Internal soundgen function.
generatePath(path, pitchCands, ...)currently evaluated path
a matrix of multiple pitch candidates per fft frame. Each column is one fft frame, each row is one candidate (the last row is always "manual")
nothing really, but otherwise optim() complains
Internal helper function for postprocessing of pitch contours called by
pathfinding_slow. Generates proposals for new paths through
pitch candidates. It gives up and returns NA after 100 attempts, which stops
annealing - so the adaptation of pitch contour doesn't happen