Basic HTML version of Foils prepared April 22 2000
| For DIF, the phases are of course reversed in the way the step through the binary digits of f(m) and GN(k,f) |
| One still has d phases labeled by p |
| At first recursion p=0 one is manipulating f(m) with highest binary index md-1 and forming GN(k,f) with binary index k0 |
| The first DIF computations are done at end of recursion and this is "natural" m=0 and kd-1 index for GN(k,f) |
| DIF has an identical parallel performance to DIT although some of the steps differ in detail |