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How do I use extern to share variables between source files?
I know that global variables in C sometimes have the extern keyword. What is an extern variable? What is the declaration like? What is its scope?
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Fastest way to replace NAs in a large data.table
I have a large data.table , with many missing values scattered throughout its ~200k rows and 200 columns. I would like to re code those NA values to zeros as efficiently as possible.
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How do I pass a variable by reference?
The Python documentation seems unclear about whether parameters are passed by reference or value, and the following code produces the unchanged value 'Original'
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Is this object-lifetime-extending-closure a C# compiler bug?
I was answering a question about the possibility of closures (legitimately) extending object-lifetimes when I ran into some extremely curious code-gen on the part of the C# compiler (4.0 if that matters).
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Evaluating a mathematical expression in a string
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Pyparsing can be used to parse mathematical expressions. In particular, fourFn.py
shows how to parse basic arithmetic expressions. Below, I've rewrapped fourFn into a numeric parser class for easier reuse.
from __future__ import division...
How to get maximum value from the Collection (for example ArrayList)?
...rrayList stored values are : 10, 20, 30, 40, 50 and the max
value would be 50 .
15 Answers
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Define a lambda expression that raises an Exception
How can I write a lambda expression that's equivalent to:
6 Answers
6
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Is MATLAB OOP slow or am I doing something wrong?
I'm experimenting with MATLAB OOP , as a start I mimicked my C++'s Logger classes and I'm putting all my string helper functions in a String class, thinking it would be great to be able to do things like a + b , a == b , a.find( b ) instead
of strcat( a b ) , strcmp( a, b ) , retrieve first...
Get list of a class' instance methods
...) # => ["new"]
Or you can call methods (not instance_methods) on the object:
test_object = TestClass.new
test_object.methods.grep(/method1/) # => ["method1"]
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What's the difference between ES6 Map and WeakMap?
Looking this and this MDN pages it seems like the only difference between Maps and WeakMaps is a missing "size" property for WeakMaps. But is this true? What's the difference between them?
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