's height, a table specified at 50% inside #content would take up 40% of the screen space. So far, wrapping the entire thing in a table is the only thing that works.


I have a Ubuntu Linux Server 14.04 LTS which is running a Minecraft server. I want it to reboot every 6 hours. I have that now and after the reboot, it starts the Minecraft server.  Now what I want. I have the server console in a screen session named cds_screen. Is there a way to do something like screen -d -r cds_screen && say Server is restarting && sudo reboot? The server runs as jebg user and not as root so can anyone help me?

I'm trying to run a minecraft server on my unRAID server.  The server will run in the shell, and then sit there waiting for input. To stop it, I need to type 'stop' and press enter, and then it'll save the world and gracefully exit, and I'm back in the shell. That all works if I run it via telnetting into the NAS box, but I want to run it directly on the box.   this is what I previously had as a first attempt:  #define USER_SCRIPT_LABEL Start Minecraft server #define USER_SCRIPT_DESCR Start minecraft server. needs sde2 mounted first cd /mnt/disk/sde2/MCunraid screen -d -m -S minecraft /usr/lib/java/bin/java -Xincgc -Xmx1024M -jar CraftBukkit.jar   MCunraid is the folder where I have the Craftbukkit.jar and all the world files etc. If I type that screen line in directly, the screen does setup detached and the server launches. If I execute that line from within the script it doesn't seem to set up a screen  for stopping the server, I need to 'type' in STOP and then press enter. My approach was  screen -S minecraft -X stuff "stop $(echo -ne '\r')"   to send to screen 'minecraft' the text s-t-o-p and a carriage return. But that doesn't work, even if I type it directly onto the command line. But if I 'screen -r' I can get to the screen with the server running, then type 'stop' and it shuts down properly.  The server runs well if I telnet in and do it manually, just need to run it without being connected from my remote computer.


I can not Edit my comment which was posted 20 minutes ago. I can only delete it.  If I add a new comment I can delete or edit it.  Is this a bug or feature? I don't see why someone should not be able to edit his/her own comments.  I usually double check my posts before I put a comment or an answer but I would like to correct a possible typo to keep the posts clean.

Across the Stack Exchange network you may leave comments on a question or answer.  How do comments work? What are comments for, and when shouldn't I comment? Who can post comments? Who can edit comments? How can I format and link in comments? My comment doesn't contain some of the text I typed in it; why? My comment appears to be long enough, but I can't post it because it's too short; why? Who can delete comments? When should comments be deleted? Why can't I comment on specific posts even if I have enough reputation to comment? When can comments be undeleted? What are automatic comments? How can I link to comments? Anything else I should know about comments?  Also see the FAQ articles on  and .


I have MacBook Pro Retina Mid 2014 with Catalina installed. Initially my Mac is randomly shut down and later it shutdown every time I logged on to the Mac. It will display the desktop for a few seconds then shut down.  The Mac keeps shutting down in the Safe mode and also Recovery mode. But when I run Apple Diagnostic it says that there no errors found.   When I look in the log from advice in comments, I get "shutdown cause -128"  Do you think my logic board is broken or this is related to something else?

2.3 Ghz Intel Core i7 8GB DDR3: Was running NetAdmin Pro which is monitoring  my office LAN, processors consumption was at  ~15 - 20%. Simultaneously I ran WiFI Explorer,  3.7% no more than 5% CPU usage. And I was  updating Xcode to v 7.3.1 and was browsing and  watching video from playground.ru Watch the videos until half of it (20mins) the Video froze I moved the mouse and turned out  the whole OSX is frozen. littleSnitch v 3.7 has no reaction I immediately pull the Ethernet adaptor and  MacBook just went to black screen. I then  switch off the wireless router. (My MacBook Pro  is connected to the network via Ethernet  adaptor and via WiFi router bearing different IP, I was thinking of cutting both network  communication, in case it was an intrusion) MacBook just restarted itself to login screen,  after 15-20 sec of black screen and total  silence) I again restarted and booted into Recovery  mode use disk utility. After completing disk  check. Login and previously opened programs resume  back (NetAdmin Pro, WiFi Explorer, Yandex  browser, Activity Monitor and AppStore) AppStore doesn't resume the download  everything else is functioning normally and in Addition I have got my calendar open after login (I did not launch accidental nor was it set to  start with system login)   Question 1: Are there any way to know what was happening and what was OS El Capitan last reaction before it froze and rebooted?  Question 2: Are there any software better than "Console" v10.11 to interpret what was going on before it crashes?  P.S. Thank you in advance, I will try to upload the Console messages later from the MacBook Pro    DDT-2:~ Chaleune$ syslog | grep -i "shutdown cause"  Jun 22 14:15:37 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  Jun 22 20:34:46 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 23 15:18:23 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  Jun 24 17:58:32 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 24 20:09:52 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 24 22:58:15 localhost kernel[0] <Notice>: Previous shutdown cause: 5Jun 25 14:43:36 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  Jun 25 21:55:31 localhost kernel[0] <Notice>: Previous shutdown cause: 3  Jun 25 22:20:57 localhost kernel[0] <Notice>: Kext com.apple.driver.AppleOSXWatchdog failed to load (0xdc008012).Previous shutdown cause: 5  Jun 26 10:18:44 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 26 12:09:45 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 26 18:00:31 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 27 13:05:58 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  Jun 27 22:56:11 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 28 14:18:27 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  *Jun 29 18:56:21 localhost kernel[0] <Notice>: Previous shutdown cause: -128*  Jun 29 23:31:22 DDT-2 kernel[0] <Notice>: Previous shutdown cause: -128      shows the following   dsIllInstErr                  = 3,    /illegal instruction error/ dsChkErr                      = 5,    /check trap error/ userCanceledErr               = -128    gave the following interpretation:   03 Illegal Instruction The computer has a specific vocabulary of machine language instructions it can understand. If a computer tries to execute an instruction that isn't in its vocabulary, you see this error code. It's less likely than error 02, but still very common. 05 Range Check Error Programmers can use an instruction in the Motorola 68000 to check if a number is within a certain range. This error indicates that the number tested isn't in the specified range. -128  userCanceledErr         User canceled an operation


