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Only read selected columns
...g","Sep","Oct","Nov","Dec"))
dat <- fread("data.txt", drop = c(8:13))
All result in:
> data
Year Jan Feb Mar Apr May Jun
1 2009 -41 -27 -25 -31 -31 -39
2 2010 -41 -27 -25 -31 -31 -39
3 2011 -21 -27 -2 -6 -10 -32
UPDATE: When you don't want fread to return a data.table, use the data.ta...
C++11 reverse range-based for-loop
...
Actually Boost does have such adaptor: boost::adaptors::reverse.
#include <list>
#include <iostream>
#include <boost/range/adaptor/reversed.hpp>
int main()
{
std::list<int> x { 2, 3, 5, 7, 11, 13, 1...
How do you convert a DataTable into a generic list?
...e DataTableExtensions.AsEnumerable (an extension method) and then if you really need a List<DataRow> instead of just IEnumerable<DataRow> you can call Enumerable.ToList:
IEnumerable<DataRow> sequence = dt.AsEnumerable();
or
using System.Linq;
...
List<DataRow> list = dt.A...
Remove duplicates from an array of objects in JavaScript
...) dot notation. Yours is ES5 syntax. The others are mostly ES6 (ECMA2015). All are valid in 2017. See jaredwilli's comment.
– agm1984
Nov 15 '17 at 9:20
...
Checking if a double (or float) is NaN in C++
...nly if f is NaN.
Note that, as some comments below have pointed out, not all compilers respect this when optimizing code.
For any compiler which claims to use IEEE floating point, this trick should work. But I can't guarantee that it will work in practice. Check with your compiler, if in doubt.
...
Why does Google +1 record my mouse movements? [closed]
...n't they just use window.crypto.getRandomValues: (function(){var buf = new Uint8Array(1); window.crypto.getRandomValues(buf); alert(buf[0]) } )()
– Rich Bradshaw
Jul 24 '11 at 7:24
...
Is it possible to set private property via reflection?
...lic, you apparently don't need to use BindingFlags.NonPublic to find it. Calling SetValue despite the the setter having less accessibility still does what you expect.
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...
Combining two expressions (Expression)
...m);
}
Starting from .NET 4.0, there is the ExpressionVisitor class which allows you to build expressions that are EF safe.
public static Expression<Func<T, bool>> AndAlso<T>(
this Expression<Func<T, bool>> expr1,
Expression<Func<T, bool>&...
python pandas remove duplicate columns
...he given example, the returned value would be [False,False,True].
Pandas allows one to index using boolean values whereby it selects only the True values. Since we want to keep the unduplicated columns, we need the above boolean array to be flipped (ie [True, True, False] = ~[False,False,True])
F...
How to return result of a SELECT inside a function in PostgreSQL?
... -- potential ambiguity
END
$func$ LANGUAGE plpgsql;
Call:
SELECT * FROM word_frequency(123);
Explanation:
It is much more practical to explicitly define the return type than simply declaring it as record. This way you don't have to provide a column definition list with eve...