Functional spread/box plot

Functional spread/box plot plots various measures of the spread of data against a continuous variable. These measures include: interquartile range, parametric and non-parametric confidence intervals, standard deviation, or arbitrary percentiles. The spread is indicated by a shaded region, with a central line indicating the primary metric (mean or median). Additional percentiles, outliers, and the limits of the data may also be plotted. Data from multiple functions may be overlaid.