first off, I've watched like 7 youtube videos, read a bunch of articles, and the explanations for why myelination actually increases action potential propagation differ each time are very vague. I've read and heard that because action potentials only occur on the nodes of Ranvier, that it simply takes less time for them to travel down an axon. I get that, but I was under the impression that increased +ve charge = further generation of action potentials. if that is the case, wouldn't that mean that myelination should slow it down as there is less +ve charge influx? I understand that it takes time for action potentials to be generated, but is the variable affecting the rate at which they occur not the influx of +ve charge, and wouldn't this positive charge be less if there are fewer action potentials generated? it's not like myelination decreases the time taken for particular na+ channels to open, right? ftr, I'm not doubting that myelination speeds up action potential propagation, I just don't get it and the explanations are contradictory (nothing that I've mentioned here is contradictory to my knowledge FYI, I just mean that I have heard other contradictory explanations). I understand that it insulates the neuron, thus preventing k+ leakage. Does the insulation possibly increase the rate of propagation by decreasing the ability of extracellular ions from interacting with intracellular neurons? I would understand that I suppose since then there wouldn't be positively charged particles on the exterior exerting electric force upon the intracellular +vely charged particles, thus making it easier for +ve charge to spread throughout the negatively charged axon. even if there is any truth in that, could that possibly compensate for the decrease in intracellular sodium that the decreased amount of na+ influx channels would imply? thanks to anyone who responds! a long one for sure, lol.

How does spacing apart sodium and potassium channels allow the action potential to travel faster down the axon? This is the reason always cited for saltatory conduction and myelination, but my mental model of conduction tells me that the density of ion gates along the axon should not affect the speed of the AP.   To illustrate, consider a myelinated axon. A wave of Na$^+$ from action potential site 1, a node of Ranvier, rushes into and quickly diffuses down the axon. (It travels in both directions, but backwards is still in the refractory period.) It diffuses through the myelinated region, its concentration always diminishing. Before it attenuates too much, however, it happens upon node of Ranvier 2, where it triggers another action potential. A new wave of Na$^+$ rushes in and the cycle repeats. This should be plain so far.  Now imagine that there is actually a node of Ranvier halfway between node 1 and 2, called node 1.5. The wave of Na$^+$, on its way to node 2, happens to trigger an action potential at node 1.5, from which a wave of Na$^+$ pours in and either boosts the original wave or replaces it by taking its momentum. Now the reinforced wave proceeds to node 2 and triggers it just as soon as, perhaps even sooner than, if node 1.5 had not existed. Repeatedly insert nodes at higher densities until the situation is simply lack of myelination, and we conclude that unmyelinated axons can transmit an action-potential-triggering wave of Na+ as fast as or faster than a myelinated one.  In short, my point of confusion is this: I cannot see how a higher density of gated channels can possibly slow down the wavefront of Na+ that triggers action potentials. If anything, the additional influxes of Na+ should speed up the all-important wavefront, assuming that new waves really "either boost the original wave or replace it by taking its momentum", and also assuming that the wavefront of Na$^+$ is really all-important for signal transmission, and also assuming that the mere presence of (voltage?) gated ion channels in the membrane does not significantly retard the wavefront.  But the usual explanation for why saltatory conduction is faster than continuous conduction (a fact I hope is empirically and unambiguously established) relies on the putative slowing effect of ion channels on the signal fore. Please explain this effect in more detail, if it is not a misconception.


I am working on a thesis, I use report document, I need to format a list of figures as shown in the image:   The same heading should be repeated in all LOF pages. The "List of Figure" should be in centered and 16px.  Thanks

I'm new to LaTex, so please bear with me if this is a newbie question. I am using a template where \listoftables is defined as follows:  \def\listoftables{\@restonecolfalse\if@twocolumn\@restonecoltrue\onecolumn   \fi\chapter*{List of Tables\@mkboth    {LIST OF TABLES}{LIST OF TABLES}}    \addcontentsline{toc}{chapter}{List of Tables}\@starttoc{lot}\if@restonecol   \twocolumn\fi}   When I add \listoftables to my document, I get something like this:    What I'd like to add is something like this:    How do I add the header row at the top for each column in the list of tables? Thank you in advanced for your answers and suggestions!


My end game is to get my computer to make all of the sounds from my all time favorite video game from the 90's. I've already found the ogg file but now I want it to play every single time I type ANYTHING in the terminal.   For example: "fjeocjrigfjrig" would play the specified sound 14 times as I type. The clip for this is only about .3 seconds long. Is this possible?  I'd only like for this to happen while in the terminal. My google-fu turned up with nada.

Since I switched to Ubuntu 12.04 I'd only missed one thing.  A program which could launch typewriter sounds while typing. For instance, in Windows I used this:  for a long time.  I learned then that this writing program:  had the sounds but only for the program itself.  However, sometimes I'm writing an email, writing on the web or doing more complex writing tasks in LibreOffice - all places where these long missed typing sounds don't apply.  Does any of you know of any plans in the community of the sound bit - typing sounds - as an independent program or applet to be fetched in the Ubuntu Software Center soon?


Why does inserting a dielectric of dielectric constant $k_e$ have an effect of increasing the distance from $r$ to $r+t(\sqrt{k} -1)$ in Coulomb's law of electrostatics (where $t$ is the thickness of dielectric slab)? Shouldn't the dipole forces cancel out?

I am given two charged particles of same charge at a distance of $r$. They initially apply force $F$.  Now an infinite dielectric (of dielectric constant $4$) of width $\frac{r}{2}$ is introduced between the particles. What will be the new force?   I find this problem confusing because I have only been told about forces when its either fully dielectric or fully vaccum given by Coulomb's law. How do we get forces when only partial space is dielectric?


Please, don't mark this post as a duplicate! I already checked all the same posts about this topic on this website and can say that all answers really answer nothing. I have 256gb SSD, and 85 (!!!) of them are in the Other storage. It is ridiculous. Those files don't exist. I already used OmniDiskSweeper - it does not show those files. It shows only 135gb and that's all, yep. 20gb for MaOS and other 85 are just gone forever. Don't suggest me using CleanMyMac please, I used it, it cleaned 1 Gb of junk files, clearly not 85... It seems that there is no point of buying 256 and for the next Mac I'll have to buy 512

Every few days I get notices on my MacBook that it's running or run out of hard drive space. Curiously, restarting the computer will enable me to recover gigabytes of space (this past time, it was able to recover about 2.2GB). However, I can't identify anything in my personal activity that consumed that space.  It's possible that it's a rogue iTunes podcast or a huge software update that my Mac is automatically downloading - would either of these reclaim the space upon a restart?  One possibility that I can think of is that FileVault has some sort of disk leak, allocating but not freeing files. Does this make sense? Is there a tool that I can run to determine where this space is going? Assuming it is FileVault, should I try to disable it? What's the best way to turn of FileVault on a nearly full computer?


