624 lines
No EOL
20 KiB
PHP
624 lines
No EOL
20 KiB
PHP
<?php if ( ! defined( 'ABSPATH' ) ) exit;
|
||
/**
|
||
* Equation Operating System Classes.
|
||
*
|
||
* This class was created for the safe parsing of mathematical equations
|
||
* in PHP. There is a need for a way to successfully parse equations
|
||
* in PHP that do NOT require the use of `eval`. `eval` at its core
|
||
* opens the system using it to so many security vulnerabilities it is oft
|
||
* suggested /never/ to use it, and for good reason. This class set will
|
||
* successfully take an equation, parse it, and provide solutions to the
|
||
* developer. It is a safe way to evaluate expressions without putting
|
||
* the system at risk.
|
||
*
|
||
* 2013/04 UPDATE:
|
||
* - Moved to native class functions for PHP5
|
||
* - Removed deprecated `eregi` calls to `preg_match`
|
||
* - Updated to PHPDoc comment syntax
|
||
* - Added Exception throwing instead of silent exits
|
||
* - Added additional variable prefix of '$', '&' is still allowed as well
|
||
* - Fixed small implied multiplication problem
|
||
*
|
||
* TODO:
|
||
* - Add factorial support. (ie 5! = 120)
|
||
*
|
||
* @author Jon Lawrence <jlawrence11@gmail.com>
|
||
* @copyright Copyright <20>2005-2013, Jon Lawrence
|
||
* @license http://opensource.org/licenses/LGPL-2.1 LGPL 2.1 License
|
||
* @package EOS
|
||
* @version 2.0
|
||
*/
|
||
|
||
//The following are defines for thrown exceptions
|
||
|
||
/**
|
||
* No matching Open/Close pair
|
||
*/
|
||
define('EQEOS_E_NO_SET', 5500);
|
||
/**
|
||
* Division by 0
|
||
*/
|
||
define('EQEOS_E_DIV_ZERO', 5501);
|
||
/**
|
||
* No Equation
|
||
*/
|
||
define('EQEOS_E_NO_EQ', 5502);
|
||
/**
|
||
* No variable replacement available
|
||
*/
|
||
define('EQEOS_E_NO_VAR', 5503);
|
||
|
||
if(!defined('DEBUG'))
|
||
define('DEBUG', false);
|
||
|
||
//We use a stack class so we don't have to keep track of indices for an array
|
||
// May eventually update to use `array_pop()` `end()` and `array_push()` instead
|
||
// of this class.
|
||
require_once "stack.class.php";
|
||
|
||
|
||
/**
|
||
* Equation Operating System (EOS) Parser
|
||
*
|
||
* An EOS that can safely parse equations from unknown sources returning
|
||
* the calculated value of it. Can also handle solving equations with
|
||
* variables, if the variables are defined (useful for the Graph creation
|
||
* that the second and extended class in this file provides. {@see eqGraph})
|
||
* This class was created for PHP4 in 2005, updated to fully PHP5 in 2013.
|
||
*
|
||
* @author Jon Lawrence <jlawrence11@gmail.com>
|
||
* @copyright Copyright <20>2005-2013, Jon Lawrence
|
||
* @license http://opensource.org/licenses/LGPL-2.1 LGPL 2.1 License
|
||
* @package Math
|
||
* @subpackage EOS
|
||
* @version 2.0
|
||
*/
|
||
class eqEOS {
|
||
/**#@+
|
||
*Private variables
|
||
*/
|
||
private $postFix;
|
||
private $inFix;
|
||
/**#@-*/
|
||
/**#@+
|
||
* Protected variables
|
||
*/
|
||
//What are opening and closing selectors
|
||
protected $SEP = array('open' => array('(', '['), 'close' => array(')', ']'));
|
||
//Top presedence following operator - not in use
|
||
protected $SGL = array('!');
|
||
//Order of operations arrays follow
|
||
protected $ST = array('^');
|
||
protected $ST1 = array('/', '*', '%');
|
||
protected $ST2 = array('+', '-');
|
||
//Allowed functions
|
||
protected $FNC = array('sin', 'cos', 'tan', 'csc', 'sec', 'cot');
|
||
/**#@-*/
|
||
/**
|
||
* Construct method
|
||
*
|
||
* Will initiate the class. If variable given, will assign to
|
||
* internal variable to solve with this::solveIF() without needing
|
||
* additional input. Initializing with a variable is not suggested.
