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Summarizing multiple columns with dplyr? [duplicate]

... 260 The dplyr package contains summarise_all for this aim: library(dplyr) df %>% group_by(grp) %&...
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PHP - Extracting a property from an array of objects

... 10 Answers 10 Active ...
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How Python web frameworks, WSGI and CGI fit together

... +250 How WSGI, CGI, and the frameworks are all connected? Apache listens on port 80. It gets an HTTP request. It parses the request to f...
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ipython reads wrong python version

...from IPython import start_ipython if __name__ == '__main__': sys.argv[0] = re.sub(r'(-script\.pyw|\.exe)?$', '', sys.argv[0]) sys.exit(start_ipython()) And mine works properly like this, but my situation isn't exactly like the OP's. Original answer -- 9/30/13: cat /usr/local/bin/ipyth...
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Easy way to concatenate two byte arrays

...ghtforward: byte[] c = new byte[a.length + b.length]; System.arraycopy(a, 0, c, 0, a.length); System.arraycopy(b, 0, c, a.length, b.length); share | improve this answer | f...
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What is the meaning of “non temporal” memory accesses in x86

... 150 Non-Temporal SSE instructions (MOVNTI, MOVNTQ, etc.), don't follow the normal cache-coherency ru...
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Having a UITextField in a UITableViewCell

...essoryType = UITableViewCellAccessoryNone; if ([indexPath section] == 0) { UITextField *playerTextField = [[UITextField alloc] initWithFrame:CGRectMake(110, 10, 185, 30)]; playerTextField.adjustsFontSizeToFitWidth = YES; playerTextField.textColor = [UIColor blackColor]; ...
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Performance of static methods vs instance methods

...ethods, can reduce some of the costs discussed at http://joeduffyblog.com/2011/10/23/on-generics-and-some-of-the-associated-overheads/ in the case where that given static isn't called for a given type. As he puts it "As an aside, it turns out that extension methods are a great way to make generic ab...
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Responsive image align center bootstrap 3

...yed on tablets, the product images look ugly because of their small size (500x500) and a width of 767 pixels in the browser. I want to put the image in the center of the screen, but for some reason I can not. Who be will help solve the problem? ...
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Remove file extension from a file name string

... | edited Feb 12 '13 at 0:17 ladenedge 11.7k99 gold badges5454 silver badges102102 bronze badges answe...