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

Chapter 5 Fast Fourier Transforms 575
Real-to-complex two-dimensional FFT SRC2FT/DRC2FT
Output x The transformed data replaces the input if ier = 0 is
returned.
For a forward real-to-complex transform, the real part
of Z(m
1
,m
2
) is stored in x(2×m
1
−1,m
2
)and the
imaginary part is stored in x(2×m
1
,m
2
),
m
1
= 1, 2, ..., l1/2+1, m
2
= 1, 2, ..., l2. If needed,
the remaining (l1/2 − 1) × l2 complex output values
may be formed by using the conjugate-symmetry
condition.
For an inverse complex-to-real transform, the real
output point z(n
1
,n
2
) is stored in x(n
1
,n
2
),
n
1
= 1, 2, ..., l1, n
2
= 1, 2, ..., l2.
ier Status response:
ier = 0 Normal return—transform successful.
ier = −1 l1 ≤ 0.
ier = −2 l2 ≤ 0.
ier
= −3 ldx < l1+2.
ier
= −4 Probable error in ldx or dimensions of
x.