def d9.neg
import emerging-ezaudio@0.4.0.0/src/mp3_syn.bend as Mp3Synimport Base
278# negate the odd bins of a sine DCT
279def d9.neg(+ys: List<&2, F32>) -> List<&2, F32>:
280 f.set(f.set(f.set(f.set(ys, 1, F32.neg(f.at(ys, 1))), 3, F32.neg(f.at(ys, 3))), 5,
281 F32.neg(f.at(ys, 5))), 7, F32.neg(f.at(ys, 7)))