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Pass a data.frame column name to a function
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edited Apr 11 '16 at 21:42
joran
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User recognition without cookies or local storage
...ficult to get people to install these kinds of programs on their system. This leaves you stuck with using Cookies and other, similar tools.
Cookies and other, similar tools
You might consider building a Data Profile, then using Probability tests to identify a Probable User. A profile useful for th...
Center a DIV horizontally and vertically [duplicate]
Is there a way to CENTER A DIV vertically and horizontally but, and that is important, that the content will not be cut when the window is smaller than the content The div must have a background color and a width and hight.
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Detect Chrome extension first run / update
How can an extension find out that it is being run for the first time or has just been updated, so that the extension can perform some specific actions? (e.g. open a help page or update settings)
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namespaces for enum types - best practices
...ated types together. Sometimes, one has a name clash. Two solutions to this come to mind: use a namespace, or use 'larger' enum element names. Still, the namespace solution has two possible implementations: a dummy class with nested enum, or a full blown namespace.
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Algorithm to return all combinations of k elements from n
... fit your particular situation better than how I describe.
Gray Codes
An issue that you will come across is of course memory and pretty quickly, you'll have problems by 20 elements in your set -- 20C3 = 1140. And if you want to iterate over the set it's best to use a modified gray code algorithm s...
Markdown and image alignment
I am making a site that publishes articles in issues each month. It is straightforward, and I think using a Markdown editor (like the WMD one here in Stack Overflow) would be perfect.
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Subset of rows containing NA (missing) values in a chosen column of a data frame
.... If the date was not recorded, the CSV file contains the value NA , for missing data.
6 Answers
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How to pop an alert message box using PHP?
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You could use Javascript:
// This is in the PHP file and sends a Javascript alert to the client
$message = "wrong answer";
echo "<script type='text/javascript'>alert('$message');</script>";
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Why do you program in assembly? [closed]
...question for all the hardcore low level hackers out there. I ran across this sentence in a blog. I don't really think the source matters (it's Haack if you really care) because it seems to be a common statement.
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