I have some issues in my html code. but unable to post question as it said "it looks like your post is mostly code. please add some more details".  how can we overcome this issue.  Thank you...

How do you solve the following error when creating a simple post?     It looks like your post is mostly code; please add some more details


I'd like to create a partition where to install Ubuntu in a Dell inspiron 6000 with WinXp OS already installed. What is the minimal amount of disk space required for booting the system? Then I'd create another partition for the data.  I tried to install Ubuntu alongside WinXP without creating a dedicated partition but the grub install failed at the end.

I know how much space is required to install Ubuntu.  How much space does a Ubuntu installation take up on the disk?


Sometimes I see them with methods, classes etc.  What does it do?  When should i use them? Example:  [Obsolete] public static void MyMethod() {     //some code }

What are attributes in .NET, what are they good for, and how do I create my own attributes?


I've a question about upgrading my old Ubuntu 11.04 to the latest version. How can I do this without loosing my settings and data?

What are the different ways I can use to upgrade Ubuntu from one release to another?


I am currently using rainfall data in determining rainfall patterns. But when I use Polygonize, the values on the attribute table of the created vector file were rounded off to the nearest whole number. I want to keep the decimal number but iI can't find any option to do that.

I am working on QGIS. I have a raster of EVI, in which values are comprised between 0 and 1. I need to vectorize this raster in order to make an intersection with another vector. My issue is that when I vectorize my raster, the values are either 0 or 1, but I want the values detailed between 0 and 1. The best would be to have the values every 0.1 (0.1, 0.2, 0.3, ...). Do you have any idea of how I can proceed? I was thinking that I could multiply the values of the raster by a hundred, but is that even possible?


Let $X : C^{\infty}(\mathbb{R}^n) \rightarrow \mathbb{R}$ be a derivation, so i.e. linear and satisfying the Leibniz Rule  $$X(fg)=X(f) \cdot  g(a)+X(g) \cdot f(a)$$ for some fixed $a \in \mathbb{R}^n.$ Then I would like to see that $X = \sum_{i=1}^{n} a_i \frac{\partial}{\partial x_i}|_a.$ So I want to see that $X$ is essentially a directional derivative.

At the moment I'm studying manifolds and in the definition of tangent space, the notion of derivation was used in the material I'm reading. I asked here about the matter and it was told me that it's not necessary to have a complete background in abstract algebra to proceed but instead just understand the definition of a derivation. If I understood well a derivation is a way to extract the main properties of a differential operator: linearity and obeying the product rule. This line of thought leads me to a doubt: every differential operator should obey the product rule, but if a operator is linear and obey the product rule is possible to conclude it's a differential operator (it can calculate rates of change, be used to construct the taylor approximation to the function and every other properties we expect from a derivative)?


skip 1st value of loop. i'm trying getting youtube video search data from api with php in loop a got 2 video i want show only 2nd one and skip 1st one.  $grab=grabe('https://www.googleapis.com/youtube/v3/search?key='.$key.'&part=snippet&order=relevance&maxResults=2&q='.$q.''); $json = json_decode($grab); foreach ($json->items as $sam){     $link= $sam->id->videoId;   i got '.$link.' 2 video , bout i want show 2nd video skip 1st 1 how it possible

I have the following code:  if ($_POST['submit'] == "Next") {     foreach($_POST['info'] as $key => $value) {         echo $value;     } }   How do I get the foreach function to start from the 2nd key in the array?


I would like to bind "enter" to a combination of keys at the left side of my keyboard. How do I go about doing this? (I would like the combination of keys to be Ctrl+Shift+Q, or maybe there is a better one out there?). It's sort of becoming tedious to reach around or let go of the mouse from my right hand whenever I enter something.

I recently upgraded to Snow Leopard, from Leopard and I was using an awesome app called  that let you remap your keys, set scripts/macros and even had repeat functionality.   However, this app doesn't seem to be in active development anymore, and 10.6 broke the ability to bind certain modifier keys (Shift) with other keys.   I totally miss things like Shift+Insert for paste (Linux/Windows), setting Ctrl+Shift+Esc for Activity Monitor, and Ctrl+Alt+Del for the login window.   So, how can I achieve this instead?


There used to be an export to PDF feature on Careers. I can't seem to find it anymore.  Where is it? Is it gone? If so, why? It was awesome! Can we get it back, please?

There used to be an option to convert my stackoverflow careers profile to a PDF file, which is a great feature.  However, I can no longer find an option to do this. Was it removed?


When using \rowcolors to alternate row coloring, some vertical lines are missing in the restulting table.   \documentclass{scrreprt} \usepackage[table]{xcolor}  \begin{document} \begin{table} \rowcolors{2}{gray!25}{white} \begin{tabular}{l|ccc|cc|ccc|}            & A & B & C & D & E & F & G & H \\\hline    Verfahren  & p & a & p & a & a & a & a & a \\ Verfahren  & p & a & p & a & a & a & a & a \\ Verfahren  & p & a & p & a & a & a & a & a \\ Verfahren  & p & a & p & a & a & a & a & a \\ \end{tabular} \end{table}  \end{document}     If I manually insert  \rowcolor{gray!25} for every other row, the lines are correct for the "white" rows (since they are not explicitly set to to white as in the \rowcolors case)  Am I missing something?

I'm using the xcolor package to colour the top row in a table. This is displayed properly using PDF viewers such as Preview or Skim (Mac). But using Adobe Reader 10.1.3 (either Windows or Mac) doesn't display the table line properly.   But removing the colouring for the table fixes it. Here is the example that works as expected:  \begin{table} \caption{Table showing Feature 5's Functional Tests} \hspace*{-0.5in} \begin{tabular}[h!]{|p{0.6cm}|p{4cm}|p{5cm}|p{4cm}|p{1.5cm}|} \hline {\bf Test ID } & {\bf Task } & {\bf Expected} & {\bf Actual} & {\bf Outcome} \\ \hline    5.1 & Something &  Something & Something &  Success \\ \hline    5.2 & Something &  Something & Something &  Success \\ \hline    5.3 & Something &  Something & Something &  Success \\ \hline    5.4 & Something &  Something & Something &  Success \\ \hline \end{tabular}  \end{table}   And here is the example with a coloured row:  \begin{table} \caption{Table showing Feature 5's Functional Tests} \hspace*{-0.5in} \begin{tabular}[h!]{|p{0.6cm}|p{4cm}|p{5cm}|p{4cm}|p{1.5cm}|} \hline \rowcolor{gray!25} {\bf Test ID } & {\bf Task } & {\bf Expected} & {\bf Actual} & {\bf Outcome} \\ \hline    5.1 & Something &  Something & Something &  Success \\ \hline    5.2 & Something &  Something & Something &  Success \\ \hline    5.3 & Something &  Something & Something &  Success \\ \hline    5.4 & Something &  Something & Something &  Success \\ \hline \end{tabular}  \end{table}   Removing the \rowcolor{} command replacing it with \cellcolor{} creates the same view. Any idea how to fix this?  I've tried printing it out of Adobe and the lines print fine, but as this will be read on as a soft copy it's pretty important. .  Any idea how to fix this?


