DaHoC’s gists

DaHoC / Java8Tests.java

Created July 10, 2014 09:59

Java 8 playground

	package de.janhendriks.java8test;

	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.List;
	import java.util.function.Consumer;
	import java.util.function.Function;
	import java.util.function.Predicate;
	import java.util.function.Supplier;
	import java.util.function.UnaryOperator;

DaHoC / Timespan.java

Last active September 24, 2019 14:43

Calculate potential overlap for 2 given timespans with begin and end

	package de.playground.test;

	import java.time.Instant;

	public class TimespanOverlap {

	private Instant begin;
	private Instant end;

	public TimespanOverlap(Instant begin, Instant end) {

DaHoC / SQLInjectionSample.java

Last active July 21, 2022 10:00

Example code demonstrating SQL injection attack and prevention hereof. Requires a database.

	package de.janhendriks;

	import java.io.IOException;
	import java.io.PrintWriter;
	import java.sql.Connection;
	import java.sql.DriverManager;
	import java.sql.ResultSet;
	import java.sql.Statement;

	import javax.servlet.ServletException;

DaHoC / ximage2opencvimage.cpp

Last active July 26, 2018 13:47

Example program showing conversion of an image in the X11 XImage format to the openCV format IplImage (by demonstrating the XImage2OpenCVImage function below). The minimalistic program takes a screenshot of a specified area using XGetImage(...), converts the resulting XImage to IplImage and shows the resulting openCV image until the user presses…

	/**
	* Example program showing conversion of an image in the X11 XImage format to the openCV format IplImage
	* (by demonstrating the XImage2OpenCVImage function below)
	* The minimalistic program takes a screenshot of a specified area using XGetImage(...),
	* converts the resulting XImage to IplImage and shows the resulting openCV image until the user presses a key.
	*
	* Compile with opencv linker flags (`pkg-config --libs opencv`) e.g.
	* $ g++ ximage2opencvimage.cpp -L `pkg-config --libs opencv` -o ximage2opencvimage && ./ximage2opencvimage
	*
	* @File: ximage2opencvimage.cpp

DaHoC / opencv_2class_boosting_example.cpp

Created September 8, 2015 09:56

Simple demo program showing how to use boosting in openCV

	/*
	* Simple demo program showing how to use boosted training in openCV
	* File: opencv_2class_boosting_example.cpp
	* Author: Jan Hendriks, [email protected], http://www.janhendriks.de
	*
	* Created on 18. August 2011, 13:55
	*/

	#include <cstdlib>
	#include "opencv/cv.h"

DaHoC / PfPicklistConverter.java

Last active February 15, 2018 12:37

Primefaces Picklist converter

	import org.primefaces.component.picklist.PickList;
	import org.primefaces.model.DualListModel;

	import javax.faces.component.UIComponent;
	import javax.faces.context.FacesContext;
	import javax.faces.convert.Converter;
	import java.util.List;
	import java.util.Objects;

	/**

DaHoC / PfOrderListConverter

Last active February 1, 2017 08:31

	import org.primefaces.component.orderlist.OrderList;

	import javax.faces.component.UIComponent;
	import javax.faces.context.FacesContext;
	import javax.faces.convert.Converter;
	import java.util.List;
	import java.util.Objects;

	/**
	* Generic converter for primefaces component (orderList).

DaHoC / testIpRange.php

Last active December 18, 2018 12:53

IP range check in PHP - This function checks if a given IP address is in a given IP range. It should be much more efficient than the ip2long / long2ip functions that come with PHP that can only be used for IPv4 and have polynomial costs

	<?php
	/*
	> CONTACT:
	Jan Hendriks
	http://www.gawe-design.de
	[email protected]
	> DESCRIPTION:
	The functions (you can also use them via php-include) checks if a given IP is in a given IP range
	These functions are much more efficient than the ip2long / long2ip functions from php that can only be used for IP v4 and have polynomial costs
	These functions are about O(number of positions), e.g. IP v.4: O(4); (I think)

DaHoC / BackpropagationOfError.tex

Created January 21, 2019 08:35

Derivation of "backpropagation of error" formula for a Multi-Layer-Perceptron, written in LaTeX

	\documentclass[10pt, a4paper]{article}

	\usepackage[english,ngerman]{babel}
	\usepackage{amsmath, amssymb, wasysym}
	\usepackage{textcomp}
	\usepackage{graphicx} % Graphics package
	%\usepackage{graphs} % c.f. http://www8.cs.umu.se/~drewes/graphs/
	\usepackage{tikz}
	\usepackage[T1]{fontenc}
	% \usepackage[latin9]{inputenc} % Encoding

DaHoC / JUnitReportTestDurationPieChart.html

Created March 21, 2019 15:01

JUnit test reports (e.g. exported by Eclipse) overview of testsuite durations

	<html>
	<head>
	<title>JUnit Test Report Pie Chart over test durations</title>
	<meta content="">
	<style></style>
	<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
	<script type="text/javascript">
	// Load google charts
	google.charts.load('current', {'packages':['corechart']});
	// google.charts.setOnLoadCallback(drawChart);

Jan Hendriks DaHoC