Used internally. Prepares the x-axis scale for history/status plots.
Requires the ggplot2 package installed.
make_x_scale(x_value)An appropriate scale for the ggplot2 plot x-axis according to
the value specified in x_value.
single character string, determining whether the number of
adaptive analysis looks ("look", default), the total cumulated number of
patients randomised ("total n") or the total cumulated number of patients
with outcome data available at each adaptive analysis ("followed n") are
plotted on the x-axis.