JPGraph底部边缘与Legend开/关

Question

I have a problem with PHP Graphing library at JPGraph.net . I have a really simple LinePlot() and if i add a legend to the graph the bottom margin of the graph extend by circa 10 pixels. Making the graph legend Show() or Hide() doesn't make any difference the bottom margin is added to the graph right after the legend is associated with a lineplot.

Is there any solution to switch off this behaviour? Because i generate thumbnail size graphs (eg. 180x100) the bottom margin white area is quite "large".

For better understanding:

Left: starting point before legend is added

Right: After the legend is added, no other changes to the margins/code of the graph

Oops i dont have enough reputation to post images :(

left_good right_bad

Answer 1

Keep in mind the legend is more or less independent from the graph itself, it can be placed anywhere.

The margin of the graph itself can - in most cases - be modified using...

Graph::SetMargin($left_m, $right_m, $top_m, $bottom_m)

...(margin in pixels) which could look like this in your code:

$graph = new Graph(180,100);    
$graph->SetMargin(10,20,30,40);

/* followed by alot more code for your graph until... */
$graph->Stroke();

I advise looking into the extensive documentation which is included in the JPGraph packages, the classes are well documented and they offer alot of examples how to work with it.