Machine contouring of frequency in a three-variable closed array
A method is described for machine plotting of contour lines representing the frequency of occurrence of sample data points in a three-variable closed array. The frequency values are in units of standard normal deviation from the expected frequency of the same sample size of a random distribution. The program is written in FORTRAN IV for an IBM 7094 computer and a CALCOMP plotter under off-line magnetic tape control.