About
RGraph is a JavaScript charts library based on
HTML5 SVG and canvas. RGraph is mature (over 15 years
old) and has a wealth of features making it an ideal
choice to show charts on your website.
Download
Get the latest version of RGraph (version 6.17) from
the download page. 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 (£99) 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>