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Diffstat (limited to 'math/ieee/chap1/r4tx.f')
| -rw-r--r-- | math/ieee/chap1/r4tx.f | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/math/ieee/chap1/r4tx.f b/math/ieee/chap1/r4tx.f new file mode 100644 index 00000000..4e5649e8 --- /dev/null +++ b/math/ieee/chap1/r4tx.f @@ -0,0 +1,29 @@ +c +c----------------------------------------------------------------------- +c subroutine: r4tx +c radix 4 iteration subroutine +c----------------------------------------------------------------------- +c + subroutine r4tx(nthpo, cr0, cr1, cr2, cr3, ci0, ci1, ci2, ci3) + dimension cr0(2), cr1(2), cr2(2), cr3(2), ci0(2), ci1(2), ci2(2), + * ci3(2) + do 10 k=1,nthpo,4 + r1 = cr0(k) + cr2(k) + r2 = cr0(k) - cr2(k) + r3 = cr1(k) + cr3(k) + r4 = cr1(k) - cr3(k) + fi1 = ci0(k) + ci2(k) + fi2 = ci0(k) - ci2(k) + fi3 = ci1(k) + ci3(k) + fi4 = ci1(k) - ci3(k) + cr0(k) = r1 + r3 + ci0(k) = fi1 + fi3 + cr1(k) = r1 - r3 + ci1(k) = fi1 - fi3 + cr2(k) = r2 - fi4 + ci2(k) = fi2 + r4 + cr3(k) = r2 + fi4 + ci3(k) = fi2 - r4 + 10 continue + return + end |