dcos-dygraphs
Version:
dygraphs is a fast, flexible open source JavaScript charting library.
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HTML
<html>
<head>
<title>Test of number formatting</title>
<!--
For production (minified) code, use:
<script type="text/javascript" src="dygraph-combined.js"></script>
-->
<script type="text/javascript" src="../dist/dygraph.js"></script>
</head>
<body>
<p>The default formatting mimicks printf with %.<i>p</i>g where <i>p</i> is
the precision to use. It turns out that JavaScript's toPrecision()
method is almost but not exactly equal to %g; they differ for values
with small absolute values (10^-1 to 10^-5 or so), with toPrecision()
yielding strings that are longer than they should be (i.e. using fixed
point where %g would use exponential).</p>
<p>This test is intended to check that our formatting works properly for a
variety of precisions.</p>
<p>Precision to use (1 to 21):
<input type="text" id="p_input" size="20" onchange="updateTable();"></p>
<br>
<br>
<div id="content" style="font-family:'Courier New',monospace"></div>
<script type="text/javascript">
// Helper functions for generating an HTML table for holding the test
// results.
createRow = function(columnType, columns) {
var row = document.createElement('tr');
for (var i = 0; i < columns.length; i ++) {
var th = document.createElement(columnType);
var text = document.createTextNode(columns[i]);
th.appendChild(text);
row.appendChild(th);
};
return row;
};
createHeaderRow = function(columns) {
return createRow('th', columns);
};
createDataRow = function(columns) {
return createRow('td', columns);
};
createTable = function(headerColumns, dataColumnsList) {
var table = document.createElement('table');
table.appendChild(createHeaderRow(headerColumns));
for (var i = 0; i < dataColumnsList.length; i++) {
table.appendChild(createDataRow(dataColumnsList[i]));
}
return table;
};
updateTable = function() {
var headers = ['Dygraph.floatFormat()', 'toPrecision()',
'Dygraph.floatFormat()', 'toPrecision()'];
var numbers = [];
var p = parseInt(document.getElementById('p_input').value);
for (var i = -10; i <= 10; i++) {
var n = Math.pow(10, i);
numbers.push([Dygraph.floatFormat(n, p),
n.toPrecision(p),
Dygraph.floatFormat(Math.PI * n, p),
(Math.PI * n).toPrecision(p)]);
}
// Check exact values of 0.
numbers.push([Dygraph.floatFormat(0.0, p),
0.0.toPrecision(p)]);
var elem = document.getElementById('content');
elem.innerHTML = '';
elem.appendChild(createTable(headers, numbers));
};
document.getElementById('p_input').value = '4';
updateTable();
</script>
</body>
</html>