Let  $ C^1[0,1]$ be the normed space of continuously differentable functions on $[0,1],$ with $||x||=\max_{t\in [0,1]} |x(t)| $. Prove that  $ (C^1[0,1],||.||)$  isn't a Banach space   I think we need to construct a Cauchy sequence in the space which doesn't converge in the space but i don't know how to construct this sequence. I'm stuck here

Given the normed space $C^1[0,1]$ of differentiable functions with continuous derivatives on $[0,1]$. The norm is defined as $$\|x\| = \max_{[0,1]} |x(t)|$$ I'd like to prove that the given normed space is not a Banach space. In the attempt of solving this problem, I have thought about the possibility to construct a Cauchy sequence in the space which doesn't converge in the space. However until now I haven't got any idea. Then I proceeded to think about constructing an equivalent norm to the given one where the space can be easily proven to be not a Banach space. However, I have got nothing either. Now I'm stuck without a clue. Please give me a hint to a correct direction. Any help is greatly appreciated.


I've read in Wikipedia that:      "if a liquid is contained in a cylindrical vessel and is rotating around a vertical axis coinciding with the axis of the cylinder, the free surface will assume a parabolic surface of revolution known as a paraboloid. The free surface at each point is at a right angle to the force acting at it, which is the resultant of the force of gravity and the centrifugal force from the motion of each point in a circle."   Why does it form a paraboloid? My particular difficulty is that all points are supposed to be acted upon same forces so I don't understand the reason they are rotating at circles having different distances from the axis of rotation.

I have been wondering why a fluid in a rotating container has a parabola shape? Is it possible to prove this mathematically?


Say I'll start writing  sudo cp /etc/var/more/evenMORE/fileABC   and as the target of the copying, I'd like to define the same folder, except just a different filename (whether it is a new name like "randomNAME" or an iteration of the file "fileABC-backup01" shall be irrelevant). How can I reuse the input file so that I do not have to write it out again? Is this even possible?

I know how to rename files in Unix:  $ mv ~/folder/subfolder/file.txt ~/folder/subfolder/file.sh       ^-------this part------^    ^------this part-------^   It takes too long time to repeat ~/folder/subfolder/file twice.  Is there a quicker way?


I'm new to blender, I only used Maya some years ago...  I'm trying to make the stair in the picture but I don't know how to do the railing. I know I have to use a curve and then extrude a circle in it but how to?    Thanks.

How can I model this irregular curved torus shape that is in the back of this dolly? I know how to cut apart a torus but I think what I need is for a torus to be extruded along a curve line.


Hard drive crashed on my 4+ year-old laptop.  Decided to try Ubuntu 12.04 desktop instead of reinstalling Vista.  Installed a new 500 GB drive in the laptop, and booted using a newly created Ubuntu flash drive.  Used gparted to create a single ext4 partition.  Rebooted, then tried the "Install to hard drive" option that came up during the boot process.  I got a btrfs message, then a checksumming message, then a series of repeating "asking for cache data failed" and "Assuming drive cache: write through" messages.  Can anyone tell me what these messages mean?  How do I get past this problem?

I would like to see a full how-to guide on how to install Ubuntu.


I have a render array for my custom form, which acts as a "Like" button for articles (but with custom functionality for our client). The button is defined like so:  ...     $form['like_btn'] = [       '#type'   => 'button',       '#markup' => '<img src="/path/to/like-icon.svg" width="32">',       '#attributes' => [         'class' => ['like'],         'id'    => ['like-btn'],       ],       '#ajax'   => [         'callback' => '::updateLikesCounter',         'disable-refocus' => FALSE,         'event'    => 'click',         'wrapper'  => 'like_counter',         'progress' => [           'type' => 'none',         ],       ],     ]; ...   However, this renders the button as <input type="submit"> rather than a <button> element.  How can I make the "button" render element type utilize the <button> HTML element instead? Or, which render element #type should I use instead?

Is it possible in Drupal 8 to change a regular form submit button from Drupal into a button tag?  This is the output I need to achieve:  <button type="button" class="search-box__button">   <svg class="icon search-box__open">     <use xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="/build/img/svg-sprite.svg#icon-search"></use>   </svg> </button>


Recently I registered a .com address for a business. In the modern world (year 2018) why would I need to add and maintain the www. subdomain of my domain?  I'm mostly interested in benefits of the subdomain. Thinking if I should bother doing the www.EXAMPLE.com -> EXAMPLE.com redirection.  UPD: I am not asking about SEO, not asking personal opinions, not asking tech details. The linked "duplicate" question is very different to my question.

What are the pros and cons of having http://www.example.com/ vs http://example.com/?  For example a problem I'm aware of is that if I use a domain without www I can't set a cookie for the current subdomain only (since there is no subdomain), and the cookies I set will be sent to all subdomains.


There is a fault in the dedicated graphics card, and so my laptop is almost unusable. I am thinking of getting it fixed in the warranty. However the only problem is that Dell's complete care warranty means almost surely formatting the whole system before fixing the hardware issue. And that's undesirable because I have installed many softwares in KUbuntu 14.04 and customized it to a great extent.  So my question is, how do I take a complete backup of the Linux setup?  I have /root and /home on different partitions, and there's a separate partition for swap. There are also 3 other partitions, one of them for windows (I don't care much about it though, I hardly ever use it), and other for storing general purpose files.   By complete backup I mean I store it on an external hard disk drive, and restore the Linux setup to its current state after the graphics card problem is fixed by Dell under warranty.  Tl;dr: how do I take complete backup of KUbuntu 14.04 including all softwares and customization and restore it later?  Edit: after the hardware fix, Dell will give my laptop in a factory condition, with only one partition of 500 GB, which has only windows in it. I'll manually restore the data in the remaining partitions, I'm just clueless about backing up and restoring Linux.

