Arithmetic involving two Objects

The following commands perform arithmetic operations on elements of two primitives.

qcl>ADD   HDF_A,HDF_B,HDF_C
qcl>VADD  HDF_A,HDF_B,HDF_C
qcl>SUB   HDF_A,HDF_B,HDF_C
qcl>MUL   HDF_A,HDF_B,HDF_C
qcl>DIV   HDF_A,HDF_B,HDF_C

These perform HDF_C(j)=HDF_A(j)+HDF_B(j), where + can be +, -, * and / as appropriate, and j=1 to N where N is the number of elements in HDF_A. In each case the objects HDF_A and HDF_B must have the same number of elements and must be _REAL or _INTEGER. If HDF_C already exists it must be at least as large as HDF_A and if it doesn't exist then it will be created as a _REAL object with the dimensions of HDF_A. HDF_A and HDF_B can be slices of objects. All three parameters can be prefixed by <filename%> but if this is omitted then the default node is used. The command VADD is a special operation to add variance arrays in which negative values indicate gaps. If either HDF_A(j) or HDF_B(j) is negative then the result HDF_C(j) is set to -1.