function y = fhmvmultiply(cc,x)

% y = fhmvmultiply(cc,x)

%

% Fast general Toeplitz-circulant matrix-vector multiplication

% used in fast Hankel matrix-vector multiplication

%

% Inputs

%   cc  Toeplitz-circulant converted from a Hankel

%   x   vector to be multiplied by the Hankel

% Ourput

%   y   product of the Hankel matrix and x

% Note. When c(m) does not match and r(1), c(m) wins

%       over r(1).



% Kevin Browne     McMaster Univ.  November 2007



n = length(x);

m = length(cc) - n + 1;



%

% reverse x

xrev = x(n:-1:1);



% expand xrev

xx = [xrev; zeros(m-1,1)];

%

% use fft to multiply circulant matrix-vector

yy = ifft(fft(cc).*fft(xx));



% extract the product

y = yy(1:m);