Subroutine:   ARITH

Purpose:      Do an arithmetic operation on two real arrays and store
              the result in a third one. This routine checks for BLANK
              values.

Category:     ARRAY

File:         arith.c

Author:       K.G. Begeman

Use:          CALL ARITH( ARRAY1,    input        real array
                          OP,        input        character
                          ARRAY2,    input        real array
                          ARRAY3,    output       real array
                          NUMBER )   input        integer

              ARRAY1    input array.
              OP        character  operand ('+','-','*','/').
              ARRAY2    input array.
              ARRAY3    output array.
              NUMBER    number of operations.

Description:  For every element of the arrays 1, 2 and 3 the
              following operation is performed:
              ARRAY3 = ARRAY1 'OP' ARRAY2
              The arrays need not be different. OP can be '+', '-', '*'
              or '/'. When it is not one of these four, ARRAY3 is
              filled with BLANKs. Other errors (e.g. zero divide) also
              result in a BLANK value.

Example:      Add 100 elements of array A to array B and store the
              result in B.
              CALL ARITH(A,'+',B,B,100)

Updates:      Jul 21, 1989: KGB, original document.