For simple charts have you tried Google? Just output the data in the right format and you can get nice charts, graphs etc - one of mine (please excuse any bad coding)
<script type="text/javascript" src="
<script type="text/javascript">
google.load("visualization", "1", {packages:["corechart"]});
google.setOnLoadCallback(drawChart);
function drawChart() {
var data = google.visualization.arrayToDataTable([
['The Hour', 'Views'],
<?php
for($p=0; $p<count($kount); $p++){
echo "['".$p."', ".$kount[$p]."],";
}
?>
]);
var options = {
title: 'Views',
pieSliceText: 'label',
};
var chart = new google.visualization.BarChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>