*VMASK, Par
Specifies an array parameter as a masking vector.
Specifies the name of the parameter whose values are to be checked for
each resulting row operation. The mask vector usually contains only 0 (for
false) and 1 (for true) values. For each row operation the corresponding
mask vector value is checked. A true value allows the operation to be done.
A false value skips the operation (and retains the previous results). A
mask vector can be created from direct input, such as M(1) = 1,0,0,1,1,0,1;
or from the DATA function of the *VFILL command. The NOT
function of the *VFUN command can be used to reverse the
logical sense of the mask vector. The logical compare operations (LT, LE,
EQ, NE, GE, and GT) of the *VOPER command also produce
a mask vector by operating on two other vectors. Any numeric vector can be
used as a mask vector since the actual interpretation assumes values less
than 0.0 are 0.0 (false) and values greater than 0.0 are 1.0 (true). If the
mask vector is not specified (or has fewer values than the result vector),
true (1.0) values are assumed for the unspecified values. Another skip control
may be input with NINC on the *VLEN command.
If both are present, operations occur only when both are true. The mask
setting is reset to the default (no mask)
after each *VXX or *MXX operation.
Use *VSTAT to list settings.
This command is valid in any processor.