4 <title>Plotters demo
</title>
5 <script type=
"text/javascript" src=
"../dygraph-dev.js"></script>
7 <script type=
"text/javascript" src=
"data.js"></script>
8 <style type=
"text/css">
19 <p>This page demonstrates how to build custom plotters with dygraphs.
20 The
<a href=
"http://dygraphs.com/options.html#plotter">plotter
</a> option
21 allows you to write your own drawing logic. This can be used to achieve
22 powerful customization. View source to see how the examples work.
</p>
25 <p>Here a specialized
<a
26 href=
"http://dygraphs.com/options.html#plotter">plotter
</a> is used to draw
27 a bar plot rather than a line plot:
</p>
28 <div id=
"demodiv" class=chart
></div>
31 <p>Here a specialized
<a
32 href=
"http://dygraphs.com/options.html#plotter">plotter
</a> is used to
33 combined four series into a unified
"Candle" plot:
</p>
34 <div id=
"candlechart" class=chart
></div>
36 <h2>Bar
& Line Chart
</h2>
37 <p>The
<a href=
"http://dygraphs.com/options.html#plotter">plotter
</a>
38 option may be set on a per-series basis to create mixed charts:
</p>
39 <div id=
"barlinechart" class=
"chart"></div>
41 <h2>Multi-column Bar Chart
</h2>
42 <div id=
"multibar" class=
"chart"></div>
44 <h2>Mixed Error Bars and Lines
</h2>
45 <p>You can tweak the standard plotters list to achieve effects which would
46 be difficult otherwise, e.g. drawing series with only confidence intervals
47 and showing error bars only for some series.
</p>
48 <div id=
"mixed-error" class=
"chart"></div>
51 <p>See the
<a href=
"smooth-plots.html">smooth-plots demo
</a> for an example of a custom plotter which connects points using bezier curves instead of straight lines.
</p>
53 <script type=
"text/javascript">
55 function darkenColor(colorStr) {
56 // Defined in dygraph-utils.js
57 var color = Dygraph.toRGB_(colorStr);
58 color.r = Math.floor((
255 + color.r) /
2);
59 color.g = Math.floor((
255 + color.g) /
2);
60 color.b = Math.floor((
255 + color.b) /
2);
61 return 'rgb(' + color.r + ',' + color.g + ',' + color.b + ')';
64 // This function draws bars for a single series. See
65 // multiColumnBarPlotter below for a plotter which can draw multi-series
67 function barChartPlotter(e) {
68 var ctx = e.drawingContext;
69 var points = e.points;
70 var y_bottom = e.dygraph.toDomYCoord(
0);
72 ctx.fillStyle = darkenColor(e.color);
74 // Find the minimum separation between x-values.
75 // This determines the bar width.
76 var min_sep = Infinity;
77 for (var i =
1; i < points.length; i++) {
78 var sep = points[i].canvasx - points[i -
1].canvasx;
79 if (sep < min_sep) min_sep = sep;
81 var bar_width = Math.floor(
2.0 /
3 * min_sep);
83 // Do the actual plotting.
84 for (var i =
0; i < points.length; i++) {
86 var center_x = p.canvasx;
88 ctx.fillRect(center_x - bar_width /
2, p.canvasy,
89 bar_width, y_bottom - p.canvasy);
91 ctx.strokeRect(center_x - bar_width /
2, p.canvasy,
92 bar_width, y_bottom - p.canvasy);
97 document.getElementById(
"demodiv"),
98 "Date,Widgets Sold\n" +
106 title: 'Daily Widget Sales',
108 dateWindow: [ Date.parse(
"2012/07/20"), Date.parse(
"2012/07/26") ],
111 plotter: barChartPlotter
115 // The Candle chart plotter is adapted from code written by
116 // Zhenlei Cai (jpenguin@gmail.com)
117 // https://github.com/danvk/dygraphs/pull/
141/files
120 function candlePlotter(e) {
121 // This is the officially endorsed way to plot all the series at once.
122 if (e.seriesIndex !==
0) return;
124 var setCount = e.seriesCount;
126 throw
"Exactly 4 prices each point must be provided for candle chart (open close high low)";
131 var sets = e.allSeriesPoints;
132 for (var p =
0 ; p < sets[
0].length; p++) {
134 open : sets[
0][p].yval,
135 close : sets[
1][p].yval,
136 high : sets[
2][p].yval,
137 low : sets[
3][p].yval,
138 openY : sets[
0][p].y,
139 closeY : sets[
1][p].y,
140 highY : sets[
2][p].y,
146 var area = e.plotArea;
147 var ctx = e.drawingContext;
148 ctx.strokeStyle = '#
202020';
151 for (p =
0 ; p < prices.length; p++) {
155 var topY = area.h * price.highY + area.y;
156 var bottomY = area.h * price.lowY + area.y;
157 var centerX = area.x + sets[
0][p].x * area.w;
158 ctx.moveTo(centerX, topY);
159 ctx.lineTo(centerX, bottomY);
163 if (price.open
> price.close) {
164 ctx.fillStyle ='rgba(
244,
44,
44,
1.0)';
165 bodyY = area.h * price.openY + area.y;
168 ctx.fillStyle ='rgba(
44,
244,
44,
1.0)';
169 bodyY = area.h * price.closeY + area.y;
