<?php/*=======================================================================// File: 	JPGRAPH_LOG.PHP// Description:	Log scale plot extension for JpGraph// Created: 	2001-01-08// Author:	Johan Persson (johanp@aditus.nu)// Ver:		$Id: jpgraph_log.php,v 1.15.2.6 2004/06/12 21:41:37 aditus Exp $//// License:	This code is released under QPL// Copyright (C) 2001,2002 Johan Persson//========================================================================*/DEFINE('LOGLABELS_PLAIN',0);DEFINE('LOGLABELS_MAGNITUDE',1);//===================================================// CLASS LogScale// Description: Logarithmic scale between world and screen//===================================================class LogScale extends LinearScale {//---------------// CONSTRUCTOR    // Log scale is specified using the log of min and max    function LogScale($min,$max,$type="y") {	$this->LinearScale($min,$max,$type);	$this->ticks = new LogTicks();	$this->name = 'log';    }//----------------// PUBLIC METHODS	    // Translate between world and screen    function Translate($a) {	if( !is_numeric($a) ) {	    if( $a != '' && $a != '-' && $a != 'x' ) 		JpGraphError::Raise('Your data contains non-numeric values.');	    return 1;	}	if( $a < 0 ) {	    JpGraphError::Raise("Negative data values can not be used in a log scale.");	    exit(1);	}	if( $a==0 ) $a=1;	$a=log10($a);	return ceil($this->off + ($a*1.0 - $this->scale[0]) * $this->scale_factor);     }    // Relative translate (don't include offset) usefull when we just want    // to know the relative position (in pixels) on the axis	    function RelTranslate($a) {	if( !is_numeric($a) ) {	    if( $a != '' && $a != '-' && $a != 'x' ) 		JpGraphError::Raise('Your data contains non-numeric values.');	    return 1;	}	if( $a==0 ) $a=1;	$a=log10($a);	return round(($a*1.0 - $this->scale[0]) * $this->scale_factor);     }		    // Use bcpow() for increased precision    function GetMinVal() {	if( function_exists("bcpow") )	    return round(bcpow(10,$this->scale[0],15),14);	else	    return round(pow(10,$this->scale[0]),14);    }	    function GetMaxVal() {	if( function_exists("bcpow") )	    return round(bcpow(10,$this->scale[1],15),14);	else	    return round(pow(10,$this->scale[1]),14);    }	    // Logarithmic autoscaling is much simplier since we just    // set the min and max to logs of the min and max values.    // Note that for log autoscale the "maxstep" the fourth argument    // isn't used. This is just included to give the method the same    // signature as the linear counterpart.    function AutoScale(&$img,$min,$max,$dummy) {	if( $min==0 ) $min=1;		if( $max <= 0 ) {	    JpGraphError::Raise('Scale error for logarithmic scale. You have a problem with your data values. The max value must be greater than 0. It is mathematically impossible to have 0 in a logarithmic scale.');	}	$smin = floor(log10($min));	$smax = ceil(log10($max));	$this->Update($img,$smin,$smax);					    }//---------------// PRIVATE METHODS	} // Class//===================================================// CLASS LogTicks// Description: //===================================================class LogTicks extends Ticks{    var $label_logtype=LOGLABELS_MAGNITUDE;//---------------// CONSTRUCTOR    function LogTicks() {    }//---------------// PUBLIC METHODS	    function IsSpecified() {	return true;    }    function SetLabelLogType($aType) {	$this->label_logtype = $aType;    }	    // For log scale it's meaningless to speak about a major step    // We just return -1 to make the framework happy (specifically    // StrokeLabels() )    function GetMajor() {	return -1;    }    function SetTextLabelStart($aStart) {	JpGraphError::Raise('Specifying tick interval for a logarithmic scale is undefined. Remove any calls to SetTextLabelStart() or SetTextTickInterval() on the logarithmic scale.');    }    function SetXLabelOffset($dummy) {	// For log scales we dont care about XLabel offset    }    // Draw ticks on image "img" using scale "scale". The axis absolute    // position in the image is specified in pos, i.e. for an x-axis    // it specifies the absolute y-coord and for Y-ticks it specified the    // absolute x-position.    