HP MLIB User's Guide Vol. 2 7th Ed.

566 HP MLIB User’s Guide
CRC1FT/ZRC1FT Real-to-complex one-dimensional FFT
Working
Storage
work If iopt = −3, work is initialized for computing
transforms of length l.
If iopt ≠−3, work must have been initialized by a
previous call with this value of l in which iopt was −3.
Output z If iopt ≠−3, the transformed data replaces the input if
ier = 0 is returned.
For a forward real-to-complex transform, all l elements
of the transform are returned.
For an inverse complex-to-real transform, the real
result is stored in the real parts of z and the imaginary
parts of z are set to zero.
Not used as output if iopt = −3.
ier Status response:
ier = 0 Normal return—transform or
initialization successful.
ier = −1 l < 0.
ier = −2 l = 0.
ier = −3 Invalid value of iopt.
ier = −4 Insufficient dynamic memory
available for workspace.