|
||
*
|
||
* @see eqEOS::solveIF()
|
||
* @param String $inFix Standard format equation
|
||
*/
|
||
public function __construct($inFix = null) {
|
||
$this->inFix = (isset($inFix)) ? $inFix : null;
|
||
$this->postFix = array();
|
||
}
|
||
|
||
/**
|
||
* Check Infix for opening closing pair matches.
|
||
*
|
||
* This function is meant to solely check to make sure every opening
|
||
* statement has a matching closing one, and throws an exception if
|
||
* it doesn't.
|
||
*
|
||
* @param String $infix Equation to check
|
||
* @throws Exception if malformed.
|
||
* @return Bool true if passes - throws an exception if not.
|
||
*/
|
||
private function checkInfix($infix) {
|
||
if(trim($infix) == "") {
|
||
throw new Exception("No Equation given", EQEOS_E_NO_EQ);
|
||
return false;
|
||
}
|
||
//Make sure we have the same number of '(' as we do ')'
|
||
// and the same # of '[' as we do ']'
|
||
if(substr_count($infix, '(') != substr_count($infix, ')')) {
|
||
throw new Exception("Mismatched parenthesis in '{$infix}'", EQEOS_E_NO_SET);
|
||
return false;
|
||
} elseif(substr_count($infix, '[') != substr_count($infix, ']')) {
|
||
throw new Exception("Mismatched brackets in '{$infix}'", EQEOS_E_NO_SET);
|
||
return false;
|
||
}
|
||
$this->inFix = $infix;
|
||
return true;
|
||
}
|
||
|
||
/**
|
||
* Infix to Postfix
|
||
*
|
||
* Converts an infix (standard) equation to postfix (RPN) notation.
|
||
* Sets the internal variable $this->postFix for the eqEOS::solvePF()
|
||
* function to use.
|
||
*
|
||
* @link http://en.wikipedia.org/wiki/Infix_notation Infix Notation
|
||
* @link http://en.wikipedia.org/wiki/Reverse_Polish_notation Reverse Polish Notation
|
||
* @param String $infix A standard notation equation
|
||
* @return Array Fully formed RPN Stack
|
||
*/
|
||
public function in2post($infix = null) {
|
||
// if an equation was not passed, use the one that was passed in the constructor
|
||
$infix = (isset($infix)) ? $infix : $this->inFix;
|
||
|
||
//check to make sure 'valid' equation
|
||
$this->checkInfix($infix);
|
||
$pf = array();
|
||
$ops = new phpStack();
|
||
$vars = new phpStack();
|
||
|
||
// remove all white-space
|
||
preg_replace("/\s/", "", $infix);
|
||
|
||
// Create postfix array index
|
||
$pfIndex = 0;
|
||
|
||
//what was the last character? (useful for decerning between a sign for negation and subtraction)
|
||
$lChar = '';
|
||
|
||
//loop through all the characters and start doing stuff ^^
|
||
for($i=0;$i<strlen($infix);$i++) {
|
||
// pull out 1 character from the string
|
||
$chr = substr($infix, $i, 1);
|
||
|
||
// if the character is numerical
|
||
if(preg_match('/[0-9.]/i', $chr)) {
|
||
// if the previous character was not a '-' or a number
|
||
if((!preg_match('/[0-9.]/i', $lChar) && ($lChar != "")) && (@$pf[$pfIndex]!="-"))
|
||
$pfIndex++; // increase the index so as not to overlap anything
|
||
// Add the number character to the array
|
||
@$pf[$pfIndex] .= $chr;
|
||
}
|
||
// If the character opens a set e.g. '(' or '['
