<html>
<head>
<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
<script type="text/javascript">
google.charts.load('current', {'packages':['corechart']});
google.charts.setOnLoadCallback(drawChart);
var a=0;
var b=0;
var c=0;
var d=0;
function add() {
var maxNum = 10;
var minNum = 0;
a = Math.floor(Math.random() * (maxNum - minNum + 1)) + minNum;
b = Math.floor(Math.random() * (maxNum - minNum + 1)) + minNum;
c = Math.floor(Math.random() * (maxNum - minNum + 1)) + minNum;
d = Math.floor(Math.random() * (maxNum - minNum + 1)) + minNum;
drawChart();
}
function drawChart() {
var data = google.visualization.arrayToDataTable([
['Task', 'Hours per Day'],
['Work', a],
['Eat', b],
['Commute', c],
['Co', d],
]);
var options = {
title: 'My Daily Activities'
};
var chart = new google.visualization.PieChart(document.getElementById('piechart'));
chart.draw(data, options);
}
</script>
</head>
<body>
<input type="button" value="submit" onclick="add()"/>
<div id="piechart" style="width: 900px; height: 500px;"></div>
</body>
</html>