php生成折線圖代碼

/**


折線圖生成函數
**/
function line_stats_pic ( $value_y,$width,$high,$strong=1,$fix=0 )
{
//y值處理函數
function line_point_y ( $num,$width,$high,$max_num_add,$min_num_add,$y_pxdensity )
{
 $return=$high-floor ( ( $num-$min_num_add+$y_pxdensity ) / ( ( $max_num_add-$min_num_add ) /$high ) );
 return $return;
}

//參數處理
    $allnum=sizeof ( $value_y );
    $max_num=max ( $value_y );           //最大值
    $min_num=min ( $value_y );           //最小值
    $limit_m=$max_num-$min_num;            //極差
    $max_num_add=$max_num+$limit_m0.1;        //軸最大值
    $min_num_add=$min_num-$limit_m0.1;        //軸最小值
    $limit=$max_num_add-$min_num_add;         //極差-坐標軸y
    $y_pxdensity= ( $max_num_add-$min_num_add ) /$high;  //y軸密度
    $x_pxdensity=floor ( $width/$allnum );     //x軸密度
    reset ( $value_y );              //將數組指針歸零
    $i=0;
    foreach ( $value_y as $val )
    {
        $point_y[$i]=line_point_y ( $val,$width,$high,$max_num_add,$min_num_add,$y_pxdensity );
        $i++;
    }
    $zero_y=line_point_y ( 0,$width,$high,$max_num_add,$min_num_add,$y_pxdensity );  //零點的y值
    $empty_size_x= ( strlen ( $max_num ) > strlen ( $min_num ) ? strlen ( $max_num ) : strlen ( $min_num ) ) *5+3;          //左邊空白
//圖片流開始
    header ( "Content-type:image/png" );
    $pic=imagecreate ( $width+$empty_size_x+10,$high+13 );
    imagecolorallocate ( $pic,255,255,255 );  //背景色
    $color_1=imagecolorallocate ( $pic,30,144,255 ); //線條色
    $color_2=imagecolorallocate ( $pic,0,0,0 );   //黑色
    $color_3=imagecolorallocate ( $pic,194,194,194 );//灰色
//繪制網格
    imagesetthickness ( $pic,1 );       //網格線寬
    $y_line_width=floor ( $width/100 );    //縱網格線數目
    $y_line_density=$y_line_width==0 ? 0 :floor ( $width/$y_line_width ); //縱網格線密度
    $point_zero_y=$zero_y > $high ? $high : $zero_y;
    imagestring ( $pic,1,$empty_size_x-1,$high+4,"0",$color_2 ); //零點數軸標記
    for ( $i=1; $i <= $y_line_width; $i++ )  //繪制縱網格線
    {
        imagesetthickness ( $pic,1 );      //網格線寬
        imageline ( $pic,$y_line_density$i+$empty_size_x,0,$y_line_density$i+$empty_size_x,$high,$color_3 );
        imagesetthickness ( $pic,2 );      //軸點線寬
        imageline ( $pic,$y_line_density$i+$empty_size_x,$point_zero_y-4,$y_line_density$i+$empty_size_x,$point_zero_y,$color_2 );
        imagestring ( $pic,1,100$i+$empty_size_x-5,$high+4,$allnum/$y_line_width$i,$color_2 );  //數軸標記
    }
    $x_line_width=floor ( $high/30 );     //橫網格線數目
    $x_line_density=$x_line_width==0 ? 0 :floor ( $high/$y_line_width );  //橫網格線密度
    if ( $zero_y > $high )           //繪制橫網格線
    {
        imagestring ( $pic,1,0,$high-3,round ( $min_num_add,$fix ),$color_2 ); //零點數軸標記
        for ( $i=1; $i <= $x_line_width; $i++ )
        {
            imagesetthickness ( $pic,1 );     //網格線寬
            imageline ( $pic,0+$empty_size_x,$high-$x_line_density$i,$width+$empty_size_x,$high-$x_line_density$i,$color_3 );
            imagesetthickness ( $pic,2 );     //軸點線寬
            imageline ( $pic,0+$empty_size_x,$high-$x_line_density$i,3+$empty_size_x,$high-$x_line_density$i,$color_2 );
            imagestring ( $pic,1,0,$high-$x_line_density$i-3,round ( $limit/$x_line_width$i+$min_num_add,$fix ),$color_2 );  //數軸標記
        }
    }
    else
    {
        imagestring ( $pic,1,$empty_size_x-8,$zero_y,"0",$color_2 ); //零點數軸標記
        for ( $i=1; $i <= ceil ( $x_line_width/2 ); $i++ )
        {
            imagesetthickness ( $pic,1 );     //網格線寬
            imageline ( $pic,0+$empty_size_x,$zero_y-$x_line_density$i,$width+$empty_size_x,$zero_y-$x_line_density$i,$color_3 );
            if ( $zero_y+$x_line_density$i < $high )
            {
                imageline ( $pic,0+$empty_size_x,$zero_y+$x_line_density$i,$width+$empty_size_x,$zero_y+$x_line_density$i,$color_3 );
            }
            imagesetthickness ( $pic,2 );     //軸點線寬
            imageline ( $pic,0+$empty_size_x,$zero_y-$x_line_density$i,3+$empty_size_x,$zero_y-$x_line_density$i,$color_2 );
            if ( $zero_y+$x_line_density$i < $high )
            {
                imageline ( $pic,0+$empty_size_x,$zero_y+$x_line_density$i,3+$empty_size_x,$zero_y+$x_line_density$i,$color_2 );
            }
            imagestring ( $pic,1,0,$zero_y-$x_line_density$i-3,round ( $limit/$x_line_width$i,$fix ),$color_2 );   //數軸標記
            if ( $zero_y+$x_line_density$i < $high )
            {
                imagestring ( $pic,1,0,$zero_y+$x_line_density$i-3,round ( -$limit/$x_line_width*$i,$fix ),$color_2 );  //數軸標記
            }
        }
    }
//繪制軸線
    imagesetthickness ( $pic,2 );       //軸線寬
    imageline ( $pic,1+$empty_size_x,0,1+$empty_size_x,$high,$color_2 );
    if ( $zero_y > $high )           //x軸位置
    {
        imageline ( $pic,0+$empty_size_x,$high,$width+$empty_size_x,$high,$color_2 );
    }
    else
    {
        imageline ( $pic,0+$empty_size_x,$zero_y,$width+$empty_size_x,$zero_y,$color_2 );
    }
//產生折線
    $point_x=0;
    $j=0;
    imagesetthickness ( $pic,$strong );    //線條粗細
    while ( $j+1 < $allnum )
    {
        imageline ( $pic,$point_x+2+$empty_size_x,$point_y[$j],$point_x+$x_pxdensity+2+$empty_size_x,$point_y[$j+1],$color_1 );
        $point_x+=$x_pxdensity;
        $j++;
    }
    imagepng ( $pic );
    imagedestroy ( $pic );
}
/
函數描述及例子
參數說明：
$value_y -------- 包含你想生成折線圖的數組，要求鍵值從0開始遞增。
$width--------生成的折線圖的網格寬度（不算白邊）
$high--------高度
$strong-------線條粗細（默認為1）
$fix-------數據保留的位數（默認為取整）/
for ( $i=0; $i<100; $i++ )
{
    $value = rand ( 1,200 );
    $value_y[]=$value;
}
line_stats_pic ( $value_y,500,100,1,1 );
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