The two options in the COORDINATES statement give the name of the variables in the DATA= data set that contains the values of the x and y coordinates of the conditioning data. You must specify the COORDINATES statement when you specify an input data set with the DATA= option in the PROC SIM2D statement.
Only one COORDINATES statement is allowed, and it is applied to all SIMULATE statements that have the VAR= specification. In other words, it is assumed that all the VAR= variables in all SIMULATE statements have the same x and y coordinates.
You can abbreviate the COORDINATES statement as COORD.