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Replacing NAs with latest non-NA value
In a data.frame (or data.table), I would like to "fill forward" NAs with the closest previous non-NA value. A simple example, using vectors (instead of a data.frame ) is the following:
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How does Java handle integer underflows and overflows and how would you check for it?
How does Java handle integer underflows and overflows?
12 Answers
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What are the most-used vim commands/keypresses?
I'm a Ruby programming trying to switch from Textmate to MacVim, and I'm having trouble wading through the gargantuan lists of things you can do in VIM and all of the keypresses for them. I'm tired of hearing "You can use 'I' for inserting text, or 'a' for appending text after the character, or 'A' ...
How to access the correct `this` inside a callback?
I have a constructor function which registers an event handler:
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How to clone a case class instance and change just one field in Scala?
Let's say I have a case class that represents personas, people on different social networks. Instances of that class are fully immutable, and are held in immutable collections, to be eventually modified by an Akka actor.
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Visual Studio Solutions Folder as real Folders
I have a Visual Studio Solution. Currently, it is an empty solution (=no projects) and I have added a few solution folders.
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Constructor of an abstract class in C#
Why is it possible to write constructor for an abstract class in C#?
As far as I know we can't instantiate an abstract class.. so what is it for?
You can't instantiate the class, right?
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How to check if a string is a valid JSON string in JavaScript without using Try/Catch
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22 Answers
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Changing every value in a hash in Ruby
I want to change every value in a hash so as to add '%' before and after the value so
11 Answers
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How to check whether a script is running under Node.js?
I have a script I am requiring from a Node.js script, which I want to keep JavaScript engine independent.
20 Answers
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