About
RGraph is a JavaScript charts library based on
HTML5 SVG and canvas. RGraph is mature (over 17 years
old) and has a wealth of features making it an ideal
choice to use for showing charts on your website.
Download
Get the latest version of RGraph (version 6.20, 1st December 2024) from
the download page. You can read the changelog here. There's also older versions available,
minified files and links to cdnjs.com hosted libraries.
License
RGraph can be used for free under the GPL or if
that doesn't suit your situation there's an
inexpensive (£129) commercial license available.Updated multi-color Line chart demo
Written by Richard Heyes, RGraph author, on 17th August 2022
Here's an updated version of a demo that's already
in the download archive.
The colors have been changed, tickmarks added, it
now uses the es6
spread
operator when
copying the configuration to the second chart, a
key has been added and the way that the gradients
are setup (using the beforedraw
RGraph event). All the code for it is shown below
and it should work as-is with version 6.08.
<script> // The data for both of the Line chart objects data = [8,4,6,2,1,5,3,3,4,8,9,8,4,1,3,4,7,8,8,5,6,4,1,2,3,4,2,3,1,5,3,5,1,5,6,8,7,9]; // Draw a Line chart that shows the fill of the chart line = new RGraph.Line({ id: 'cvs', data: data, options: { backgroundGrid: false, xaxisLabels: [ '','Q1\n2014','', '','Q2\n2014','', '','Q3\n2014','', '','Q4\n2014','', '','Q1\n2015','', '','Q2\n2015','', '','Q3\n2015','', '','Q4\n2015','' ], filled: true, backgroundGridColor: '#ddd', backgroundGridVlines: false, backgroundGridBorder: false, xaxis: false, yaxis: false, spline: true, yaxisScaleUnitsPost: '%', marginLeft: 50, marginTop: 50, marginBottom: 50, textColor: 'gray', colors: ['rgba(0,0,0,0)'], shadow: false, keyLabelsSize: 16, linewidth: 1, textSize: 16, textFont: "'Calibri Light', sans-serif" } }).on('beforedraw',function (obj) { var height = obj.canvas.height; // Create the gradient that is used as the fill color grad = obj.context.createLinearGradient(0,50,0,height - 50); grad.addColorStop(0, '#0003'); grad.addColorStop(0.2, '#0003'); grad.addColorStop(0.2, '#f0f3'); grad.addColorStop(0.4, '#f0f3'); grad.addColorStop(0.4, '#0a03'); grad.addColorStop(0.6, '#0a03'); grad.addColorStop(0.6, '#00f3'); grad.addColorStop(0.8, '#00f3'); grad.addColorStop(0.8, '#f003'); grad.addColorStop(1.0, '#f003'); // Apply the gradient to the charts fill obj.set({ filledColors: [grad] }); }).draw(); // Now create and draw the second, non-filled line that sits on // top of the fill. line2 = new RGraph.Line({ id: 'cvs', data: data, options: { ...line.properties, filled: false, labels: null, xaxis: false, yaxis: false, yaxisLabels: false, backgroundGrid: false, key: null, key: ['V Low','Low','Normal','High','V high'], keyColors: ['red','blue','#0a06','#f0f','black'], keyPosition: 'margin', keyPositionX: 65, keyColorShape: 'circle', responsive: [ {maxWidth: null, width: 700, height: 300,options: {linewidth:2}}, {maxWidth: 900, width: 500, height: 200,options: {linewidth:1}} ] } }).on('beforedraw', function (obj) { var height = obj.canvas.height; // Create the gradient that is used as the stroke color grad = obj.context.createLinearGradient(0,50,0,height - 50); grad.addColorStop(0, '#000'); grad.addColorStop(0.2, '#000'); grad.addColorStop(0.2, '#f0f'); grad.addColorStop(0.4, '#f0f'); grad.addColorStop(0.4, '#0a0'); grad.addColorStop(0.6, '#0a0'); grad.addColorStop(0.6, '#00f'); grad.addColorStop(0.8, '#00f'); grad.addColorStop(0.8, '#f00'); grad.addColorStop(1.0, '#f00'); obj.set({ colors: [grad] }); }).draw(); </script>