GR4_RGIVE(NX,NY,CONV,R)
This subroutine passes a two-Dimensional array to GREG as the Regular Grid array used for mapping.
NX,NY Integers, array dimensions
CONV Real(KIND=8) array of dimension 6
It contains respectively
CONV(1) Reference pixel in X (First dimension of R)
CONV(2) X User coordinate value at CONV(1)
CONV(3) X User coordinate increment per pixel (may be negative)
CONV(4)-CONV(6) same as above for Y (Second dimension of R)
R REAL array (NX,NY) to be transferred.
If R is Real(KIND=4), the array is not physically copied but its address is
computed by GREG for later use. GREG will not modify anything in it. If
of type Real(KIND=8), virtual memory is allocated to create a Real(KIND=4) array of
same dimensions.