|
||
elseif(in_array($chr, $this->SEP['open'])) {
|
||
// if the last character was a number, place an assumed '*' on the stack
|
||
if(preg_match('/[0-9.]/i', $lChar))
|
||
$ops->push('*');
|
||
|
||
$ops->push($chr);
|
||
}
|
||
// if the character closes a set e.g. ')' or ']'
|
||
elseif(in_array($chr, $this->SEP['close'])) {
|
||
// find what set it was i.e. matches ')' with '(' or ']' with '['
|
||
$key = array_search($chr, $this->SEP['close']);
|
||
// while the operator on the stack isn't the matching pair...pop it off
|
||
while($ops->peek() != $this->SEP['open'][$key]) {
|
||
$nchr = $ops->pop();
|
||
if($nchr)
|
||
$pf[++$pfIndex] = $nchr;
|
||
else {
|
||
throw new Exception("Error while searching for '". $this->SEP['open'][$key] ."' in '{$infix}'.", EQEOS_E_NO_SET);
|
||
return false;
|
||
}
|
||
}
|
||
$ops->pop();
|
||
}
|
||
// If a special operator that has precedence over everything else
|
||
elseif(in_array($chr, $this->ST)) {
|
||
$ops->push($chr);
|
||
$pfIndex++;
|
||
}
|
||
// Any other operator other than '+' and '-'
|
||
elseif(in_array($chr, $this->ST1)) {
|
||
while(in_array($ops->peek(), $this->ST1) || in_array($ops->peek(), $this->ST))
|
||
$pf[++$pfIndex] = $ops->pop();
|
||
|
||
$ops->push($chr);
|
||
$pfIndex++;
|
||
}
|
||
// if a '+' or '-'
|
||
elseif(in_array($chr, $this->ST2)) {
|
||
// if it is a '-' and the character before it was an operator or nothingness (e.g. it negates a number)
|
||
if((in_array($lChar, array_merge($this->ST1, $this->ST2, $this->ST, $this->SEP['open'])) || $lChar=="") && $chr=="-") {
|
||
// increase the index because there is no reason that it shouldn't..
|
||
$pfIndex++;
|
||
$pf[$pfIndex] = $chr;
|
||
}
|
||
// Otherwise it will function like a normal operator
|
||
else {
|
||
while(in_array($ops->peek(), array_merge($this->ST1, $this->ST2, $this->ST)))
|
||
$pf[++$pfIndex] = $ops->pop();
|
||
$ops->push($chr);
|
||
$pfIndex++;
|
||
}
|
||
}
|
||
// make sure we record this character to be refered to by the next one
|
||
$lChar = $chr;
|
||
}
|
||
// if there is anything on the stack after we are done...add it to the back of the RPN array
|
||
while(($tmp = $ops->pop()) !== false)
|
||
$pf[++$pfIndex] = $tmp;
|
||
|
||
// re-index the array at 0
|
||
$pf = array_values($pf);
|
||
|
||
// set the private variable for later use if needed
|
||
$this->postFix = $pf;
|
||
|
||
// return the RPN array in case developer wants to use it fro some insane reason (bug testing ;]
|
||
return $pf;
|
||
} //end function in2post
|
||
|
||
/**
|
||
* Solve Postfix (RPN)
|
||
*
|
||
* This function will solve a RPN array. Default action is to solve
|
||
* the RPN array stored in the class from eqEOS::in2post(), can take
|
||
* an array input to solve as well, though default action is prefered.
|
||
*
|
||
* @link http://en.wikipedia.org/wiki/Reverse_Polish_notation Postix Notation
|
||
* @param Array $pfArray RPN formatted array. Optional.
|
||
* @return Float Result of the operation.
