[dygraphs.git] / tests / number-format.html

<!DOCTYPE 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="../dygraph-dev.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>
Commit	Line	Data
	1	<!DOCTYPE html>
	2	<html>
	3	<head>
	4	<title>Test of number formatting</title>
	5	<!--
	6	For production (minified) code, use:
	7	<script type="text/javascript" src="dygraph-combined.js"></script>
	8	-->
	9	<script type="text/javascript" src="../dygraph-dev.js"></script>
	10
	11	</head>
	12	<body>
	13	<p>The default formatting mimicks printf with %.<i>p</i>g where <i>p</i> is
	14	the precision to use. It turns out that JavaScript's toPrecision()
	15	method is almost but not exactly equal to %g; they differ for values
	16	with small absolute values (10^-1 to 10^-5 or so), with toPrecision()
	17	yielding strings that are longer than they should be (i.e. using fixed
	18	point where %g would use exponential).</p>
	19
	20	<p>This test is intended to check that our formatting works properly for a
	21	variety of precisions.</p>
	22
	23	<p>Precision to use (1 to 21):
	24	<input type="text" id="p_input" size="20" onchange="updateTable();"></p>
	25	<br>
	26	<br>
	27	<div id="content" style="font-family:'Courier New',monospace"></div>
	28
	29	<script type="text/javascript">
	30	// Helper functions for generating an HTML table for holding the test
	31	// results.
	32	createRow = function(columnType, columns) {
	33	var row = document.createElement('tr');
	34	for (var i = 0; i < columns.length; i ++) {
	35	var th = document.createElement(columnType);
	36	var text = document.createTextNode(columns[i]);
	37	th.appendChild(text);
	38	row.appendChild(th);
	39	};
	40	return row;
	41	};
	42
	43	createHeaderRow = function(columns) {
	44	return createRow('th', columns);
	45	};
	46
	47	createDataRow = function(columns) {
	48	return createRow('td', columns);
	49	};
	50
	51	createTable = function(headerColumns, dataColumnsList) {
	52	var table = document.createElement('table');
	53	table.appendChild(createHeaderRow(headerColumns));
	54	for (var i = 0; i < dataColumnsList.length; i++) {
	55	table.appendChild(createDataRow(dataColumnsList[i]));
	56	}
	57	return table;
	58	};
	59
	60	updateTable = function() {
	61	var headers = ['Dygraph.floatFormat()', 'toPrecision()',
	62	'Dygraph.floatFormat()', 'toPrecision()'];
	63	var numbers = [];
	64	var p = parseInt(document.getElementById('p_input').value);
	65
	66	for (var i = -10; i <= 10; i++) {
	67	var n = Math.pow(10, i);
	68	numbers.push([Dygraph.floatFormat(n, p),
	69	n.toPrecision(p),
	70	Dygraph.floatFormat(Math.PI * n, p),
	71	(Math.PI * n).toPrecision(p)]);
	72	}
	73
	74	// Check exact values of 0.
	75	numbers.push([Dygraph.floatFormat(0.0, p),
	76	0.0.toPrecision(p)]);
	77
	78	var elem = document.getElementById('content');
	79	elem.innerHTML = '';
	80	elem.appendChild(createTable(headers, numbers));
	81	};
	82
	83	document.getElementById('p_input').value = '4';
	84	updateTable();
	85	</script>
	86	</body>
	87	</html>