Buenas noches, estoy tratando de mostrar un grafico de barras, con el siguiente codigo
<html>
<head>
<script type="text/javascript">
google.charts.load('current', {'packages':['corechart']});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
var jsonData = $.ajax({
url: "prueba.php",
dataType: "json"
}).responseText;
var data = new google.visualization.DataTable();
data.addColumn('string', 'sede');
data.addColumn('number', 'sema');
data.addColumn('number', 'tfre');
data.addColumn('number', 'tapli');
for (var i = 0; i < jsonData.length; i++) {
var sede = jsonData[i].['sede'];
var sema = jsonData[i].['sema'];
var tfre = jsonData[i].['tfre'];
var tapli = jsonData[i].['tapli'];
data.addRow([sede, sema, tfre, tapli]); <!-- Codificamos las tres variables en una fila-->
};
var chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));
chart.draw(data, {width: 400, height: 240});
}
</script>
</head>
<body>
<div id="chart_div"></div>
</body>
</html>
[{"sede":"AREQUIPA","sema":"1","tfre":"0","tapli":"0"},{"sede":"CAJAMARCA","sema":"1","tfre":"0","tapli":"0"},{"sede":"CALLAO","sema":"1","tfre":"0","tapli":"0"},{"sede":"CHICLAYO","sema":"1","tfre":"0","tapli":"0"},{"sede":"CORONEL PORTILLO-PUCALLPA","sema":"1","tfre":"0","tapli":"0"}]