|
||
*/
|
||
public function solvePF($pfArray = null) {
|
||
// if no RPN array is passed - use the one stored in the private var
|
||
$pf = (!is_array($pfArray)) ? $this->postFix : $pfArray;
|
||
|
||
// create our temporary function variables
|
||
$temp = array();
|
||
$tot = 0;
|
||
$hold = 0;
|
||
|
||
// Loop through each number/operator
|
||
for($i=0;$i<count($pf); $i++) {
|
||
// If the string isn't an operator, add it to the temp var as a holding place
|
||
if(!in_array($pf[$i], array_merge($this->ST, $this->ST1, $this->ST2))) {
|
||
$temp[$hold++] = $pf[$i];
|
||
}
|
||
// ...Otherwise perform the operator on the last two numbers
|
||
else {
|
||
switch ($pf[$i]) {
|
||
case '+':
|
||
@$temp[$hold-2] = $temp[$hold-2] + $temp[$hold-1];
|
||
break;
|
||
case '-':
|
||
@$temp[$hold-2] = $temp[$hold-2] - $temp[$hold-1];
|
||
break;
|
||
case '*':
|
||
@$temp[$hold-2] = $temp[$hold-2] * $temp[$hold-1];
|
||
break;
|
||
case '/':
|
||
if($temp[$hold-1] == 0) {
|
||
throw new Exception("Division by 0 on: '{$temp[$hold-2]} / {$temp[$hold-1]}' in {$this->inFix}", EQEOS_E_DIV_ZERO);
|
||
return false;
|
||
}
|
||
@$temp[$hold-2] = $temp[$hold-2] / $temp[$hold-1];
|
||
break;
|
||
case '^':
|
||
@$temp[$hold-2] = pow($temp[$hold-2], $temp[$hold-1]);
|
||
break;
|
||
case '%':
|
||
if($temp[$hold-1] == 0) {
|
||
throw new Exception("Division by 0 on: '{$temp[$hold-2]} % {$temp[$hold-1]}' in {$this->inFix}", EQEOS_E_DIV_ZERO);
|
||
return false;
|
||
}
|
||
@$temp[$hold-2] = bcmod($temp[$hold-2], $temp[$hold-1]);
|
||
break;
|
||
}
|
||
// Decrease the hold var to one above where the last number is
|
||
$hold = $hold-1;
|
||
}
|
||
}
|
||
// return the last number in the array
|
||
return $temp[$hold-1];
|
||
|
||
} //end function solvePF
|
||
|
||
|
||
/**
|
||
* Solve Infix (Standard) Notation Equation
|
||
*
|
||
* Will take a standard equation with optional variables and solve it. Variables
|
||
* must begin with '&' will expand to allow variables to begin with '$' (TODO)
|
||
* The variable array must be in the format of 'variable' => value. If
|
||
* variable array is scalar (ie 5), all variables will be replaced with it.
|
||
*
|
||
* @param String $infix Standard Equation to solve
|
||
* @param String|Array $vArray Variable replacement
|
||
* @return Float Solved equation
|
||
*/
|
||
function solveIF($infix, $vArray = null) {
|
||
$infix = ($infix != "") ? $infix : $this->inFix;
|
||
|
||
//Check to make sure a 'valid' expression
|
||
$this->checkInfix($infix);
|
||
|
||
$ops = new phpStack();
|
||
$vars = new phpStack();
|
||
|
||
//remove all white-space
|
||
preg_replace("/\s/", "", $infix);
|
||
if(DEBUG)
|
||
$hand=fopen("eq.txt","a");
|
||
|
||
//Find all the variables that were passed and replaces them
|
||
while((preg_match('/(.){0,1}[&$]([a-zA-Z]+)(.){0,1}/', $infix, $match)) != 0) {
|
||
|
||
//remove notices by defining if undefined.
