The Fourier transform that was standing wrong.

A discarded algorithm became usable software and then became a way to think about computation beyond software schedules.

A defect became a coordinate system.

BFFT began by refusing the accepted diagnosis of a forgotten Fourier transform. The transform was not repaired by tuning it harder. Its coordinates were changed until the hidden rotation geometry became ordinary, stable machinery. That repair produced a library with an inverse and understandable data order; it also opened routes toward transforms made from junctions and delays rather than a familiar processor recipe.

Everyone assumed
An abandoned real Fourier transform was inaccurate because its factor tree was intrinsically ill-behaved.
I asked
What if the tree was sound and its local coordinates were the actual defect?
I changed
Re-coordinate every quadratic leaf as the same normalized complex plane, then rebuild the inverse, the memory order, and the dataflow around that geometry.
Now there is
A working C and C++ transform library, alternate DIF, DIT, and diagonal traversals, and executable designs that describe Fourier computation as routed flow and phase delay.

Open the work