If I want to make a backup of my entire OS (including but not just my home directory), how do I go about this?    Is it as simple as backing up everything in / and then when if I suffer a crash, just copying the files back over? Will this cover grub, and how do I actually do this when the system is inoperable?


I am wondering if there is a way to get advice\feedback here about the following: I am about to start a MS physics program. I am interested in quantum computing and my department has the option of pursuing a thesis as a graduation route. I am new to this topic and would like to see if I can get some suggestions - papers, books, topics, etc - to think about to be able to craft a project in quantum computing for a beginner like me that can in a two-year period scale into something with more insight in the topic.   Thank you.

I am a computer science student and am currently searching for resources from where I can learn about quantum computers, quantum computing models, their working principles, their gates and some simple quantum algorithms.


I have a 9th level bard. Hypothetically, if when I reached 10th level I took a level in cleric and chose the life domain, so I would be bard 9/cleric 1. The multi-classing rules state "When you gain a new level in a class, you get its features for that level" and then lists a bunch of exceptions, none of which apply to this situation. In the cleric class, at level 1 you take a domain. The life domain has an ability called disciple of life which reads  Also starting at first level, your healing spells are more effective. Whenever you use a spell of 1st level or higher to restore hit points to a creature, the creature regains additional hit points equal to 2 + the spell's level."  Note that it says healing spells, not specifically cleric ones. It would seem the RAW here is that this would apply to my bard spells as well. So my mass cure wounds (which is 5th level and I would not be able to know as a cleric spell but which I do know as a bard spell), would heal everything an additional 7 points. Is this how multiclassing works? It seems like my best multi-class option if it does (although I'd probably wait until 11th level since level 10 bards get awesome stuff). Am I missing something?

I play a D&D 5e campaign. My Tempest Cleric is about to take his first multi-class dip into Wizard.   Am I able to use my Cleric class and domain features on my Wizard spells, and vice-versa? Both at the same time?  Examples:   When I cast Shocking Grasp (Wizard spell), can I use my Channel Divinity: Destructive Wrath to maximize the lightning damage and then use Thunderbolt Strike (another domain feature) to cause the target to be pushed back 10 feet? When I roll damage on the weapon attack made for Booming Blade (Wizard spell), can I also add the 1d8 or 2d8 Thunder damage from my domain’s Divine Strike feature to the total? If I study the School of Abjuration, is my Arcane Ward replenished if I cast Freedom of Movement (Cleric abjuration spell, not on Wizard spell list)? If I study the School of Evocation, can I cast Shatter (Cleric domain spell) and apply both Sculp Spell (Wizard School of Evocation feature) to avoid hitting my allies in the blast radius and ALSO use Channel Divinity: Destructive Wrath to maximize the thunder damage?


Let $S$ be the relation on $\mathbb{N} \times \mathbb{N}$ defined by $(a,b)S(c,d)$ if and only if $ad=bc$. Prove this is an equivalence relation on $\mathbb{N} \times \mathbb{N}$.  I think I've found this to be reflexive and symmetric, but I'm stuck on transitivity. Can someone check my work so far and assist with testing transitivity?  Reflexive: Let $(x,y)S(x,y)$. Then $xy = yx$. So $S$ is reflexive. Symmetric: Suppose $(a,b)S(c,d)$. Then, $ad = bc$. Therefore, $da = cb$ and $cb = da$. Therefore, $(c,d)S(a,b)$. Thus, $S$ is symmetric.  Transitive: Suppose $(a,b)S(b,c)$. Then $ac = bb$.   This is where I'm stuck. Any ideas?

Let $r$ be a relation on $A \times A$ such that $(a,b) r (c,d) \iff ad = bc.$ How can I show that this relation is transitive, ie. $(a, b)r(c,d)$ and $(c,d)r(e, f) \implies (a,b)r(e,f)$?  I tried to say that $(a,b) r (c,d)$ means that $c=ka$ and $d=kb,$ $k$ a coefficient, such that $ad = bc \iff akb = bka,$ and going on from there, but I'm not sure this is valid for all values of $a, b, c,$ and $d$. How can I show the transitivity of the relation?


I am working on a Problem from Casella Berger. It reads the following: Let $X_1, ...., X_n$ be a random sample from a population with pdf $$ f(x)= \theta x^{\theta -1}$$ with $ 0 <x<1, \theta>0$ Is $\sum X_i$ sufficient? By factorization I found that $\prod X_i$ is sufficient, but this does not disprove the sufficiency of the sum? To disprove by the conditional distribution I would have to know the distribution of the $ \sum X_i$, which I don't know. I found out that one Idea would be to show that $\sum X_i$ is not a function of the minimal sufficient statistic. But I have no clue how to find that. Many thanks

This problem comes from , who do not rigorously demonstrate (in their solution key) that the statistic is not sufficient.  Let $X_1,\dots,X_n$ be a random sample from a population with PDF $f(x|\theta)=\theta x^{\theta-1} \cdot 1_{\{x\in(0,1)\}}$ for $\theta>0$. Show that $\sum_i X_i$ is not sufficient for $\theta$.  If you write out the PDF $p(\vec{x}|\theta)$ of the random sample, it is clear by the factorization theorem that $\prod_i X_i$ or $\sum_i \log(X_i)$ are sufficient for $\theta$; the PDF $p$ also suggests $\sum_i X_i$ is not sufficient for $\theta$. However, to rigorously demonstrate this, we need to analyze $p(\vec{x},\theta)/q(T(\vec{x},\theta)$, where $p$ is the distribution of sample $\vec{x}$, $q$ is the distribution of the statistic $T(\vec{X})=\sum_i X_i$. But finding the distribution of $T(X)=\sum_i X_i$ seems impractical. I have observed that $f$ is the PDF of a Beta($\theta$,1) distribution, but checking online, the distribution of the sum of Beta random variables doesn't appear to have a closed form. Are there any alternative routes (e.g., showing there is no factorization involving $T(\vec{X})$)? Did C&B leave out a full explanation that $\sum_i X_i$ is not sufficient because none actually exist?


Is it possible to create an electromagnetic wave of near zero frequency?   An electromagnetic wave carries energy. If we can make the frequency of an EM wave vanishingly small and make it practicality DC, will it also carry energy? I don't think it is possible. Hence there should be some fundamental limit on the minimum frequency of an EM wave.   Is there any such thing?

This asked:   And also this:     The second question is contradictory; maximum frequency -> minimum wavelength.   I am asking the very opposite;    What is the minimum frequency and maximum wavelenght of electromagnetic radiation?   The lowest measured/defined seems to be 3 Hz;  Which means a wavelenght 1/3 of the speed of light; ~100 000 000 m.   But this can't be the physical limit for the wavelenght. Does such a physical limit for the wavelength exist? (Similar limit like the speed of light is for velocity).


I've got a handleful of macs (all with unique names) and on occasion it prompt a notice about saying another computer on the network as this name and adds a (2) or (3) to my mac.    How can I set the host name from the command line?

For three days straight, I have connected to the public WiFi network at my local library. Each day, I have seen a different prompt in Terminal. Here are some of the prompts I've seen:  zp-pc:~ russell$ mary-pc:~ russell$ normob05:~ russell$   I have check under System Preferences -> Sharing, and my computer name is "Russell's Mac". Also, I set the DHCP Client ID to "RUSSMAC" under System Preferences -> Network -> Advanced -> TCP/IP, but I still see the random host names at the Terminal prompt.  Why is my computer name changing every day?


I am having this code inside my after insert trigger code block.    if(Trigger.isInsert && Trigger.isAfter) {     List <History__c> historyRecords = new List<History__c>();     History__c newhistory = new History__c();     for(Case cs: trigger.new)     {       newhistory.Name='New Case Opened';       newhistory.Modified_by_User__c=cs.LastModifiedBy.Name;       newhistory.Time_and_Date__c=cs.CreatedDate;       newhistory.Case_Number__c=cs.CaseNumber;       historyRecords.add(newhistory);     }      insert historyRecords;     }  The problem is when new record gets created, the LastModifiedBy.Name is coming as null. Same logic when I tried from Anonymous Code block, was working fine. Why is it happening so?

This is a canonical question and answer developed by the community to help address common questions. If you've been directed here, or your question has been closed as a duplicate, please look through the resources here and use them to shape more specific questions. To browse all canonical questions and answers, navigate to the  tag. This question and answer is owned by the community! If you can improve it and make it more useful, you're welcome to edit it. I am building a trigger, a unit test, or other Apex code. I'm working with sObject records, and trying to access related record information. For example, I might have a structure like this: Account a = new Account(Name = 'Test'); insert a;  Opportunity o = new Opportunity(Name = 'Donation', AccountId = a.Id); insert o;  System.assertEquals(o.Account.Name, 'Test', 'Correct Account associated'); // Assertion fails!  Or, in a trigger, I might be aiming for something like this: trigger ContactTrigger on Contact (after insert) {     for (Contact c : Trigger.new) {         if (c.Account.Name == 'Test') {             // Take some action here         }      } }  Why doesn't this work? Why am I getting null values, or NullPointerExceptions?


I'm currently facing some issue in determining what statistical test might be best to adopt to determine whether or not three datasets are significantly different from each other. I have the following datasets of probabilities observed within my system: prob355 = [0.06672, 0.07473, 0.14813, 0.25516]; prob532 = [0.07226, 0.08718, 0.09631, 0.14276]; prob1064 = [0.05979, 0.09020, 0.10891, 0.11307]; Within these datasets, each entry corresponds to a probability obtained under certain conditions such that within the dataset the conditions for prob355(1) ≠ prob355(2) prob355(3) ≠ prob355(4). Between the datasets they have been ordered such that prob355(1) = prob532(1) = prob1064(1). Within these datasets each and every observation has its own errors/standarddeviation/noise. Such that the datasets are accompanied by the following errors/standarddeviation/noise in the observed probabilities: model_error_355 = [0.03255, 0.03986, 0.01321, 0.01928]; model_error_532 = [0.01370, 0.00880, 0.00856, 0.04257]; model_error_1064 = [0.03150, 0.02441, 0.02307, 0.02059]; Within these datasets, each entry corresponds to the same entry as in the prob355, prob532 or prob1064. Basically, what I'm looking for is to compare each of the overall datasets (whilst taking the standard deviation in each value into account) amongst each other and determine if overall these datasets are statistically different from each other. Or if possible I would like to find out which of the values are significantly different from each other. The goal of this comparison for the overall datasets would be prove the hypothesis that these values are not significantly different from one another (prob355 = prob532 = prob1064) or fail to prove the oposite. Secondly, the goal would be to determine if for each of the individual conditions (eg. prob355(1) = prob532(1) = prob1064(1)) the values are significantly different or not. Currently, I'm using Matlab to run my analysis but I'm not bound to this software to run this analysis as long as the alternative is open acces :) So, If anyone knows a good way of making this comparison I would be very happy to hear it. Thanks!

I'm currently facing some issue in determining what statistical test might be best to adopt to determine whether or not my three datasets are significantly different from each other. I have the following datasets of probabilities observed within my Experiment: prob355 = [0.06672, 0.07473, 0.14813, 0.25516]; prob532 = [0.07226, 0.08718, 0.09631, 0.14276]; prob1064 = [0.05979, 0.09020, 0.10891, 0.11307]; Within these datasets, each entry corresponds to a probability obtained under certain experimental conditions such that within the dataset the conditions for prob355(1) ≠ prob355(2) prob355(3) ≠ prob355(4). Between the datasets they have been ordered such that prob355(1) = prob532(1) = prob1064(1). These datasets are accompanied by the following errors/standarddeviation/noise in the observed probabilities: model_error_355 = [0.03255, 0.03986, 0.01321, 0.01928]; model_error_532 = [0.01370, 0.00880, 0.00856, 0.04257]; model_error_1064 = [0.03150, 0.02441, 0.02307, 0.02059]; Within these datasets, each entry corresponds to the same entry as in the prob355, prob532 or prob1064. Basically, what I'm looking for is to compare each of the overall datasets (whilst taking the standard deviation in each value into account) amongst each other and determine if overall these datasets are statistically different from each other. Or if possible I would like to find out which of the values are significantly different from each other. The goal of this comparison for the overall datasets would be prove the hypothesis that these values are not significantly different from one another. Secondly, the goal would be to determine if for each of the individual conditions (eg. prob355(1) = prob532(1) = prob1064(1)) the values are significantly different or not. Currently, I'm using Matlab to run my analysis but I'm not bound to this software to run this analysis as long as the alternative is open acces :) So, If anyone knows a good way of making this comparison I would be very happy to hear it. Thanks!