|
||
if(!isset($match[3])) {
|
||
$match[3] = "";
|
||
}
|
||
|
||
if(DEBUG)
|
||
fwrite($hand, "{$match[1]} || {$match[3]}\n");
|
||
// Ensure that the variable has an operator or something of that sort in front and back - if it doesn't, add an implied '*'
|
||
if((!in_array($match[1], array_merge($this->ST, $this->ST1, $this->ST2, $this->SEP['open'])) && $match[1] != "") || is_numeric($match[1])) //$this->SEP['close'] removed
|
||
$front = "*";
|
||
else
|
||
$front = "";
|
||
|
||
if((!in_array($match[3], array_merge($this->ST, $this->ST1, $this->ST2, $this->SEP['close'])) && $match[3] != "") || is_numeric($match[3])) //$this->SEP['open'] removed
|
||
$back = "*";
|
||
else
|
||
$back = "";
|
||
|
||
//Make sure that the variable does have a replacement
|
||
if(!isset($vArray[$match[2]]) && (!is_array($vArray != "") && !is_numeric($vArray))) {
|
||
throw new Exception("Variable replacement does not exist for '". substr($match[0], 1, -1) ."' in {$this->inFix}", EQEOS_E_NO_VAR);
|
||
return false;
|
||
} elseif(!isset($vArray[$match[2]]) && (!is_array($vArray != "") && is_numeric($vArray))) {
|
||
$infix = str_replace($match[0], $match[1] . $front. $vArray. $back . $match[3], $infix);
|
||
} elseif(isset($vArray[$match[2]])) {
|
||
$infix = str_replace($match[0], $match[1] . $front. $vArray[$match[2]]. $back . $match[3], $infix);
|
||
}
|
||
}
|
||
|
||
if(DEBUG)
|
||
fwrite($hand, "$infix\n");
|
||
|
||
// Finds all the 'functions' within the equation and calculates them
|
||
// NOTE - when using function, only 1 set of paranthesis will be found, instead use brackets for sets within functions!!
|
||
while((preg_match("/(". implode("|", $this->FNC) . ")\(([^\)\(]*(\([^\)]*\)[^\(\)]*)*[^\)\(]*)\)/", $infix, $match)) != 0) {
|
||
$func = $this->solveIF($match[2]);
|
||
switch($match[1]) {
|
||
case "cos":
|
||
$ans = cos($func);
|
||
break;
|
||
case "sin":
|
||
$ans = sin($func);
|
||
break;
|
||
case "tan":
|
||
$ans = tan($func);
|
||
break;
|
||
case "sec":
|
||
$tmp = cos($func);
|
||
if($tmp == 0) {
|
||
throw new Exception("Division by 0 on: 'sec({$func}) = 1/cos({$func})' in {$this->inFix}", EQEOS_E_DIV_ZERO);
|
||
return false;
|
||
}
|
||
$ans = 1/$tmp;
|
||
break;
|
||
case "csc":
|
||
$tmp = sin($func);
|
||
if($tmp == 0) {
|
||
throw new Exception("Division by 0 on: 'csc({$func}) = 1/sin({$func})' in {$this->inFix}", EQEOS_E_DIV_ZERO);
|
||
return false;
|
||
}
|
||
$ans = 1/$tmp;
|
||
break;
|
||
case "cot":
|
||
$tmp = tan($func);
|
||
if($tmp == 0) {
|
||
throw new Exception("Division by 0 on: 'cot({$func}) = 1/tan({$func})' in {$this->inFix}", EQEOS_E_DIV_ZERO);
|
||
return false;
|
||
}
|
||
$ans = 1/$tmp;
|
||
break;
|
||
default:
|
||
break;
|
||
}
|
||
$infix = str_replace($match[0], $ans, $infix);
|
||
}
|
||
if(DEBUG)
|
||
fclose($hand);
|
||
return $this->solvePF($this->in2post($infix));
|
||
|
||
|
||
} //end function solveIF
|
||
} //end class 'eqEOS'
|
||
|
||
|
||
// fun class that requires the GD libraries to give visual output to the user
|
||
/* extends the eqEOS class so that it doesn't need to create it as a private var
|
||
- and it extends the functionality of that class */
|
||
/**
|
||
* Equation Graph
|
||
*
|
||
* Fun class that requires the GD libraries to give visual output of an
|
||
* equation to the user. Extends the eqEOS class.