171 var bodyHeight = area.h * Math.abs(price.openY - price.closeY);
172 ctx.fillRect(centerX - BAR_WIDTH /
2, bodyY, BAR_WIDTH, bodyHeight);
177 var candleData =
"Date,Open,Close,High,Low\n" +
178 "2011-12-06,392.54,390.95,394.63,389.38\n" +
179 "2011-12-07,389.93,389.09,390.94,386.76\n" +
180 "2011-12-08,391.45,390.66,395.50,390.23\n" +
181 "2011-12-09,392.85,393.62,394.04,391.03\n" +
182 "2011-12-12,391.68,391.84,393.90,389.45\n" +
183 "2011-12-13,393.00,388.81,395.40,387.10\n" +
184 "2011-12-14,386.70,380.19,387.38,377.68\n" +
185 "2011-12-15,383.33,378.94,383.74,378.31\n" +
186 "2011-12-16,380.36,381.02,384.15,379.57\n" +
187 "2011-12-19,382.47,382.21,384.85,380.48\n" +
188 "2011-12-20,387.76,395.95,396.10,387.26\n" +
189 "2011-12-21,396.69,396.45,397.30,392.01\n" +
190 "2011-12-22,397.00,398.55,399.13,396.10\n" +
191 "2011-12-23,399.69,403.33,403.59,399.49\n" +
192 "2011-12-27,403.10,406.53,409.09,403.02\n" +
193 "2011-12-28,406.89,402.64,408.25,401.34\n" +
194 "2011-12-29,403.40,405.12,405.65,400.51\n" +
195 "2011-12-30,403.51,405.00,406.28,403.49\n" +
196 "2012-01-03,409.50,411.23,412.50,409.00\n" +
197 "2012-01-04,410.21,413.44,414.68,409.28\n" +
198 "2012-01-05,414.95,418.03,418.55,412.67\n" +
199 "2012-01-06,419.77,422.40,422.75,419.22\n" +
200 "2012-01-09,425.52,421.73,427.75,421.35\n" +
201 "2012-01-10,425.91,423.24,426.00,421.50\n" +
202 "2012-01-11,422.59,422.55,422.85,419.31\n" +
203 "2012-01-12,422.41,421.39,422.90,418.75\n" +
204 "2012-01-13,419.53,419.81,420.45,418.66\n" +
205 "2012-01-17,424.20,424.70,425.99,422.96\n" +
206 "2012-01-18,426.87,429.11,429.47,426.30\n" +
207 "2012-01-19,430.03,427.75,431.37,426.51\n" +
208 "2012-01-20,427.49,420.30,427.50,419.75\n" +
209 "2012-01-23,422.67,427.41,428.45,422.30\n" +
210 "2012-01-24,425.10,420.41,425.10,419.55\n" +
211 "2012-01-25,454.26,446.66,454.45,443.73\n" +
212 "2012-01-26,448.45,444.63,448.79,443.14\n" +
213 "2012-01-27,444.37,447.28,448.48,443.77\n" +
214 "2012-01-30,445.71,453.01,453.90,445.39\n" +
215 "2012-01-31,455.85,456.48,458.24,453.07\n" +
216 "2012-02-01,458.49,456.19,458.99,455.55\n" +
217 "2012-02-02,455.90,455.12,457.17,453.98\n" +
218 "2012-02-03,457.30,459.68,460.00,455.56\n" +
219 "2012-02-06,458.38,463.97,464.98,458.20\n" +
220 "2012-02-07,465.25,468.83,469.75,464.58\n" +
221 "2012-02-08,470.50,476.68,476.79,469.70\n" +
222 "2012-02-09,480.95,493.17,496.75,480.56\n" +
223 "2012-02-10,491.17,493.42,497.62,488.55\n" +
224 "2012-02-13,499.74,502.60,503.83,497.09\n" +
225 "2012-02-14,504.70,509.46,509.56,502.00\n" ;
228 document.getElementById(
"candlechart"),
231 plotter: candlePlotter
235 // Bar and Line chart
236 var short_data = data_nolabel();
237 short_data = short_data.split('
\n').slice(
0,
20).join('
\n');
240 document.getElementById(
"barlinechart"),
243 labels: ['Date', 'A', 'B'],
250 plotter: barChartPlotter
256 // Multiple column bar chart
257 function multiColumnBarPlotter(e) {
258 // We need to handle all the series simultaneously.
259 if (e.seriesIndex !==
0) return;
262 var ctx = e.drawingContext;
263 var sets = e.allSeriesPoints;
264 var y_bottom = e.dygraph.toDomYCoord(
0);
266 // Find the minimum separation between x-values.
267 // This determines the bar width.
268 var min_sep = Infinity;
269 for (var j =
0; j < sets.length; j++) {
270 var points = sets[j];
271 for (var i =
1; i < points.length; i++) {
272 var sep = points[i].canvasx - points[i -
1].canvasx;
273 if (sep < min_sep) min_sep = sep;
276 var bar_width = Math.floor(
2.0 /
3 * min_sep);
279 var strokeColors = g.getColors();
280 for (var i =
0; i < strokeColors.length; i++) {
281 fillColors.push(darkenColor(strokeColors[i]));
284 for (var j =
0; j < sets.length; j++) {
285 ctx.fillStyle = fillColors[j];
286 ctx.strokeStyle = strokeColors[j];
287 for (var i =
0; i < sets[j].length; i++) {
289 var center_x = p.canvasx;
290 var x_left = center_x - (bar_width /
2) * (
1 - j/(sets.length-
1));
292 ctx.fillRect(x_left, p.canvasy,
293 bar_width/sets.length, y_bottom - p.canvasy);
295 ctx.strokeRect(x_left, p.canvasy,
296 bar_width/sets.length, y_bottom - p.canvasy);
302 document.getElementById(
"multibar"),
306 plotter: multiColumnBarPlotter
309 // Mixed Error Bars and Lines
311 document.getElementById(
"mixed-error"),
317 plotter: Dygraph.Plotters.errorPlotter
320 plotter: Dygraph.Plotters.linePlotter,
321 strokePattern: Dygraph.DASHED_LINE