Viewing posts tagged with sparkline

Sparklines via PHP

Around 5 years ago I built a simple sparkline generation script in PHP. It wasn't very good, the lines were shaky even with antialias. During last weekend I thought I'd rebuild it from scratch to see how much better it would be second time around.

A few hours later and it was complete, the lines were thick, antialiased and almost identical in quality to the Google Image Charts version. I also added browser caching using the ETag header.

The key bit of logic that I failed to think of 5 years ago was to create the original sparkline larger than the desired size, then scale down by the same factor. The resizing naturally makes the lines smoother than imageantialias and imagesetthickness ever could.

Sparkline Examples

It's as easy as this to use:

<img src='sparkline.php?size=80x20&data=2,4,5,6,10,7,8,5,7,7,11,8,6,9,11,9,13,14,12,16&back=fff&line=5bb763&fill=d5f7d8' />

I use sparklines in a lot of my work related projects, as it's an intuitive way to display stats that only require a quick glance. Normally I'd use the Google Image Charts but has been depreciated since April 2012, and will become fully defunct in April 2015. Whilst there is the newer Google Charts library which uses HTML5, SVG, and JavaScript I prefer to use the image-only method for a leaner project with less bloat.

Check out the code on Github

20-Jun-2014 at 12:26pm