Vẽ biểu đồ dạng cột (Bar Chart) với PHP

<?php
header("Content-type: image/gif");
$cells = array ( yeu=>1275, thuong=>1312, thu=>17 , ghet=>200);
$max = max( $cells );
$total = count ( $cells );
$totalwidth = 556;
$totalheight = 120;
$xgutter = 100; // left/right margin
$ygutter = 20; // top/bottom margin
$internalgap = 10; // space between cells
$bottomspace = 30; // gap at the bottom (in addition to margin)
$font = "elephant.ttf";
$graphCanX = ( $totalwidth - $xgutter*2 );
$graphCanY = ( $totalheight - $ygutter*2 - $bottomspace );// starting draw position x - axis
$posX = $xgutter; // starting draw pos - y -  axis
$posY = $totalheight - $ygutter - $bottomspace;
$cellwidth = (int) (( $graphCanX - ( $internalgap * ( $total-1 ) )) / $total) ;
 $textsize = (int)($bottomspace);
// adjust font size
while ( list( $key, $val ) = each ( $cells ) )
    {
     while ( 1 )
        {
        $box = ImageTTFbBox( $textsize, 0, $font, $key );
        $textWidth = abs( $box[2] );
        if ( $textWidth < $cellwidth )
            break;
        $textsize--;
        }
    }
$image = imagecreate( $totalwidth, $totalheight );
$red = ImageColorAllocate($image, 224, 224, 224);
$blue = ImageColorAllocate($image, 0, 0, 255 );
$black = ImageColorAllocate($image, 0, 0, 0 );
$grey = ImageColorAllocate($image, 100, 100, 100 );
 reset ($cells);
 while ( list( $key, $val ) = each ( $cells ) )
     {
     $cellheight = (int) (($val/$max) * $graphCanY);
     $center = (int)($posX+($cellwidth/2));
    imagefilledrectangle( $image, $posX, ($posY-$cellheight), ($posX+$cellwidth), $posY, $blue );
     $box = ImageTTFbBox( $textsize, 0, $font, $key );
     $tw = $box[2];
     ImageTTFText(    $image, $textsize, 0, ($center-($tw/2)),
             ($totalheight-$ygutter), $black, $font, $key );
     $posX += ( $cellwidth + $internalgap);
     }
 imagegif( $image );
 ?>

<?php header("Content-type: image/gif"); $cells = array ( yeu=>1275, thuong=>1312, thu=>17 , ghet=>200); $max = max( $cells ); $total = count ( $cells ); $totalwidth = 556; $totalheight = 120; $xgutter = 100; // left/right margin $ygutter = 20; // top/bottom margin $internalgap = 10; // space between cells $bottomspace = 30; // gap at the bottom (in addition to margin) $font = "elephant.ttf"; $graphCanX = ( $totalwidth - $xgutter*2 ); $graphCanY = ( $totalheight - $ygutter*2 - $bottomspace );// starting draw position x - axis $posX = $xgutter; // starting draw pos - y - axis $posY = $totalheight - $ygutter - $bottomspace; $cellwidth = (int) (( $graphCanX - ( $internalgap * ( $total-1 ) )) / $total) ; $textsize = (int)($bottomspace); // adjust font size while ( list( $key, $val ) = each ( $cells ) ) { while ( 1 ) { $box = ImageTTFbBox( $textsize, 0, $font, $key ); $textWidth = abs( $box[2] ); if ( $textWidth < $cellwidth ) break; $textsize--; } } $image = imagecreate( $totalwidth, $totalheight ); $red = ImageColorAllocate($image, 224, 224, 224); $blue = ImageColorAllocate($image, 0, 0, 255 ); $black = ImageColorAllocate($image, 0, 0, 0 ); $grey = ImageColorAllocate($image, 100, 100, 100 ); reset ($cells); while ( list( $key, $val ) = each ( $cells ) ) { $cellheight = (int) (($val/$max) * $graphCanY); $center = (int)($posX+($cellwidth/2)); imagefilledrectangle( $image, $posX, ($posY-$cellheight), ($posX+$cellwidth), $posY, $blue ); $box = ImageTTFbBox( $textsize, 0, $font, $key ); $tw = $box[2]; ImageTTFText( $image, $textsize, 0, ($center-($tw/2)), ($totalheight-$ygutter), $black, $font, $key ); $posX += ( $cellwidth + $internalgap); } imagegif( $image ); ?>