Hi there!
I have a problem when using $_POST variables in the following bar-graph. It seems as it cannot take values form a form, use them and then apear the graph in the resulting page.
The only thing I take is the page with the
--header
--the image's(bar-graph) borders
--footer
My code, if that can help is:
<?php include("header.php"); php?>
<?php
include("library.inc");
if ($_POST!='All') {
echo"Category: ";
category($_POST);
} else {
echo"The..........";
}
?>
<IMG SRC="b.php" HEIGHT="250" WIDTH="480">
<?php include("footer.php"); php?>
This is the b.php file:
<?php
include("library.inc");
dbconnection();
if ($_POST!='All') {
$column_name=$_POST;
$query="SELECT doc_ex.year,count(*)
FROM document AS doc_ex,citation, document AS doc_in
WHERE doc_ex.year between 1996 AND 2005
AND citation.lab_doc_no=doc_in.doc_no AND doc_in.category='$column_name'
GROUP BY doc_ex.year";
} else {
$query="SELECT doc_ex.year,count(*)
FROM document AS doc_ex,citation, document AS doc_in
WHERE doc_ex.year between 1996 AND 2005
AND citation.lab_doc_no=doc_in.doc_no
GROUP BY doc_ex.year";
}
$result = mysql_query($query) or die("Error in database interaction<BR>". mysql_error());
$strData='$data = array(';
while ($row = mysql_fetch_row($result)) {
$strData.="\"" .$row[0] . "\"" .'=> ' . $row[1] . ',';
}
$strData .=');';
eval($strData);
// create image
$width = 480;
$height = 250;
$image = imagecreate($width, $height);
// colors
$white = imagecolorallocate($image, 0xFF, 0xFF, 0xFF);
$navy = imagecolorallocate($image, 0x00, 0x00, 0x80);
$black = imagecolorallocate($image, 0x00, 0x00, 0x00);
$gray = imagecolorallocate($image, 0xC0, 0xC0, 0xC0);
// layout
$maxval = max($data);
$nval = sizeof($data);
$vmargin = 20; // top (bottom) vertical margin for title (x-labels)
$hmargin = 38; // left horizontal margin for y-labels
$base = floor(($width - $hmargin) / $nval); // distance between columns
$ysize = $height - 2 * $vmargin; // y-size of plot
$xsize = $nval * $base; // x-size of plot
// y labels and grid lines
$labelfont = 2;
$ngrid = $maxval; // number of grid lines ******$maxval/2
$dydat = ($maxval) / $ngrid; // data units between grid lines
$dypix = $ysize / ($ngrid+1 ); // pixels between grid lines
for ($i = 0; $i <= ($ngrid + 1); $i++) {
// iterate over y ticks
// height of grid line in units of data
$ydat = (int)($i * $dydat);
// height of grid line in pixels
$ypos = $vmargin + $ysize - (int)($i*$dypix);
$txtsz = imagefontwidth($labelfont) * strlen($ydat); // pixel-width of label
$txtht = imagefontheight($labelfont); // pixel-height of label
$xpos = (int)(($hmargin - $txtsz) / 2);
$xpos = max(1, $xpos);
imagestring($image, $labelfont, $xpos,
$ypos - (int)($txtht/2), $ydat, $black);
if (!($i == 0) && !($i > $ngrid)) {
imageline($image, $hmargin - 3,
$ypos, $hmargin + $xsize, $ypos, $gray);
// don't draw at Y=0 and top
}
}
// columns and x labels
$padding = 3; // half of spacing between columns
$yscale = $ysize / (($ngrid+1) * $dydat); // pixels per data unit
for ($i = 0; list($xval, $yval) = each($data); $i++) {
// vertical columns
$ymax = $vmargin + $ysize;
$ymin = $ymax - (int)($yval*$yscale);
$xmax = $hmargin + ($i+1)*$base - $padding;
$xmin = $hmargin + $i*$base + $padding;
imagefilledrectangle($image, $xmin, $ymin, $xmax, $ymax, $navy);
// x labels
$txtsz = imagefontwidth($labelfont) * strlen($xval);
$xpos = $xmin + (int)(($base - $txtsz) / 2);
$xpos = max($xmin, $xpos);
$ypos = $ymax + 3; // distance from x axis
imagestring($image, $labelfont, $xpos, $ypos, $xval, $black);
}
// plot frame
imagerectangle($image, $hmargin, $vmargin,
$hmargin + $xsize, $vmargin + $ysize, $black);
// flush image
header("Content-type: image/gif");
imagegif($image);
imagedestroy($image);
?>
Thanks! Cali.
