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Mean per group in a data.frame [duplicate]
... the many ways to specify the variables to act on. Here, vars(-Month) says all variables except Month.
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Can I change a private readonly field in C# using reflection?
...mplementation today does not mean that you can on every implementation for all time. I am not aware of any place where we document that readonly fields must be mutable via reflection. As far as I know, a conforming implementation of the CLI is perfectly free to implement readonly fields such that th...
Fragment in ViewPager using FragmentPagerAdapter is blank the second time it is viewed
...r me too. Here is a link. It seems to save the fragment state, which makes all the difference. developer.android.com/reference/android/support/v4/app/…
– Tjaart
Jan 28 '14 at 12:04
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Declaring an unsigned int in Java
... however, are different. As of Java SE 8, new methods in the Integer class allow you to fully use the int data type to perform unsigned arithmetic:
In Java SE 8 and later, you can use the int data type to represent an unsigned 32-bit integer, which has a minimum value of 0 and a maximum value of...
What is the JSF resource library for and how should it be used?
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Actually, all of those examples on the web wherein the common content/file type like "js", "css", "img", etc is been used as library name are misleading.
Real world examples
To start, let's look at how existing JSF implementati...
Using pre-compiled headers with CMake
...bout hacking together some support for pre-compiled headers in CMake. They all seem a bit all-over the place and everyone has their own way of doing it. What is the best way of doing it currently?
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How unique is UUID?
...om numbers. However, it seems to me that given enough time, it would eventually repeat it self, just by pure chance. Is there a better system or a pattern of some type to alleviate this issue?
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How to find list of possible words from a letter matrix [Boggle Solver]
Lately I have been playing a game on my iPhone called Scramble. Some of you may know this game as Boggle. Essentially, when the game starts you get a matrix of letters like so:
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Create a string of variable length, filled with a repeated character
...slower than a string-concatenation-based implementation. It performs especially badly on large strings. See below for full performance details.
On Firefox, Chrome, Node.js MacOS, Node.js Ubuntu, and Safari, the fastest implementation I tested was:
function repeatChar(count, ch) {
if (count == ...
What is the “FS”/“GS” register intended for?
...dows and Linux.
The original intention behind the segment registers was to allow a program to access many different (large) segments of memory that were intended to be independent and part of a persistent virtual store. The idea was taken from the 1966 Multics operating system, that treated files a...