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Apply a function to every row of a matrix or a data frame
...function to each row. You pass extra arguments to the function as fourth, fifth, ... arguments to apply().
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Get underlying NSData from UIImage
...ity
or
NSData *imageData = UIImagePNGRepresentation(image);
Depending if you want your data in PNG format or JPG format.
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“static const” vs “#define” vs “enum”
...ar 5
enum { var = 5 };
Ignoring issues about the choice of name, then:
If you need to pass a pointer around, you must use (1).
Since (2) is apparently an option, you don't need to pass pointers around.
Both (1) and (3) have a symbol in the debugger's symbol table - that makes debugging easier. ...
How to check whether a string is Base64 encoded or not
I want to decode a Base64 encoded string, then store it in my database. If the input is not Base64 encoded, I need to throw an error.
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Python: Check if one dictionary is a subset of another larger dictionary
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If the dict values are hashable, using viewitems() is the most optimizied way I can think of: d1.viewitems() <= d2.viewitems(). Timeit runs showed over a 3x performance improvement. If not hashable, even using iteritems(...
How do I get the first element from an IEnumerable in .net?
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If you can use LINQ you can use:
var e = enumerable.First();
This will throw an exception though if enumerable is empty: in which case you can use:
var e = enumerable.FirstOrDefault();
FirstOrDefault() will return defau...
How to handle multiple heterogeneous inputs with Logstash?
Let's say you have 2 very different types of logs such as technical and business logs and you want:
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Function overloading in Javascript - Best practices
...s. This object can hold anything.
function foo(a, b, opts) {
// ...
if (opts['test']) { } //if test param exists, do something..
}
foo(1, 2, {"method":"add"});
foo(3, 4, {"test":"equals", "bar":"tree"});
Then you can handle it anyway you want in your method. [Switch, if-else, etc.]
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How to test if one java class extends another at runtime?
How to I test if a is a subclass of b ?
3 Answers
3
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Array Size (Length) in C#
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If it's a one-dimensional array a,
a.Length
will give the number of elements of a.
If b is a rectangular multi-dimensional array (for example, int[,] b = new int[3, 5];)
b.Rank
will give the number of dimensions (2) an...