# PyX — Example: splitgraphs/splitatvalue.py

## Split axis at certain values

from pyx import * pf = graph.data.paramfunction g = graph.graphxy(width=8, x=graph.axis.split()) g.plot(pf("k", -1, 1, "x, y = splitatvalue(k, -0.9, 0.9), k**100", points=1000)) g.writeEPSfile("splitatvalue") g.writePDFfile("splitatvalue") g.writeSVGfile("splitatvalue")

### Description

A typical use-case for a split axis is to use some special positions on the axis to mark the axis breaks. For that the `splitatvalue`

function is available in all places, where expressions are evaluated in the `graph.data`

classes. Here we create a special parametric function where split positions for the x axis are added by the `splitatvalue`

function and the y function is a simple polynomial of high order. Note that you can set several split positions by additional parameters of the `splitatvalue`

function. In that case the `splitatvalue`

function marks odd regions to be a "None", by which those data values are ignored by the `splitaxis`

instance.