;BUILD CODE TO EXTRACT FIELD. S=FILE/SUBFILE#, F=FIELD#, X=LOCAL VARIABLE NAME WHERE FIELD WILL BE STORED. CODE RETURNED IN Y
; DIFLAG["I" if internal value of field (no output transform)
V2
P
S
GREF(I,J,F)
;BUILD GLOBAL REFERENCE (I & J ARRAY FROM BIJ, CODE RETURNED IN F)
QD
CAL
Y
X
BIJ(S,F,I,J)
;BUILD I & J ARRAY. S=(SUB)FILE#, F=FIELD#
D2
GLRF(S,F,X,%)
;BUILD GLOBAL REFERENCE (S=(SUB)FILE#,F=FIELD NO.,%=CLOSE PARENTHESIS, RETURN PIECE IN %, X=OUTPUT VARIABLE.)