在JPGraph中设置绘图区域背景颜色

Question

似乎$graph->SetColor('red'); 并没有真正做任何事情（来自JPGraph的example0.html：

<?php // content="text/plain; charset=utf-8"
require_once ('jpgraph/jpgraph.php');
require_once ('jpgraph/jpgraph_line.php');

// Some data
$ydata = array(11,3,8,12,5,1,9,13,5,7);

// Create the graph. These two calls are always required
$graph = new Graph(350,250);
$graph->SetScale('textlin');
$graph->SetColor('red'); #        <---- this does nothing 
// Create the linear plot
$lineplot=new LinePlot($ydata);
$lineplot->SetColor('blue');

// Add the plot to the graph
$graph->Add($lineplot);

// Display the graph

$graph->Stroke();
?>

我想念什么？

Answer 1

我发现我需要停用轴网格的显示，它似乎优先于背景颜色设置。 添加$graph->ygrid->Show(false, false); 颜色设置起作用。