tomwalters@0: %
tomwalters@0: %    Estimate fr from fpeak 
tomwalters@0: %    Toshio IRINO
tomwalters@0: %    10 June 98
tomwalters@0: %
tomwalters@0: %  function [fr, ERBw] = Fpeak2Fr(n,b,c,fpeak)
tomwalters@0: %    INPUT:  n,b,c : gammachirp param.
tomwalters@0: %            fpeak : peak freq.
tomwalters@0: %    OUTPUT: fr    : fr
tomwalters@0: %            ERBw  : ERBw(fr)
tomwalters@0: %
tomwalters@0: function [fr, ERBw] = Fpeak2Fr(n,b,c,fpeak)
tomwalters@0: 
tomwalters@0: if nargin < 4; help Fpeak2Fr; end;
tomwalters@0: 
tomwalters@0: n = n(:);
tomwalters@0: b = b(:);
tomwalters@0: c = c(:);
tomwalters@0: fpeak = fpeak(:);
tomwalters@0: 
tomwalters@0: %    fpeak = fr + c*b*ERBw(fr)/n 
tomwalters@0: %    ERBw(fr) = 24.7*(4.37*fr/1000 + 1) = k1*fr + k2  % M&G 1990
tomwalters@0: 
tomwalters@0: k1 = 24.7*4.37/1000;
tomwalters@0: k2 = 24.7;
tomwalters@0: 
tomwalters@0: fr = (fpeak - c.*b./n * k2)./(1 + c.*b./n * k1);
tomwalters@0: ERBw = k1*fr + k2;
tomwalters@0: 
tomwalters@0: