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How to Copy Contents of One Canvas to Another Canvas Locally

I'd like to copy ALL contents of one canvas and transfer them to another all on the client-side. I would think that I would use the canvas.toDataURL() and context.drawImage() method to implement this but I am running into a few issues. ...
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What does “S3 methods” mean in R?

Since I am fairly new to R, I do not know what the S3 methods and objects are. I found that there are S3 and S4 object systems, and some recommend to use S3 over S4 if possible (See Google's R Style Guide at http://google-styleguide.googlecode.com/svn/trunk/google-r-style.html )*. However, I do not...
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differentiate null=True, blank=True in django

...mines whether the field will be required in forms. This includes the admin and your custom forms. If blank=True then the field will not be required, whereas if it's False the field cannot be blank. The combo of the two is so frequent because typically if you're going to allow a field to be blank in...
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Get current time in milliseconds in Python?

... IMO I'd use floor and not round, but that's just me. If someone asks what the hour is, and it's 7:32, the number they probably want is 7, not 8. – davr Sep 9 '13 at 20:37 ...
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Removing whitespace from strings in Java

... st.replaceAll("\\s+","") removes all whitespaces and non-visible characters (e.g., tab, \n). st.replaceAll("\\s+","") and st.replaceAll("\\s","") produce the same result. The second regex is 20% faster than the first one, but as the number consecutive spaces increases, ...
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Best way to synchronize local HTML5 DB (WebSQL Storage, SQLite) with a server (2 way sync) [closed]

I am developing a mobile web application (for iPhone & Android) with a local database (using html5 webstorage) so my app is still usable when the user is offline. ...
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How do I see a C/C++ source file after preprocessing in Visual Studio?

... cl.exe, the command line interface to Microsoft Visual C++, has three different options for outputting the preprocessed file (hence the inconsistency in the previous responses about Visual C++): /E: preprocess to stdout (similar to GCC's -...
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How do I capture bash output to the Mac OS X clipboard?

... The pbcopy command does this. For example, this puts the output from ls on the clipboard/pasteboard: ls | pbcopy And pbpaste does the reverse, writing to stdout from the clipboard: pbpaste > ls.txt You can use both together to fil...
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Undefined reference to static constexpr char[]

I want to have a static const char array in my class. GCC complained and told me I should use constexpr , although now it's telling me it's an undefined reference. If I make the array a non-member then it compiles. What is going on? ...
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How do I get the time of day in javascript/Node.js?

... This function will return you the date and time in the following format: YYYY:MM:DD:HH:MM:SS. It also works in Node.js. function getDateTime() { var date = new Date(); var hour = date.getHours(); hour = (hour < 10 ? "0" : "") + hour; var min...