FUNCTION DIFFER,X ;+ ; function differ, call is D=DIFFER(X) ; returns differences between elements in the first dimension only ; 2 and 3-D arrays are handled as series of 1-D's ;- nd = SIZE(x) nx = nd(1) nd = nd(0) CASE 1 OF nd EQ 0: RETURN,x nd EQ 1: dx = x(1:*) - x(0:(nx-2)) nd EQ 2: dx = x(1:*,*) - x(0:(nx-2),*) nd EQ 3: dx = x(1:*,*,*) - x(0:(nx-2),*,*) ELSE: MESSAGE,'DIFFER is not intended for dimesnions >3' ENDCASE RETURN,dx END