RAMPDOWN - Falling ramp function

Usage:
  • outsig = rampdown(siglen);

Description:

RAMPDOWN(siglen) will return a falling ramp function of length siglen. The ramp is a sinsosoidal starting from one and ending at zero. The ramp is centered such that the first element is always one and the last element is not quite zero, such that the ramp fits with following zeros.