From 77ba4acaae920b651f52b278aad0962d5d981ba1 Mon Sep 17 00:00:00 2001
From: Robert Sesek <rsesek@bluestatic.org>
Date: Fri, 16 Feb 2007 22:50:30 +0000
Subject: [PATCH] Adding the beginnings of the GraphLine system

---
 GraphLine.php | 234 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 234 insertions(+)
 create mode 100644 GraphLine.php

diff --git a/GraphLine.php b/GraphLine.php
new file mode 100644
index 0000000..466f235
--- /dev/null
+++ b/GraphLine.php
@@ -0,0 +1,234 @@
+<?php
+/*=====================================================================*
+|| ###################################################################
+|| # Blue Static ISSO Framework
+|| # Copyright ©2002-[#]year[#] Blue Static
+|| #
+|| # This program is free software; you can redistribute it and/or modify
+|| # it under the terms of the GNU General Public License as published by
+|| # the Free Software Foundation; version [#]gpl[#] of the License.
+|| #
+|| # This program is distributed in the hope that it will be useful, but
+|| # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+|| # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+|| # more details.
+|| #
+|| # You should have received a copy of the GNU General Public License along
+|| # with this program; if not, write to the Free Software Foundation, Inc.,
+|| # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+|| ###################################################################
+\*=====================================================================*/
+
+/**
+* Graphing System: Line Graph (GraphLine.php)
+*
+* @package	ISSO
+*/
+
+require_once('ISSO/Graph.php');
+
+/**
+* Graphing System: Line Graph
+*
+* This creates a line graph from a set of data; each point requires
+* a line name (because this supports multi-line graphing), an x-value,
+* and a y-value. It creates PNG images.
+*
+* @author		Blue Static
+* @copyright	Copyright (c)2002 - [#]year[#], Blue Static
+* @version		$Revision$
+* @package		ISSO
+*
+*/
+class BSGraphLine extends BSGraph
+{
+	/**
+	* Graphing dataset; 4D array
+	* array(array(name, array(array(xval, yval))), color)
+	* @var string
+	*/
+	protected $dataset = array();
+	
+	/**
+	* Array of data points that are used to calculate the standard deviation
+	* @var array
+	*/
+	private $piles = array(0 => array(), 1 => array());
+	
+	// ###################################################################
+	/**
+	* Does the actual graphing and returns a byte stream of a PNG image
+	*
+	* @return	string	Byte stream
+	*/
+	public function graph()
+	{
+		// calculates the standard deviation of the two piles to determine the x and y intervals
+		$xint = $this->_standardDeviation($this->piles[0]);
+		$yint = $this->_standardDeviation($this->piles[1]);
+		
+		$xmin = min($this->piles[0]);
+		$xmin = ($xmin - $xint < 0 ? 0 : $xmin - $xint);
+		$xmax = max($this->piles[0]) + $xint;
+		
+		$ymin = min($this->piles[1]);
+		$ymin = ($ymin - $int < 0 ? 0 : $ymin - $yint);
+		$ymax = max($this->piles[1]) + $yint;
+		
+		
+	}
+	
+	// ###################################################################
+	/**
+	* Adds a "line" with a given name and a set of datapoints in the form
+	* array(x, y)
+	*
+	* @param	string	The line's name
+	* @param	array	Array of array(x,y) as data points
+	*/
+	public function addDataSet($name, $points)
+	{
+		$this->_addPoints($points);
+		$this->_sortPoints($points);
+		$this->dataset[] = array($name, $points, $this->_fetchColor());
+	}
+	
+	// ###################################################################
+	/**
+	* This does the same thing as addDataSet(), except the client code
+	* can specify the color in the form of array(R, G, B)
+	*
+	* @param	string	The line's name
+	* @param	array	Array of array(x,y) as data points
+	* @param	array	A color in the form of 3 RGB points
+	*/
+	public function addDataSetColor($name, $points, $color)
+	{
+		$this->_addPoints($points);
+		$this->_sortPoints($points);
+		$this->dataset[] = array($name, $points, imagecolorallocate($this->image, $color[0], $color[1], $color[2]));
+	}
+	
+	// ###################################################################
+	/**
+	* Adds a set of points to the piles and ensures that they are all valid
+	*
+	* @param	array	Points to add
+	*/
+	private function _addPoints($points)
+	{
+		$xpairs = array();
+		foreach ($points AS $point)
+		{
+			if (isset($xpairs["$point[0]"]))
+			{
+				trigger_error('You cannot have more than one of the same x-values for a given data set');
+			}
+			$xpairs["$point[0]"] = $point[0];
+			$this->piles[0][] = $point[0];
+			$this->piles[1][] = $point[1];
+		}
+	}
+	
+	// ###################################################################
+	/**
+	* Sorts an array of points using quick sort so they're in x-increasing
+	* order
+	*
+	* @param	array	Array of points
+	*/
+	private function _sortPoints(&$points)
+	{
+		$this->_quickSortPoints($points, 0, sizeof($points) - 1);
+	}
+	
+	// ###################################################################
+	/**
+	* Quicksort function for sorting function
+	*
+	* @param	array	Array of points
+	* @param	integer	Lower bound
+	* @param	integer	Upper bound
+	*/
+	private function _quickSortPoints(&$points, $low, $high)
+	{
+		if (($high - $low) > 1)
+		{
+			$partition = $this->_partitionPoints($points, $low, $high);
+			$this->_quickSortPoints($points, $low, $partition);
+			$this->_quickSortPoints($points, $partition + 1, $high);
+		}
+	}
+	
+	// ###################################################################
+	/**
+	* Quicksort partitioner: returns the index of the pivot element where
+	* all x-coords on the left side of pivot are less than or equal to
+	* pivot, and all x-coords are higher to the right
+	*
+	* @param	array	Array of points
+	* @param	integer	Lower bound
+	* @param	integer	Upper bound
+	*
+	* @return	integer	Pivot index
+	*/
+	private function _partitionPoints(&$points, $low, $high)
+	{
+		$pivot = $low;
+		for ($unsorted = $low + 1; $unsorted <= $high; $unsorted++)
+		{ 
+			if ($points[$unsorted][0] < $points[$pivot][0])
+			{
+				$temp = $points[$pivot];
+				$points[$pivot] = $points[$unsorted];
+				$points[$unsorted] = $points[$pivot + 1];
+				$points[$pivot + 1] = $temp;
+				$pivot++;
+			}
+		}
+		return $pivot;
+	}
+	
+	// ###################################################################
+	/**
+	* Returns the unbiased statistical standard deviation of an array of
+	* values
+	*
+	* @param	array	Array of values
+	*
+	* @return	float	Standard deviation (unbiased)
+	*/
+	private function _standardDeviation($vals)
+	{
+		$average = $this->_arrayAverage($vals);
+		$popVariance = array();
+		
+		foreach ($vals AS $val)
+		{
+			$popVariance[] = pow($val - $average, 2);
+		}
+		
+		return sqrt($this->_arrayAverage($popVariance));
+	}
+	
+	// ###################################################################
+	/**
+	* Returns the stastical mean of an array of values
+	*
+	* @param	array	Array of values
+	*
+	* @return	float	Statistical mean
+	*/
+	private function _arrayAverage($vals)
+	{
+		return array_sum($vals) / count($vals);
+	}
+}
+
+/*=====================================================================*
+|| ###################################################################
+|| # $HeadURL$
+|| # $Id$
+|| ###################################################################
+\*=====================================================================*/
+?>
\ No newline at end of file
-- 
2.43.5