The gnum is the group number and must be in the range 1 to MXGRP-MXMOD (typically 60).
def is the group definition and can be either
a) A single number. The number corresponds to a vector number in the main data array. Thus "DGroup 2 2" would define group 2 to be the second vector, which is the default.
b) Four numbers. If you think of the main data array to be a two dimensional array with coordinates corresponding to the row and vector numbers, then the first two numbers define a row, vector coordinate of one corner and the second set form the other corner. Thus "DGroup 4 5 3 10 3" would define group 4 to be rows 5 through 10 of vector 3, and "DGroup 4 1 1 10 20" would cause group 4 to include rows 1 through 10 and vectors 1 to 20.
c) Either the word Model or Residual. By default, PLT reserves the high numbered groups (typically 61 to 64) to contain the model. However if you want to plot the same model in different window than the default you can define a new group to be that model The "DGroup 3 Res" command would cause group 3 to contain the current model residuals. The data min and max values are recomputed every time the model is changed. Of course, PLT does not change the scale unless you issue a "Rescale" command.
PLT> MO 1 CO ! Define a COnstant model 23 ! Starting parameter PLT> DGroup 2 Res ! Group 2 is the model residuals PLT> YPL 2 ! Plot group 2 in current window PLT> R Y ! Rescale and replot PLT> FIT ! Fit PLT> P ! Replot using the original scale PLT> R Y ! Rescale using currng residual min/max valuesexamples
PLT> DGroup 2 2 ! Group 2 is vector 2 (the PLT default) PLT> DGroup 2 1 2 10 2 ! Group 2 is rows 1 to 10 of vector 2 PLT> DGroup 2 2 1 10 99 ! Group 2 is now two dimensional, consisting ! of rows 2 through 10 and vectors 1 to 99. PLT> Dgroup 2 Res ! Group 2 is now the model residuals.