npseed provides an interface for setting the random seed (and
  resetting the random number generator) used
  by np. The random number generator is used during the
  bandwidth search procedure to set the search starting point, and in
  subsequent searches when using multistarting, to avoid being trapped
  in local minima if the objective function is not globally concave.  Calling npseed will only affect the numerical search if it is
  performed by the C backend. The affected functions include:
  npudensbw, npcdensbw,
  npregbw, npplregbw, npqreg,
  npcmstest (via npregbw),
  npqcmstest (via npregbw),
  npsigtest (via npregbw).