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Hadoop “Unable to load native-hadoop library for your platform” warning
...entOS. The reason you saw that warning is the native Hadoop library $HADOOP_HOME/lib/native/libhadoop.so.1.0.0 was actually compiled on 32 bit.
Anyway, it's just a warning, and won't impact Hadoop's functionalities.
Here is the way if you do want to eliminate this warning, download the source cod...
Generate random numbers using C++11 random library
...lude <random>
#include <iostream>
int main() {
std::random_device rd;
std::mt19937 mt(rd());
std::uniform_real_distribution<double> dist(1.0, 10.0);
for (int i=0; i<16; ++i)
std::cout << dist(mt) << "\n";
}
We use random_device once to see...
Geometric Mean: is there a built-in?
...gth(x) is necessary for the cases where x contains non-positive values.
gm_mean = function(x, na.rm=TRUE){
exp(sum(log(x[x > 0]), na.rm=na.rm) / length(x))
}
Thanks to @ben-bolker for noting the na.rm pass-through and @Gregor for making sure it works correctly.
I think some of the comments ...
Mongodb Explain for Aggregation framework
...erations
explain:true
db.collection.aggregate([
{ $project : { "Tags._id" : 1 }},
{ $unwind : "$Tags" },
{ $match: {$or: [{"Tags._id":"tag1"},{"Tags._id":"tag2"}]}},
{ $group: {
_id : "$_id",
count: { $sum:1 }
}},
{$sort: {"count":-1}}
],
{
explain...
Unique Constraint in Entity Framework Code First
...
CreateIndex("TableName", new string[2] { "Column1", "Column2" }, true, "IX_UniqueColumn1AndColumn2");
Something like that:
namespace Sample.Migrations
{
using System;
using System.Data.Entity.Migrations;
public partial class TableName_SetUniqueCompositeIndex : DbMigration
{
...
CGContextDrawImage draws image upside down when passed UIImage.CGImage
...ingPrintingiOS/GraphicsDrawingOverview/GraphicsDrawingOverview.html#//apple_ref/doc/uid/TP40010156-CH14-SW4
Flipping the Default Coordinate System
Flipping in UIKit drawing modifies the backing CALayer to align a drawing environment having a LLO coordinate system with the default coordinate...
Renaming a virtualenv folder without breaking it
...e
use relative paths, and will change
all the scripts to use
activate_this.py instead of using the
location of the Python interpreter to
select the environment.
Note: you must run this after you've
installed any packages into the
environment. If you make an
environment relocatab...
Group by multiple columns in dplyr, using string vector input
...
Since this question was posted, dplyr added scoped versions of group_by (documentation here). This lets you use the same functions you would use with select, like so:
data = data.frame(
asihckhdoydkhxiydfgfTgdsx = sample(LETTERS[1:3], 100, replace=TRUE),
a30mvxigxkghc5cdsvxvyv0ja = s...
Convert.ChangeType() fails on Nullable Types
...a series of blog posts including this at http://www.endswithsaurus.com/2010_07_01_archive.html (Scroll down to the Addendum, @JohnMacintyre actually spotted the bug in my original code which led me down the same path you're on now). I have a couple of small modifications since that post that includ...
What does the 'b' character do in front of a string literal?
...
Actually, if you've imported unicode_literals from __future__, this will "reverse" the behavior for this particular string (in Python 2.x)
– Romuald Brunet
Mar 14 '13 at 16:27
...