public function addSinglePlot($data, $x = 0.5, $y = 0.5, $title = null)
{
$plot = new PiePlot(array_values($data));
$plot->SetSize($this->plot_size);
$plot->SetCenter($x, $y);
$plot->setLabelPos(0.6);
//$plot->setLegends(array_keys($data));
if ($title != null) {
$plot->title->set($title);
}
$this->grapher->Add($plot);
}
