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.
New HTML datagrid
In the April 2025 release a new datagrid object
was added.
This makes it easy to add static or dynamic data
tables to your pages. It can be used whether you use the
canvas or SVG libraries or entirely standalone.
Download
Get the latest version of RGraph (version 6.22, 24th June 2025) 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.The strokeRect function
The strokeRect function is used for drawing rectangles on your canvas. As the name would suggest it does not fill them - only drawing the outline. An important thing to remember is that this is not a path function - so you don't have to call the stroke function - when you call the strokeRect function it immediately draws a rectangle on your canvas. It uses the strokeStyle setting for the color to use.
Arguments to the function
- The x-axis coordinate
- The y-axis coordinate
- The width of the rectangle
- The height of the rectangle
An example
<script> window.onload = function () { var canvas = document.getElementById("cvs"); var context = canvas.getContext('2d'); var x = 50; var y = 50; var width = 100; var height = 100; context.strokeStyle = 'red'; context.strokeRect(x, y, width, height); } </script>