php的gdchart介绍
gdchart是pecl的一个类库。也就是说它是一个c语言的扩展。虽然，目前php没有默认安装gdchart，但如果想使用，还是可以编译的。
gdchart最大的好处不仅是效率高，速度快，同时，另外一点则是，使用极为方便。以下是一些实例说明。
?
线形图：
add(array(2.5, 5.1, 8.6, 12.0, 15, 9, 8, 7));$chart->add(array(5.0, 8.0, 9.2, 10.2, 7, 8, 10, 9));$chart->add(array(8.0, 10.0, 14.0, 18.2, 16, 14, 12, 10));$chart->labels = array(jan,feb,mar,apr,may,jun,jul, aug);$chart->colors = array(0x1133aa, 0xaa3311, 0x33aa11);$chart->out(640,480,img_png);?>
?
自定义坐标线形图
add(array(2.5, 5.1, 8.6, 12.0, 15, 9, 8, 7));$chart->add(array(5.0, 8.0, 9.2, 10.2, 7, 8, 10, 9));$chart->add(array(8.0, 10.0, 14.0, 18.2, 16, 14, 12, 10));$chart->labels = array(jan,feb,mar,apr,may,jun,jul, aug);$chart->requested_ymin = 0;$chart->ylabel_density = 25;$chart->ylabel_fmt = %.0f;$chart->colors = array(0x001133aa, 0x00aa3311, 0x33aa11);$chart->out(640,480,img_png);?>
?
3d区域图
depth = 5;$chart->xtitle = fruits;$chart->xtitle_color = 0xffff00;$chart->bg_color = 0x112233;$chart->xlabel_color = 0xffffff;$chart->ylabel_color = 0xffffff;$chart->colors = array(0x30ffff00, 0x30ff00ff, 0x3000ffff);$chart->add(array(2.5, 5.1, 8.6, 12.0));$chart->add(array(5.0, 8.0, 9.2, 10.2));$chart->add(array(8.0, 10.0, 14.0, 18.2));$chart->labels = array(apples,oranges,melons,pears);$chart->out(640,480,img_png);?>
?
饼图
title = this is a sample pie chart;$chart->title_font = /usr/share/fonts/truetype/candy.ttf ;$chart->title_ptsize = 24;$chart->label_font = /usr/share/fonts/truetype/jester.ttf;$chart->label_ptsize = 16;$chart->edge_color = 0x000000;$chart->labels = array(red,green\r\n(exploded),lt blue,purple,missing,cyan,blue);$chart->add(array(12.5, 20.1, 2.0, 22.0, 5.0, 18.0, 13.0));$chart->missing = array(false, false, false, false, true, false, false);$chart->explode = array(0,40,0,0,0,0,0);$chart->pie_depth = 30;$chart->perspective = 0;$chart->pie_angle = 90;$chart->label_line = false;$chart->percent_labels = label_above;$chart->out(640,480,img_png);?>
?3d高低位闭合图
title = high-low-close on top of an area(volume) graph;$chart->depth = 5.0;$chart->angle = 50;$chart->annotation_font_size = font_tiny;$chart->anno_note = earnings\nreport;$chart->anno_point = 8;$chart->vol_color = 0x40806040;$chart->grid = tick_labels;$chart->ylabel_density = 40;$chart->hlc_style = hlc_connecting | hlc_i_cap | hlc_diamond;$chart->add_scatter(17.0, 3, scatter_triangle_up, 0x50808060, 30);$chart->add(array(17.8,17.1,17.3,17.2,17.1,17.3,17.3,17.3,17.1,17.5,17.4));$chart->add(array(16.4,16.0,15.7,15.25,16.0,16.1,16.8,16.5,16.8,16.2,16.0));$chart->add(array(17.0,16.8,16.9,15.9,16.8,17.2,16.8,17.0,16.9,16.4,16.1));$chart->add_combo(array(150.0,100.0,340.0,999.0,390.0,420.0,150.0,100.0,340.0,1590.0,700.0));$chart->labels =array(may,jun,jul,aug,sep,oct,nov,dec,jan,feb,mar,apr);$chart->out(640,480,img_png);?>
?
?