BANK procedure

Calculates the optimum aspect ratio for a graph (J. Ollerton & S.A. Harding).

Option

WINDOW = scalar

Window number; default 1

Parameters

Y = variates

Vertical coordinates

X = variates

Horizontal coordinates

ASPECTRATIO = scalars

Store the calculated aspect ratios

Description

BANK calculates the aspect ratio for a graph from the data to be plotted, specified as y and x variates. A window is set up using the FRAME directive so that the y and x dimensions are in the correct ratio; by default the window used is window 1, but this can be changed using the WINDOW option. The new window bounds are guaranteed to be within the existing definition; if the new aspect ratio is less than the current value the y upper bound of the window is reduced by an appropriate amount, otherwise the x upper bound is reduced. The aspect ratio can be saved using the parameter ASPECTRATIO.

Option: WINDOW. Parameters: Y, X, ASPECTRATIO.

Method

The aspect ratio is calculated from the X and Y variates of data using the Median-absolute-slope algorithm which centres the orientations of the individual line segments on 45 degrees. The specified window is resized to obtain the optimum aspect ratio within the plotting area; the existing axis margin sizes are preserved.

Action with RESTRICT

The Y and X variates can be restricted, however this restriction must be identical for both variates. Existing restrictions will not be altered.

References

Cleveland, W.S. (1987). Graphical Perception: The visual decoding of Quantitative Information on graphical displays of data. Journal of the Royal Statistical Society, Series A, 150, 192-229.

Cleveland, W.S. (1993). Visualizing Data. Hobart Press, Summit, New Jersey.