|
||
*
|
||
* @author Jon Lawrence <jlawrence11@gmail.com>
|
||
* @copyright Copyright <20>2005-2013 Jon Lawrence
|
||
* @license http://opensource.org/licenses/LGPL-2.1 LGPL 2.1 License
|
||
* @package Math
|
||
* @subpackage EOS
|
||
* @version 2.0
|
||
*/
|
||
class eqGraph extends eqEOS {
|
||
private $width;
|
||
private $height;
|
||
//GD Image reference
|
||
private $image;
|
||
|
||
/**
|
||
* Constructor
|
||
*
|
||
* Sets up the Graph class with an image width and height defaults to
|
||
* 640x480
|
||
*
|
||
* @param Integer $width Image width
|
||
* @param Integer $height Image height
|
||
*/
|
||
public function __construct($width=640, $height=480) {
|
||
// default width and height equal to that of a poor monitor (in early 2000s)
|
||
$this->width = $width;
|
||
$this->height = $height;
|
||
//initialize main class variables
|
||
parent::__construct();
|
||
} //end function eqGraph
|
||
|
||
|
||
/**
|
||
* Create GD Graph Image
|
||
*
|
||
* Creates a GD image based on the equation given with the parameters that are set
|
||
*
|
||
* @param String $eq Equation to use. Needs variable in equation to create graph, all variables are interpreted as 'x'
|
||
* @param Integer $xLow Lower x-bound for graph
|
||
* @param Integer $xHigh Upper x-bound for graph
|
||
* @param Float $xStep Stepping points while solving, the lower, the better precision. Slow if lower than .01
|
||
* @param Boolean $xyGrid Draw gridlines?
|
||
* @param Boolean $yGuess Guess the upper/lower yBounds?
|
||
* @param Integer $yLow Lower y-bound
|
||
* @param Integer $yHigh Upper y-bound
|
||
* @return Null
|
||
*/
|
||
public function graph($eq, $xLow, $xHigh, $xStep, $xyGrid = false, $yGuess = true, $yLow=false, $yHigh=false) {
|
||
//create our image and allocate the two colors
|
||
$img = ImageCreate($this->width, $this->height);
|
||
$white = ImageColorAllocate($img, 255, 255, 255);
|
||
$black = ImageColorAllocate($img, 0, 0, 0);
|
||
$grey = ImageColorAllocate($img, 220, 220, 220);
|
||
$xStep = abs($xStep);
|
||
//DEVELOPER, UNCOMMENT NEXT LINE IF WANTING TO PREVENT SLOW GRAPHS
|
||
//$xStep = ($xStep > .01) ? $xStep : 0.01;
|
||
if($xLow > $xHigh)
|
||
list($xLow, $xHigh) = array($xHigh, $xLow); //swap function
|
||
|
||
$xScale = $this->width/($xHigh-$xLow);
|
||
$counter = 0;
|
||
if(DEBUG) {
|
||
$hand=fopen("eqgraph.txt","w");
|
||
fwrite($hand, "$eq\n");
|
||
}
|
||
for($i=$xLow;$i<=$xHigh;$i+=$xStep) {
|
||
$tester = sprintf("%10.3f",$i);
|
||
if($tester == "-0.000") $i = 0;
|
||
$y = $this->solveIF($eq, $i);
|
||
//eval('$y='. str_replace('&x', $i, $eq).";"); /* used to debug my eqEOS class results */
|
||
if(DEBUG) {
|
||
$tmp1 = sprintf("y(%5.3f) = %10.3f\n", $i, $y);
|
||
fwrite($hand, $tmp1);
|
||
}
|
||
|
||
// If developer asked us to find the upper and lower bounds for y...
