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Applying a function to every row of a table using dplyr?
...swer to this problem becomes:
iris %>%
rowwise() %>%
mutate(Max.Len= max(Sepal.Length,Petal.Length))
Non rowwise alternative
Five years (!) later this answer still gets a lot of traffic. Since it was given, rowwise is increasingly not recommended, although lots of people seem to find...
Compare floats in php
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BEWARE! Choosing a fixed epsilon is a bad way just because it looks small, this comparison will return true in alot of precision errors when the numbers are small. A correct way would be to check if the relative error is smaller than the epsilon....
Extract filename and extension in Bash
I want to get the filename (without extension) and the extension separately.
37 Answers
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What exactly is LLVM?
...d as a compiler framework, where you provide the "front end" (parser and lexer) and the "back end" (code that converts LLVM's representation to actual machine code).
LLVM can also act as a JIT compiler - it has support for x86/x86_64 and PPC/PPC64 assembly generation with fast code optimizations ai...
UIImage: Resize, then Crop
...ways set to the full screen size of the device.
@implementation UIImage (Extras)
#pragma mark -
#pragma mark Scale and crop image
- (UIImage*)imageByScalingAndCroppingForSize:(CGSize)targetSize
{
UIImage *sourceImage = self;
UIImage *newImage = nil;
CGSize imageSize = sourceImage....
Pro JavaScript programmer interview questions (with answers) [closed]
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Because JavaScript is such a small language, yet with incredible complexity, you should be able to ask relatively basic questions and find out if they are really that good based on their answers. For instance, my standard first question to gauge the rest of the interview is:
In JavaScript, ...
How to open emacs inside bash
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Just type emacs -nw. This won't open an X window.
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TypeScript Objects as Dictionary types as in C#
I have some JavaScript code that uses objects as dictionaries; for example a 'person' object will hold a some personal details keyed off the email address.
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Should I use a data.frame or a matrix?
When should one use a data.frame , and when is it better to use a matrix ?
6 Answers
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Why can't yield return appear inside a try block with a catch?
...ion is actually an issue that can't be worked around - but the added complexity in the compiler would be very significant.
There are a few things like this that I've already encountered:
Attributes not being able to be generic
Inability for X to derive from X.Y (a nested class in X)
Iterator bloc...