PHP GD library dynamic generation of line chart instance code

/** * PHP GD library generates line chart, histogram, pie chart * by bbs.it-home.org */ $img _gao=170; $img _kuan=0; $jiange the interval between the =30;//and the point, the resulting image width automatically changes depending on how much data is passed in. Left blank $zuo =20;// $you =20;//Right Blank Leave blank on $shang =20;// Leave blank $xia =20;// $zuidashujuzhi = 1; $p _x = Array ();//Dot Horizontal $p _y = Array ();//Point ordinate $y _name=split (",", $_get["X_name"]); if ($_get["a"]== "") Die ("Error id:0"); $shuju =split (",", $_get["a"]); To get the longitudinal axis maximum value for ($i =0; $i<> if (!is_numeric ($shuju [$i])) die ("Error id:1"); if ($shuju [$i]> $zuidashujuzhi) $zuidashujuzhi = $shuju [$i]; } Get the image width $img _kuan= $zuo + $you +count ($shuju) * $jiange; Then create an image resource $image = Imagecreate ($img _kuan, $img _gao); Grey background $white = Imagecolorallocate ($image, 0xEE, 0xEE, 0xEE); The axes are shown in black $zuobiao _yanse = imagecolorallocate ($image, 0x00, 0x00, 0x00); Polyline is shown in blue $xian _yanse = imagecolorallocate ($image, 0x00, 0x00, 0xFF); Draw coordinates Horizontal Imageline ($image, $zuo, $img _gao-$xia, $img _kuan-$you/2, $img _gao-$xia, $zuobiao _yanse); longitudinal axis Imageline ($image, $zuo, $shang/2, $zuo, $img _gao-$xia, $zuobiao _yanse); Get the coordinates of each point for ($i =0; $i<> Array_push ($p _x, $zuo + $i * $jiange); Array_push ($p _y, $shang +round (($img _gao-$shang-$xia) * (1-$shuju [$i]/$zuidashujuzhi)); } Longitudinal axis Scale Imageline ($image, $zuo, $shang, $zuo +6, $shang, $zuobiao _yanse); Imagestring ($image, 1, $zuo/4, $shang, $zuidashujuzhi, $zuobiao _yanse); Imageline ($image, $zuo, $shang + ($img _gao-$shang-$xia) *1/4, $zuo +6, $shang + ($img _gao-$shang-$xia) *1/4, $zuobiao _ Yanse); Imagestring ($image, 1, $zuo/4, $shang + ($img _gao-$shang-$xia) *1/4, $zuidashujuzhi *3/4, $zuobiao _yanse); Imageline ($image, $zuo, $shang + ($img _gao-$shang-$xia) *2/4, $zuo +6, $shang + ($img _gao-$shang-$xia) *2/4, $zuobiao _ Yanse); Imagestring ($image, 1, $zuo/4, $shang + ($img _gao-$shang-$xia) *2/4, $zuidashujuzhi *2/4, $zuobiao _yanse); Imageline ($image, $zuo, $shang + ($img _gao-$shang-$xia) *3/4, $zuo +6, $shang + ($img _gao-$shang-$xia) *3/4, $zuobiao _ Yanse); Imagestring ($image, 1, $zuo/4, $shang + ($img _gao-$shang-$xia) *3/4, $zuidashujuzhi *1/4, $zuobiao _yanse); Horizontal scale for ($i =0; $i<> Imageline ($image, $zuo + $i * $jiange, $img _gao-$xia, $zuo + $i * $jiange, $img _gao-$xia-6, $zuobiao _yanse); Imagestring ($image, 1, $zuo + $i * $jiange-$jiange/4, $shang + ($img _gao-$shang-$xia) +2, $y _name[$i], $zuobiao _yanse); } Line $shuju _yanse_int=0; for ($i =0; $i<> if ($i +1<>count ($shuju)) { Imageline ($image, $p _x[$i], $p _y[$i], $p _x[$i +1], $p _y[$i +1], $xian _yanse); Imagefilledrectangle ($image, $p _x[$i]-1, $p _y[$i]-1, $p _x[$i]+1, $p _y[$i]+1, $xian _yanse); } } The last loop does not draw the final point effect, and there are additional Imagefilledrectangle ($image, $p _x[count ($shuju) -1]-1, $p _y[count ($shuju) -1]-1, $p _x[count ($shuju) -1]+1, $p _y[count ($shuju) -1]+1, $xian _yanse); Callout Data value for ($i =0; $i<> Imagestring ($image, 3, $p _x[$i]+4, $p _y[$i]-12, $shuju [$i], $zuobiao _yanse); } Set File header Header (' content-type:image/png '); Output image Imagepng ($image); Freeing resources Imagedestroy ($image); ?> Copy Code Second, use the method to insert the following code where the image needs to be displayed: Copy Code Description: Where A's value is calculated by itself; a text format is a string of several data concatenated by the ",", get method passed in. Since writing to the graphics in Chinese requires more PHP environment configuration, here is an HTML solution: You only need to dynamically generate a table to place the horizontal coordinate scale name according to the number of data. Example: for ($i =0; $i <12; $i + +) { } echo " ?> "; ". $i." Month Copy Code

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