SVGGraph 2.15
Published
The new version 2.15 of SVGGraph contains three new graph types and some substantial internal changes to the existing grid-based graphs. These changes are there to support drawing a second Y-axis on the right hand side of the bar, line and scatter graphs.
The new graph types are all variations on the pie graph. The donut graph is a pie graph with a hole in the middle where you can put an optional label. There is an option for how large the hole is, but apart from that it behaves like a normal pie graph. In case you are wondering, I spelled it “donut” instead of “doughnut” because of the shorter spelling, making the class and filename shorter too.
The polar area graph is a pie graph where the angle of each slice remains constant, with the value represented by the area of the slice instead. One advantage of this type of graph over a standard pie graph is that zero values are visible as gaps in the graph. The example above shows that my dough recipe has no badger in it, which could be quite reassuring.
The exploded pie graph is the standard pie graph with extra options to explode some or all of its slices away from the centre. The slices can be exploded based on their value, or you can used structured data to explode individual slices by arbitrary amounts. How to use these explode options and the donut and polar area graphs are described in detail on the Pie Graphs page.
The dual-Y axis option for multi-dataset bar, line and scatter graphs is
enabled with the new dataset_axis option, which specifies which
of the two Y-axes each dataset should be plotted against. The example below
displays two datasets, one with a maximum value of 19,000 and the other with
a maximum of 45, on the same graph with an axis at each side.
This example is taken from the new Dual Y-axis graphs page, where there are some other examples and more explanation, including how the appearance of each axis can be controlled individually using the updated axis options.
The updated SVGGraph files are available from the downloads page.