I have a population who I separated into three groups: low, medium, high exposure. I calculated the standard mortality ratios  for each of this group using a standard population. One of my mentors asked me to do some type of statistical test comparing SMRs in the low versus medium, and low versus high exposure categories. Does anyone know what type of test I can do? Is this even possible? Is there a test for rate ratios?

I have a data set with individuals with a certain diagnosis who are observed from the time of their diagnosis until death or the end date of the study. I want to calculate SMR for the whole group, and also compare subgroups (especially sex and year). My question  regards whether the methodology I describe is sound, and I'd be happy if someone could provide some references (articles or books) where I can read about this specific methodology.  The data is standardised with census data and here are the first six (of 384) rows of data:  year sex   age_group  observed_deaths  expected_deaths 2006   0       15-19                0          0.01480 2006   0       20-24                0          0.05848 2006   0       25-29                3          0.04836 2006   0       30-34                1          0.03835 2006   0       35-39                0          0.06424 2006   0       40-44                2          0.11880   Expected deaths are calculated from the census number of deaths in each year/sex/age group stratum and the person-years of observation time in each stratum.  So the basic method to calculate SMR is to divide the sum of observed deaths (O) with the sum of expected deaths (E). O/E in this case (for the full data set) is 8.68. The standard error is, to my understanding by dividing the square root of O by E, so the confidence intervals using this method are 8.19-9.18. Calculating SMR for each sex is simply done by summing observed and expected deaths for each sex separately, and performing these calculations with each pair of O and E.  So far so good, but I'd like to assess whether there is a difference between sexes as well as a difference between different years of study. If my understanding is correct, this could be done using Poisson regression. So if I start by calculating the basic SMR without taking sex or year into account:  glm(observed_deaths ~ offset(log(expected_deaths)), data=data)   This gives the same SMR at 8.68, but slightly different confidence intervals at 8.20-9.19. Calculating SMRs for each sex is easily done:  glm(observed_deaths[sex==0] ~ offset(log(expected_deaths[sex==0])), data=data) glm(observed_deaths[sex==1] ~ offset(log(expected_deaths[sex==1])), data=data)   And now, I haven't read about this but it seems like I could just add sex as a covariate and get a statistical test for the difference in SMR between the sexes:  glm(observed_deaths ~ offset(log(expected_deaths)) + sex, data=data)   Or if I want to assess a linear effect of time on the log SMR:  glm(observed_deaths ~ offset(log(expected_deaths)) + year, data=data)   Is this methodology sound and valid? I understand that this operates on the assumption that the SMR is the same in all strata not included in the regression model, but that assumption must reasonably be implicit in the simple method (without the use of Poisson regression) as well?  Can anyone point me to some useful references where I can read more about the use of Poisson regression models when calculating SMRs?


The xcolor package influences the spacing of the algebraic sign. How to prevent this behavior?  Screenshot    Mathematical background  The second example should be treated as a binary operator instead of an unary operator.  See:   MWE  \documentclass{scrreprt}  \usepackage{xcolor}  \begin{document} \(1 + 2\)  \(1 {\color{gray} + 2}\)  \end{document}   Workaround  By manually adjusting the spacing...  \(1 {\color{gray}\,+\,2}\)

One can use the command such as \textcolor[rgb]{1.00,0.00,0.00}{boundary} to color the word "boundary" in a document.   Here is my question:  How to color the math symbols in $$? For example, can one turn $C^{2}$ into red in LaTeX?


I am new to Ubuntu and I am trying to update Ubuntu via command line .  So, there is an error occur I don't know how to figure it out. I am using Ubuntu version 15.04 [Vivid Vervet]   sudo apt-get update E: Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) E: Unable to lock directory /var/lib/apt/lists/ E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)  E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?

I get this error when trying to use apt-get:  E: Could not get lock /var/lib/dpkg/lock - open (11 Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?     How can I fix this?


Currently I have Ubuntu MATE 14.04 installed on my system. I have a Windows setup file of Counter Strike 1.6. I have installed WINE from Ubuntu Software Centre. Counter Strike 1.6 has been successfully installed on my system through WINE but when I am about to run it, it does not run, though it has been installed. Can anyone help me in fixing it?

I wish to install Counter Strike 1.6 on Ubuntu 12.04 under wine, but I don't know where to get the source (I have an exe setup file) or how to run it under wine. I will connect to international servers using IP.  Please, give me step by step instructions on where to download the source and how to run it under wine. I'm fairly new to Linux.   Thanks in advance for your help!


Why do we switch the denominator and numerator when we divide fractions?  I've been trying to find out why and I've asked several people and checked many websites but none that give me a good answer. Help?

I have looked up various sites online. They only explain it in a very basic arithmetic way. Would someone explain to me why is $\displaystyle\frac{x}{\frac{1}{2}}$ is $\displaystyle\frac{2x}{1}$?


If $x=\cot6^\circ\cot42^\circ$ and $y=\tan66^\circ\tan78^\circ$, then A) $2x=y$ B) $x=2y$ C) $x=y$ D) $2x=3y$  I seriously don’t know where to start. I don’t need the complete answer, but a starting statement which would give me the direction to solve it would be helpful. Thanks a lot.

My trigonometric problem is:     If $A = \tan6^{\circ} \tan42^{\circ}$ B = cot$66^{\circ} \cot78^{\circ}$ find the relation between $A$ and $B$.    Working :   $$B = \cot 66^{\circ} \cot78^{\circ} = 1- \frac{\tan24^{\circ}+\tan18^{\circ}}{\tan42^{\circ}}$$  $$A= \tan6^{\circ} \tan42^{\circ} = 1- \frac{\tan6^{\circ} +\tan42^{\circ}}{\tan48^{\circ}}$$  but it seems  this is the wrong way of doing this...please suggest. Thanks!


I am attempting to convert a USGS georeferenced pdf to a tiff.  I found this help page, which looks pretty simple:    Except my Conversion Tools do not have "From PDF" (I am running Arcmap 10.2.2).    Does anyone have advice on how to troubleshoot or use another method?

I receive a lot of PDF maps (vector, image, with georeference and without) and I am having to convert them to an image file before I can add them to ArcMap and georeference.    I can't see any obvious out-of-the-box utility that would allow me to add and georeference a PDF directly without having to convert to an image file first.   Any ideas?  I would prefer to add a PDF to map directly without any prior "pdf to image" conversion


I followed a tutorial  about installing phpMyAdmin on Amazon Linux. The step is basically downloading the whole package and extracting the sources to another directory. However, one thing that I don't quite understand is, how is the config file located at /etc/phpMyAdmin/config.inc.php and /etc/httpd/conf.d/phpMyAdmin.conf generated?

