Re: Graphing - bar charts

Bar graphs are very easy to use with PHP. It's just a table columns of varying height. I wrote this a long time ago. To be honest it isn't very good code and I think I got the ideas from someone else. Regardless it should give you an idea. You basically pass in an array of dollar amounts and it outputs a bar graph. You can also manually adjust the scale of the graph by varying the values $minval and $maxval. The function "bar" makes a single bar of the graph. Use it at your own risk though. It is pretty poor PHP but it did the trick for me! ------------------------------------------------------------------------ //graph looks best when values are between 50 and 250 function bargraph ($bararray, $xminval, $xmaxval){ function bar($height,$val, $minval, $maxval){ $n_bars=count($bararray); $newmargin = $maxval - $minval; $newdifference = $height - $minval; $newchange = $newdifference / $newmargin; $newheight = 200 * $newchange + 25;

       echo ("<td valign=bottom>" .
      "<table bgcolor=#aa2222 height=" . $newheight .
      " cellpadding=0 cellspacing=0>");
      echo("<tr><td align=center valign=bottom>");
      echo ("<font color=#00000 size=-1 >");
      echo ("$");
      printf("%.2f", $val);
      echo ("</font>");
      echo ("</td></tr></table></td>");

} $n_bars=count($bararray); $border=0; echo("<table bgcolor=#a0a0a0 height=200 width=" . $n_bars*$width . " border=" . $border . " >"); if (!$xminval) $minval= min ($bararray); else $minval = $xminval; if (!$xmaxval)$maxval= max ($bararray); else $maxval = $xmaxval; for ($x = 0; $x<count($bararray); $x++){ bar($bararray[$x], $bararray[$x], $minval, $maxval); } echo("</table>"); } -------------------------------------------------------------------------- - Matt John W. Holmes wrote:

From: "Craig Hoffman" <choffman@katomic.com>

I am looking for an open source and simple PHP script that will graph (bar) a few MySQL fields. Does anyone have any recommendations?

The easiest way is to just have an image that you dynamically vary with width of <img src="dot.jpg" height="10" width="$width"> Or take a look at JPGraph, which offers a lot of features. ---John Holmes...