最近寫的一個GD圖庫用以生成橫豎柱狀圖和折線圖的類庫,算是一個教學例程吧  
<?
Class ImageReport{
var $X;//圖片大小X軸
var $Y;//圖片大小Y軸
var $R;//背影色R值
var $G;//...G.
var $B;//...B.
var $TRANSPARENT;//是否透明1或0
var $IMAGE;//圖片對像
//-------------------
var $ARRAYSPLIT;//指定用于分隔數值的符號
var $ITEMARRAY;//數值
var $REPORTTYPE;//圖表類型,1為豎柱形2為橫柱形3為折線形
var $BORDER;//距離
//-------------------
var $FONTSIZE;//字體大小
var $FONTCOLOR;//字體顏色
//--------參數設置函數
function setImage($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;  
}  
//----------------主體  
function PrintReport(){  
Header( "Content-type: image/gif");  
//建立畫布大小  
$this->IMAGE=ImageCreate($this->X,$this->Y);  
//設定畫布背景色  
$background=ImageColorAllocate($this->IMAGE,$this->R,$this->G,$this->B);  
if($this->TRANSPARENT=="1"){  
//背影透明  
Imagecolortransparent($this->IMAGE,$background);  
}else{  
//如不要透明時可填充背景色  
ImageFilledRectangle($this->IMAGE,0,0,$this->X,$this->Y,$background);  
}  
//參數字體文小及顏色  
$this->FONTCOLOR=ImageColorAllocate($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坐標軸  
function printXY(){  
//畫XY坐標軸*/  
$color=ImageColorAllocate($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軸  
ImageLine($this->IMAGE,$this->BORDER,$this->Y-$this->BORDER,$this->X-$this->BORDER,$this->Y-$this->BORDER,$color);//y軸  
//Y軸上刻度  
$rulerY=$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軸上刻度  
$rulerX=$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);  
}  
}  

//--------------豎柱形圖  
function imageColumnS(){  
$item_array=Split($this->ARRAYSPLIT,$this->ITEMARRAY);  
$num=Count($item_array);  
$item_max=0;  
for ($i=0;$i<$num;$i++){
$item_max=Max($item_max,$item_array[$i]);
}
$xx=$this->BORDER*2;  
//畫柱形圖  
for ($i=0;$i<$num;$i++){
srand((double)microtime()*1000000);
if($this->R!=255 && $this->G!=255 && $this->B!=255){  
$R=Rand($this->R,200);  
$G=Rand($this->G,200);  
$B=Rand($this->B,200);  
}else{  
$R=Rand(50,200);  
$G=Rand(50,200);  
$B=Rand(50,200);  
}  
$color=ImageColorAllocate($this->IMAGE,$R,$G,$B);  
//柱形高度  
$height=($this->Y-$this->BORDER)-($this->Y-$this->BORDER*2)*($item_array[$i]/$item_max);  
ImageFilledRectangle($this->IMAGE,$xx,$height,$xx+$this->BORDER,$this->Y-$this->BORDER,$color);  
ImageString($this->IMAGE,$this->FONTSIZE,$xx,$height-$this->BORDER,$item_array[$i],$this->FONTCOLOR);  
//用于間隔  
$xx=$xx+$this->BORDER*2;  
}  
}  

//-----------橫柱形圖  
function imageColumnH(){  
$item_array=Split($this->ARRAYSPLIT,$this->ITEMARRAY);  
$num=Count($item_array);  
$item_max=0;  
for ($i=0;$i<$num;$i++){
$item_max=Max($item_max,$item_array[$i]);
}
$yy=$this->Y-$this->BORDER*2;  
//畫柱形圖  
for ($i=0;$i<$num;$i++){
srand((double)microtime()*1000000);
if($this->R!=255 && $this->G!=255 && $this->B!=255){  
$R=Rand($this->R,200);  
$G=Rand($this->G,200);  
$B=Rand($this->B,200);  
}else{  
$R=Rand(50,200);  
$G=Rand(50,200);  
$B=Rand(50,200);  
}  
$color=ImageColorAllocate($this->IMAGE,$R,$G,$B);  
//柱形長度  
$leight=($this->X-$this->BORDER*2)*($item_array[$i]/$item_max);  
ImageFilledRectangle($this->IMAGE,$this->BORDER,$yy-$this->BORDER,$leight,$yy,$color);  
ImageString($this->IMAGE,$this->FONTSIZE,$leight+2,$yy-$this->BORDER,$item_array[$i],$this->FONTCOLOR);  
//用于間隔  
$yy=$yy-$this->BORDER*2;  
}  
}  

//--------------折線圖  
function imageLine(){  
$item_array=Split($this->ARRAYSPLIT,$this->ITEMARRAY);  
$num=Count($item_array);  
$item_max=0;  
for ($i=0;$i<$num;$i++){
$item_max=Max($item_max,$item_array[$i]);
}
//$xx=$this->BORDER;  
//畫柱形圖  
for ($i=0;$i<$num;$i++){
srand((double)microtime()*1000000);
if($this->R!=255 && $this->G!=255 && $this->B!=255){  
$R=Rand($this->R,200);  
$G=Rand($this->G,200);  
$B=Rand($this->B,200);  
}else{  
$R=Rand(50,200);  
$G=Rand(50,200);  
$B=Rand(50,200);  
}  
$color=ImageColorAllocate($this->IMAGE,$R,$G,$B);  
//柱形高度  
$height_now=($this->Y-$this->BORDER)-($this->Y-$this->BORDER*2)*($item_array[$i]/$item_max);  
if($i!="0"){  
ImageLine($this->IMAGE,$xx,$height_next,$xx+$this->BORDER,$height_now,$color);  
}  
ImageString($this->IMAGE,$this->FONTSIZE,$xx+$this->BORDER,$height_now-$this->BORDER/2,$item_array[$i],$this->FONTCOLOR);  
$height_next=$height_now;  
//用于間隔  
$xx=$xx+$this->BORDER;  
}  
}  

//--------------完成打印圖形YeMaoSheng.com  
function printAll(){  
ImageGIF($this->IMAGE);  
ImageDestroy($this->IMAGE);  
}  
//--------------調試  
function debug(){  
echo "X:".$this->X."<br>Y:".$this->Y;  
echo "<br>BORDER:".$this->BORDER;  
$item_array=split($this->ARRAYSPLIT,$this->ITEMARRAY);  
$num=Count($item_array);  
echo "<br>數值個數:".$num."<br>數值:";  
for ($i=0;$i<$num;$i++){
echo "<br>".$item_array[$i];  
}  
}  
}  

$report=new ImageReport;  
$report->setImage(600,300,255,255,255,1);//參數(長,寬,背影色R,G,B,是否透明1或0)  
$temparray="50,25,100,250,180,200,150,220,200,150,50,25,100,250,180,200,150,220,200,150";//數值,用指定符號隔開  
$report->setItem(',',$temparray,3,20);//參數(分隔數值的指定符號,數值變量,樣式1為豎柱圖2為橫柱圖3為折線圖,距離)  
$report->setFont(1);//字體大小1-10  
$report->PrintReport();  
//$report->debug();//調式之用  
?>