|
||
if($yGuess==true) {
|
||
$yLow = ($yLow===false || ($y<$yLow)) ? $y : $yLow;
|
||
$yHigh = ($yHigh===false || $y>$yHigh) ? $y : $yHigh;
|
||
}
|
||
$xVars[$counter] = $y;
|
||
$counter++;
|
||
}
|
||
if(DEBUG)
|
||
fclose($hand);
|
||
// add 0.01 to each side so that if y is from 1 to 5, the lines at 1 and 5 are seen
|
||
$yLow-=0.01;$yHigh+=0.01;
|
||
|
||
//Now that we have all the variables stored...find the yScale
|
||
$yScale = $this->height/(($yHigh)-($yLow));
|
||
|
||
// if developer wanted a grid on the graph, add it now
|
||
if($xyGrid==true) {
|
||
for($i=ceil($yLow);$i<=floor($yHigh);$i++) {
|
||
$i0 = abs($yHigh-$i);
|
||
ImageLine($img, 0, $i0*$yScale, $this->width, $i0*$yScale, $grey);
|
||
}
|
||
for($i=ceil($xLow);$i<=floor($xHigh);$i++) {
|
||
$i0 = abs($xLow-$i);
|
||
ImageLine($img, $i0*$xScale, 0, $i0*$xScale, $this->height, $grey);
|
||
}
|
||
}
|
||
|
||
//Now that we have the scales, let's see if we can draw an x/y-axis
|
||
if($xLow <= 0 && $xHigh >= 0) {
|
||
//the y-axis is within our range - draw it.
|
||
$x0 = abs($xLow)*$xScale;
|
||
ImageLine($img, $x0, 0, $x0, $this->height, $black);
|
||
for($i=ceil($yLow);$i<=floor($yHigh);$i++) {
|
||
$i0 = abs($yHigh-$i);
|
||
ImageLine($img, $x0-3, $i0*$yScale, $x0+3, $i0*$yScale, $black);
|
||
}
|
||
}
|
||
if($yLow <= 0 && $yHigh >= 0) {
|
||
//the x-axis is within our range - draw it.
|
||
$y0 = abs($yHigh)*$yScale;
|
||
ImageLine($img, 0, $y0, $this->width, $y0, $black);
|
||
for($i=ceil($xLow);$i<=floor($xHigh);$i++) {
|
||
$i0 = abs($xLow-$i);
|
||
ImageLine($img, $i0*$xScale, $y0-3, $i0*$xScale, $y0+3, $black);
|
||
}
|
||
}
|
||
$counter=2;
|
||
|
||
//now graph it all ;]
|
||
for($i=$xLow+$xStep;$i<=$xHigh;$i+=$xStep) {
|
||
$x1 = (abs($xLow - ($i - $xStep)))*$xScale;
|
||
$y1 = (($xVars[$counter-1]<$yLow) || ($xVars[$counter-1] > $yHigh)) ? -1 : (abs($yHigh - $xVars[$counter-1]))*$yScale;
|
||
$x2 = (abs($xLow - $i))*$xScale;
|
||
$y2 = (($xVars[$counter]<$yLow) || ($xVars[$counter] > $yHigh)) ? -1 : (abs($yHigh - $xVars[$counter]))*$yScale;
|
||
|
||
// if any of the y values were found to be off of the y-bounds, don't graph those connecting lines
|
||
if($y1!=-1 && $y2!=-1)
|
||
ImageLine($img, $x1, $y1, $x2, $y2, $black);
|
||
$counter++;
|
||
}
|
||
$this->image = $img;
|
||
} //end function 'graph'
|
||
|
||
/**
|
||
* Sends JPG to browser
|
||
*
|
||
* Sends a JPG image with proper header to output
|
||
*/
|
||
public function outJPG() {
|
||
header("Content-type: image/jpeg");
|
||
ImageJpeg($this->image);
|
||
}
|
||
|
||
/**
|
||
* Sends PNG to browser
|
||
*
|
||
* Sends a PNG image with proper header to output
|
||
*/
|
||
function outPNG() {
|
||
header("Content-type: image/png");
|
||
ImagePng($this->image);
|
||
}
|
||
|
||
/**
|
||
* Output GD Image
|
||
*
|
||
* Will give the developer the GD resource for the graph that
|
||
* can be used to store the graph to the FS or other media
|
||
*
|
||
* @return Resource GD Image Resource
|
||
*/
|
||
public function getImage() {
|
||
return $this->image;
|
||
}
|
||
|
||
/**
|
||
* Output GD Image
|
||
*
|
||
* Alias for eqGraph::getImage()
|
||
*
|
||
* @return Resource GD Image resource
|
||
*/
|
||
public function outGD() {
|
||
return $this->getImage();
|
||
}
|
||
} //end class 'eqGraph'
|
||
?>
|