jpGraph中的透明背景

Question

I'm trying to achieve a line graph with transparent background, but so far, I can only set the background to a specific color. Since it's PNG, it should be possible though.

$linePlot = new LinePlot($plotData);
$linePlot->SetFillColor('#61a9f3@.6');

$graph = new Graph(300, 100);
$graph->SetScale('intint');

$graph->SetAlphaBlending();
$graph->SetMarginColor('black:1');
$graph->SetFrame(true,'black', 0);

$graph->Add($linePlot);
$graph->Stroke();

Result

Not transparent, but black

Answer 1

for me i have to put black instead of white to get transparency !

$graph->SetMarginColor('black:0');
$graph->SetFrame(true,'black:0', 1); //but this make labels/letters weird !!!
$graph->img->SetTransparent('black');

Now, when making multiple graphs in a picture, this doesn't work. I try making for each graph the transparency or to the final one (mgraph), and i get 'HTTP ERROR 500' (internal server !?!)

Answer 2

$graph->SetTheme($theme_class);
$graph->img->SetAntiAliasing(false);
$graph->title->Set('Filled Y-grid');
$graph->SetMarginColor('White:0.6'); 
$graph->SetFrame(true,'White:0.6',1); // The '1' here seems to be irrelevant
                                     // I've tried much larger numbers with no
                                     // change. This is supposed to be frame
                                     // width (in pixels). 
$graph->SetBox(false);

Reference: change margin color for a jpgraph

Answer 3

Transparent PNG image: $graph->img->SetTransparent("white"); works great!!!