function [a,b]=notchCoeff(fnotchn,roc)
% --------------------------------------------------------------------------------------------
% Generate notch filter coefficients
% fnotchn = normalized notch frequency
% roc = module of the pole (roc <1 )
% --------------------------------------------------------------------------------------------
% Maurizio Varanini, Clinical Physiology Institute, CNR, Pisa, Italy
% For any comment or bug report, please send e-mail to: maurizio.varanini@ifc.cnr.it
% --------------------------------------------------------------------------------------------
if(nargin<2), roc=0.980; end
ro=1;
phi=2*pi*fnotchn;
% zeri
Zz=[ro*exp(1i*phi); ro*exp(-1i*phi)];
% poli
Zp=[roc*exp(1i*phi); roc*exp(-1i*phi)];
b = poly(Zz); % MA filter coefficients
a = poly(Zp); % AR filter coefficients
end %== function ================================================================
%