The function smoothing procedures are extremely useful for comparing sets of data which may not have the same x-values. For instance, by smoothing two different datasets on the same sample settings, one can save the results to two tables, paste the tables together and plot the difference. Tremendously useful!
However, sometimes the data you want to compare should be step-wise. This is why we have "with steps" and "with fsteps" as plotting options. However, it is currently impossible to compare two sets of data if one is step-wise and the other isn't. For instance, it is impossible to execute filledcurves between two plots like that, or to subtract the difference and plot the result.
I propose "smooth step", an utterly simple smoothing function which accomplishes the goal by sampling the data according to a step function, as opposed to splines, gaussians, etc.. Moreover, it make it significantly easier to address my concerns in "Filled Steps".