lpslot, lpinterp — Computes a new set of poles from the interpolation between two analysis.
islot1 -- slot where the first analysis was stored
islot2 -- slot where the second analysis was stored
kmix -- mix value between the two analysis. Should be between 0 and 1. 0 means analysis 1 only. 1 means analysis 2 only. Any value in between will produce interpolation between the filters.
lpinterp computes a new set of poles from the interpolation between two analysis. The poles will be stored in the current lpslot and used by the next lpreson opcode.