I've installed phpmyadmin sudo apt-get install phpmyadmin. Of course, I have also mysql and a web server running properly.  Now how can I reach it?


Sorry if this problem is repeated.  Is there a nonempty perfect set in $\mathbb{R}^1$ which contains no rational number?  Proof sketch: This set must be uncountable because any nonempty perfect set in $\mathbb{R}^k$ is uncountable.   We know that Cantor set (C) is perfect set on a line. If we take $E=C+\sqrt{2}=\{x+\sqrt{2}: x\in C\}$. Will this set be an answer to above problem?

Give an example of a perfect set in $\mathbb R^n$ that does not contain any of the rationals.  (Or prove that it does not exist).


We ought to be bringing down that Close Vote review count down, and performing all other review duties through the mobile application.  I am extremely happy with the mobile application with the single issue that, on my phone, I cannot be doing my duty to review First Posts, Late Answers, Low Quality Posts, Suggested Edits, and soon Reopen Votes and Close Votes ( once I reach 3k reputation in 5+ days [ heh ] ).  What prevents this? Performing review operations from the mobile application is critical.  I know it is a slightly involved activity, but most of us have pretty hefty gadgets with multiple tabs possible, and plenty of ability to perform fully, no matter where we are. We can all be spending plenty of our down time decompressing, by performing our duties... even without getting in trouble for being at our desks and in our labs too long. I say we keep peace in our homes, and bring in this feature set.    I waded through the possible duplicates to this question and have not found any. Do flag if I am wrong. I use the Android version. I am guessing the iOS version also needs this functionality but am not sure.

I know there are some similar posts on adding review queues to the mobile web page. However, this is regarding the Stack Exchange Android app. I really would like to review posts and edits from the Android app, however this isn't included in the app yet. I'm not sure how it would be implemented; maybe there could be a button or something for review. Could we please see this?


Onclick not working in my jquery  I created dynamic div based on select if i click that dynamic div alert is not working  I don't know what is the problem   Date : <input name="startDate" id="startDate" class="date-picker" />

      if i click datediv alert not working> I dont know is problem

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.


Q> In how many ways can 5 identical red beads, 3 identical green beads and 2 identical blue beads be arranged in a necklace?

Six identical yellow balls and four identical red balls are to be arranged in the circumference of a circle.  In how many ways it can be done?


Please help me with this limit without using L'Hôpital's rule. I would by happy if you use simple solving. Thank you as much as I can ;).  $ \lim\limits_{x \to - \infty } {{|\arcsin ({2 \over x})|} \over {\arctan ({5 \over x})}} $

I don't know how to start evaluate this limit, I cannot use L Hopital's rule. Thank you very much for all responses.  $$\mathop {\lim }\limits_{x \to  + \infty } \left({{\arctan \left({4 \over x}\right)} \over {\left|\arcsin \left( - {3 \over x}\right)\right|}}\right)$$


I have a site screen shot(like this - ), and i want to rotate it to "perspective view" like the below image.     How i can do that? Google hinted nothing about this problem.

I'm trying to achieve the effect shown below, but with a photograph and I'm having some trouble maintaining the height width ratio so the photograph doesn't look too distorted - can anyone offer any tips or tutorials?  Thanks in advance for your help.


Jon Snow took the vow to join the Knight's Watch for the rest of his life...but he has died so that would release him. Since he came back to life he has not retaken the vow.

Let's take take a look at the oath of the Night's Watch from Game of Thrones:  "Night gathers, and now my watch begins. It shall not end until my death. I shall take no wife, hold no lands, father no children. I shall wear no crowns and win no glory. I shall live and die at my post. I am the sword in the darkness. I am the watcher on the walls. I am the shield that guards the realms of men. I pledge my life and honor to the Night's Watch, for this night and all the nights to come." ―The Night's Watch oath  But as of S06E02   Now that Jon Snow has died, his watch has ended.  But apparently he's breathing again.  So how much of this makes sense to still be binding? Is he technically free from his oath now? Does the "until my death" part contradict the "and all the nights to come" part?


Calculate the value of the limit      $$ \lim_{n\rightarrow \infty}\left(\frac{n!}{n^n}\right)^{1/n} $$   Can we solve this without using a Riemann sum method? If so, how?

I'm trying to find  $$\lim_{n\to\infty}\frac{n}{\sqrt[n]{n!}} .$$   I tried couple of methods: Stolz, Squeeze, D'Alambert  Thanks!  Edit: I can't use Stirling.


Ok so I started my starter (no pun intended) a few days ago. I got a recipe that said I should keep it at room temp and feed it once a day with 1/2 cup of any flour (I used whole wheat) and 1/4 cup of water. I live in a place over the sea level, near a mountain and it was a pretty warm weather when I started.  So this is what I did:  Day 1: 1 cup flour, 1/2 cup of water, got a thick consistency. Leave it on top of the fridge. Day 2: I see some bubbles on the bottom, get rid of half the mix and feed. Day 3: I see a few bubbles on the top, a lot of bubbles on the bottom and it rise a considerable amount. I get rid of half, feed and keep on with my day. Day 4: It did not rise or have as much bubbles as before. The weather changed a bit, not as hot but still warm. Still got rid of half and feed. Day 5: No change whatsoever, still some bubbles on the bottom but nothing on the top nor it rise. The weather changed, today it's cold and raining.   Everyday it got a vinegary smell which I read is supposed to happen.   I feel like my dough predicted the weather haha. Anyway, what should I do now? Do I keep on feeding it? How long until I know that it didn't work and should start a new one?

I've been trying to grow my own sourdough starter; I went with a 'pure' method, with 50g each of hard-wheat flour from a local mill and water.  I've fed it once and it seems to be bubbling nicely after a couple of days, and the taste is nice and tangy, but I'm not noticing the increase in volume that I would expect.  The area I'm in (the Pacific NW) is still fairly cold (the interior temp in my house is probably mid- to upper-60s) so I suspect that could be a factor, but at what point (I'm about 4 days in now, including a second divide-and-feed pass a day or two ago) should I start to expect any real vigorous expansion out of the starter?


Is there any word or phrase or idiom that describes a person who takes the pleasure from the misfortunes of others?

One word to denote a person who derives pleasure from another's misfortune?