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Mean per group in a data.frame [duplicate]
...
This type of operation is exactly what aggregate was designed for:
d <- read.table(text=
'Name Month Rate1 Rate2
Aira 1 12 23
Aira 2 18 73
Aira 3 19 45
Ben 1 53 19
Ben 2 22 87
Ben 3 ...
Using scanf() in C++ programs is faster than using cin?
...m standard input and XOR all of the numbers.
iostream version:
#include <iostream>
int main(int argc, char **argv) {
int parity = 0;
int x;
while (std::cin >> x)
parity ^= x;
std::cout << parity << std::endl;
return 0;
}
scanf version:
#include <stdi...
CSS text-transform capitalize on all caps
...(this).text(), newVal = '';
val = val.split(' ');
for(var c=0; c < val.length; c++) {
newVal += val[c].substring(0,1).toUpperCase() + val[c].substring(1,val[c].length) + (c+1==val.length ? '' : ' ');
}
$(this).text(newVal);
});
}
$('a.link').ucwords();
...
How to customise file type to syntax associations in Sublime Text?
...
How do you set a default syntax for files opened that have no extension?
– cavalcade
Feb 27 '15 at 23:50
...
Casting a variable using a Type variable
...is an example of a cast and a convert:
using System;
public T CastObject<T>(object input) {
return (T) input;
}
public T ConvertObject<T>(object input) {
return (T) Convert.ChangeType(input, typeof(T));
}
Edit:
Some people in the comments say that this answer doesn't ...
Best way to disable button in Twitter's Bootstrap [duplicate]
I am confused when it comes to disabling a <button> , <input> or an <a> element with classes: .btn or .btn-primary , with JavaScript/jQuery.
...
c++ boost::multi_index composite keys efficiency - c++1y / stl - 清泛IT社区，为创新赋能！
Long time reader first time poster! I'm playing around with the boost::multi_index container stuff and have a rather in-depth question that hopefully a boost or C++ container expert might know (my knowledge in C++ containers is pretty basic). For reference, the boost documentation on composite keys ...
How do I delete unpushed git commits?
...ch the exact branch that you have in the origin.
git reset --hard origin/<branch>
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How to wait for all threads to finish, using ExecutorService?
...you.
ExecutorService taskExecutor = Executors.newFixedThreadPool(4);
List<Callable<?>> tasks; // your tasks
// invokeAll() returns when all tasks are complete
List<Future<?>> futures = taskExecutor.invokeAll(tasks);
...
Convert list to dictionary using linq and not worrying about duplicates
...ng like this:
// Use the first value in list
var _people = new Dictionary<string, Person>(StringComparer.OrdinalIgnoreCase);
foreach (var p in personList)
{
if (!_people.ContainsKey(p.FirstandLastName))
_people[p.FirstandLastName] = p;
}
// Use the last value in list
var _people ...