The axis definition at input of plot_sigma uses the incorrect 'xp' code instead of 'px'. Accordingly, the axis labels on the plot also display x' instead of px.
This is corrected here by using the at.axis_() function, allowing one of:
1, 'px' or 'PX' to describe the px axis (and so on…)
The axis definition at input of
plot_sigmauses the incorrect'xp'code instead of'px'. Accordingly, the axis labels on the plot also display x' instead of px.This is corrected here by using the
at.axis_()function, allowing one of:1,'px'or'PX'to describe the px axis (and so on…)'xp'is still accepted for compatibility.