er is smoothed with a filter of
                   length FilterL to produce less variance in Orders

 The recommended procedure is to use a Hanning window for RPMMAP and using
 the (default) option Method='Hann5'. This method is much less sensitive
 to smearing errors.

   See also <a href="rpmmap.html" class="code" title="function [S,F,R] = rpmmap(x,fs,rpm,trpm,MinRpm,MaxRpm,DeltaRpm,Win,PhaseRef)">RPMMAP</a> <a href="rpmmaps.html" class="code" title="function [S,F,R] = rpmmaps(xs,rpm,OrdRes,MaxOrd,MinRpm