最近写的一个GD图库用以生成横竖柱状图和折线图的类库,算是一个教学例程吧  
<?
Class ImageReport{
var $X;//图片大小X轴
var $Y;//图片大小Y轴
var $R;//背影色R值
var $G;//...G.
var $B;//...B.
var $TRANSPARENT;//是否透明1或0
var $IMAGE;//图片对像
//-------------------
var $ARRAYSPLIT;//指定用于分隔数值的符号
var $ITEMARRAY;//数值
var $REPORTTYPE;//图表类型,1为竖柱形2为横柱形3为折线形
var $BORDER;//距离
//-------------------
var $FONTSIZE;//字体大小
var $FONTCOLOR;//字体颜色
//--------参数设置函数
function setImage($SizeX,$SizeY,$R,$G,$B,$Transparent){
$this->X=$SizeX;  
$this->Y=$SizeY;  
$this->R=$R;  
$this->G=$G;  
$this->B=$B;  
$this->TRANSPARENT=$Transparent;  
}  
function setItem($ArraySplit,$ItemArray,$ReportType,$Border){  
$this->ARRAYSPLIT=$ArraySplit;  
$this->ITEMARRAY=$ItemArray;  
$this->REPORTTYPE=$ReportType;  
$this->BORDER=$Border;  
}  
function setFont($FontSize){  
$this->FONTSIZE=$FontSize;  
}  
//----------------主体  
function PrintReport(){  
Header( "Content-type: image/gif");  
//建立画布大小  
$this->IMAGE=ImageCreate($this->X,$this->Y);  
//设定画布背景色  
$background=ImageColorAllocate($this->IMAGE,$this->R,$this->G,$this->B);  
if($this->TRANSPARENT=="1"){  
//背影透明  
Imagecolortransparent($this->IMAGE,$background);  
}else{  
//如不要透明时可填充背景色  
ImageFilledRectangle($this->IMAGE,0,0,$this->X,$this->Y,$background);  
}  
//参数字体文小及颜色  
$this->FONTCOLOR=ImageColorAllocate($this->IMAGE,255-$this->R,255-$this->G,255-$this->B);  
Switch ($this->REPORTTYPE){  
case "0":  
break;  
case "1":  
$this->imageColumnS();  
break;  
case "2":  
$this->imageColumnH();  
break;  
case "3":  
$this->imageLine();  
break;  
}  
$this->printXY();  
$this->printAll();  
}  
//-----------打印XY坐标轴  
function printXY(){  
//画XY坐标轴*/  
$color=ImageColorAllocate($this->IMAGE,255-$this->R,255-$this->G,255-$this->B);  
$xx=$this->X/10;  
$yy=$this->Y-$this->Y/10;  
ImageLine($this->IMAGE,$this->BORDER,$this->BORDER,$this->BORDER,$this->Y-$this->BORDER,$color);//X轴  
ImageLine($this->IMAGE,$this->BORDER,$this->Y-$this->BORDER,$this->X-$this->BORDER,$this->Y-$this->BORDER,$color);//y轴  
//Y轴上刻度  
$rulerY=$this->Y-$this->BORDER;  
while($rulerY>$this->BORDER*2){  
$rulerY=$rulerY-$this->BORDER;  
ImageLine($this->IMAGE,$this->BORDER,$rulerY,$this->BORDER-2,$rulerY,$color);  
}  
//X轴上刻度  
$rulerX=$rulerX+$this->BORDER;  
while($rulerX<($this->X-$this->BORDER*2)){  
$rulerX=$rulerX+$this->BORDER;  
//ImageLine($this->IMAGE,$this->BORDER,10,$this->BORDER+10,10,$color);  
ImageLine($this->IMAGE,$rulerX,$this->Y-$this->BORDER,$rulerX,$this->Y-$this->BORDER+2,$color);  
}  
}  

//--------------竖柱形图  
function imageColumnS(){  
$item_array=Split($this->ARRAYSPLIT,$this->ITEMARRAY);  
$num