Thibault Debatty tdebatty

tdebatty / SumAggregator.java

Created June 9, 2016 07:53

Helper class to perform the sum of a large number of values (sum aggregation).

	import java.util.ArrayList;

	/**
	* Helper class to perform the sum of a large number of values.
	* A double value in java only has 15 significant digits. Hence, when performing
	* the sum of a large number of double values, the precision of the result
	* may be highly altered. For example, if performing the sum of 1E9 values,
	* the result only has 6 significant digits. This helper class performs the
	* addition using groups of 1E5 values. The result has 10 significant digits,
	* for sums of up to 1E10 values.

tdebatty / delete_older_than.php

Last active July 19, 2024 07:42

A simple PHP function to delete files older than a given age. Very handy to rotate backup or log files, for example...

	<?php

	/**
	* A simple function that uses mtime to delete files older than a given age (in seconds)
	* Very handy to rotate backup or log files, for example...
	*
	* $dir String whhere the files are
	* $max_age Int in seconds
	* return String[] the list of deleted files
	*/

tdebatty / NNDescent.php

Last active August 29, 2015 13:56

NN-Descent - A PHP implementation of NN-Descent algorithm : "Efficient k-nearest neighbor graph construction for generic similarity measures"

	<?php
	/* A quick and dirty PHP implemenation of NNDescent algorithm, as proposed in the paper
	* Efficient k-nearest neighbor graph construction for generic similarity measures
	* http://dl.acm.org/citation.cfm?id=1963487
	*
	*/

	/**
	* The algorithm can be used with any kind of item, as long as some
	* similarity metric is defined