void erfscales(nydiv,y, npts)  ERFPLT.C Level 2
int nydiv The number of y axis divisions.
float *y The array of y data.
int npts The number of data points in the y array.
The erfscales() routine is the self-scaling routine for ERF plots. It uses the y data to calculate the y 
axis scaling parameters and then calls erfgrid(). The arguments for erfscales() are similar to the y axis arguments of 
the scales() routine.