An algorithm is described that approximates complex numbers by elements of the algebraic integers of
![Z[e^{2 \\pi i / 8}]](/images/tex/6024.gif)
with integer coordinates of at most a prescribed size. The motivating application is to reduce the dynamic range requirements of residue number system implementations of the discrete Fourier transform. The closest points to zero of
![Z[e^{2 \\pi i / 8}]_{M}](/images/tex/6025.gif)
gor any integer

are determined. A particular sequence of such points forms the basis of the algorithm. An example of

-bit
![Z[\\omega ]_{M}](/images/tex/6026.gif)
- approximations of the 128th roots of unity is considered. The algorithm yields

with scaling

is reduced to

.