In Gnuplot, when a function (as opposed to a data file) is plotted, only those plot styles which accept two columns of data can be used – for example, lines or points. This means that it is not possible to plot a function with errorbars. In PyXPlot, this is possible using the following syntax:
plot f(x):g(x) with yerrorbars
Two functions are supplied, separated by a colon; plotting proceeds as if a data file had been supplied, containing values of in column 1, values of
in column 2, and values of
in column 3. This may be useful, for example, if
measures the intrinsic uncertainty in
. The using modifier may also be used:
plot f(x):g(x) using 2:3
Here, would be plotted on the
-axis, against
on the
-axis. It should be noted, however, that the range of values of
used would still correspond to the range of the plot’s horizontal axis. If the above were to be attempted with an autoscaling horizontal axis, the result might be rather unexpected – PyXPlot would find itself autoscaling the
-axis range to the spread of values of
, but find that this itself changed depending upon the range of the
-axis.1
Footnotes