function Stroke(&$img,&$scale,$pos) {	$start = $scale->GetMinVal();	$limit = $scale->GetMaxVal();	$nextMajor = 10*$start;	$step = $nextMajor / 10.0;					$img->SetLineWeight($this->weight);						if( $scale->type == "y" ) {	    // member direction specified if the ticks should be on	    // left or right side.	    $a=$pos + $this->direction*$this->GetMinTickAbsSize();	    $a2=$pos + $this->direction*$this->GetMajTickAbsSize();					    $count=1; 	    $this->maj_ticks_pos[0]=$scale->Translate($start);	    $this->maj_ticklabels_pos[0]=$scale->Translate($start);	    if( $this->supress_first )		$this->maj_ticks_label[0]="";	    else {		if( $this->label_formfunc != '' ) {		    $f = $this->label_formfunc;		    $this->maj_ticks_label[0]=call_user_func($f,$start);			}		elseif( $this->label_logtype == LOGLABELS_PLAIN )		    $this->maj_ticks_label[0]=$start;			else		    $this->maj_ticks_label[0]='10^'.round(log10($start));	    }	    $i=1;	    for($y=$start; $y<=$limit; $y+=$step,++$count  ) {		$ys=$scale->Translate($y);			$this->ticks_pos[]=$ys;		$this->ticklabels_pos[]=$ys;		if( $count % 10 == 0 ) {		    if( $this->majcolor!="" ) {			$img->PushColor($this->majcolor);			$img->Line($pos,$ys,$a2,$ys);			$img->PopColor();		    }		    else			$img->Line($pos,$ys,$a2,$ys);		    $this->maj_ticks_pos[$i]=$ys;		    $this->maj_ticklabels_pos[$i]=$ys;		    		    if( $this->label_formfunc != '' ) {			$f = $this->label_formfunc;			$this->maj_ticks_label[$i]=call_user_func($f,$nextMajor);			    }		    elseif( $this->label_logtype == 0 )			$this->maj_ticks_label[$i]=$nextMajor;			    else			$this->maj_ticks_label[$i]='10^'.round(log10($nextMajor));		    ++$i;								    $nextMajor *= 10;		    $step *= 10;			    $count=1; 						}		else {		    if( $this->mincolor!="" ) $img->PushColor($this->mincolor);		    $img->Line($pos,$ys,$a,$ys);				    if( $this->mincolor!="" ) $img->PopCOlor();		}	    }			}	else {	    $a=$pos - $this->direction*$this->GetMinTickAbsSize();	    $a2=$pos - $this->direction*$this->GetMajTickAbsSize();		    $count=1; 	    $this->maj_ticks_pos[0]=$scale->Translate($start);	    $this->maj_ticklabels_pos[0]=$scale->Translate($start);	    if( $this->supress_first )		$this->maj_ticks_label[0]="";	    else {		if( $this->label_formfunc != '' ) {		    $f = $this->label_formfunc;		    $this->maj_ticks_label[0]=call_user_func($f,$start);			}		elseif( $this->label_logtype == 0 )		    $this->maj_ticks_label[0]=$start;			else		    $this->maj_ticks_label[0]='10^'.round(log10($start));	    }	    $i=1;				    for($x=$start; $x<=$limit; $x+=$step,++$count  ) {		$xs=$scale->Translate($x);			$this->ticks_pos[]=$xs;		$this->ticklabels_pos[]=$xs;		if( $count % 10 == 0 ) {		    $img->Line($xs,$pos,$xs,$a2);		    $this->maj_ticks_pos[$i]=$xs;		    $this->maj_ticklabels_pos[$i]=$xs;		    if( $this->label_formfunc != '' ) {			$f = $this->label_formfunc;			$this->maj_ticks_label[$i]=call_user_func($f,$nextMajor);			    }		    elseif( $this->label_logtype == 0 )			$this->maj_ticks_label[$i]=$nextMajor;			    else			$this->maj_ticks_label[$i]='10^'.round(log10($nextMajor));		    ++$i;		    $nextMajor *= 10;		    $step *= 10;			    $count=1; 						}		else		    $img->Line($xs,$pos,$xs,$a);			    }			}	return true;    }} // Class/* EOF */?>