function h1 = l1norm(H)% h1 = l1norm(H)	Compute the l1-norm of a z-domain transfer function.if strcmp(H.form,'zp')    sys = zpk(H.zeros,H.poles,H.k,1);elseif strcmp(H.form,'coeff')    sys = tf(H.num,H.den,1);else    fprintf(2,'%s: TF form %s is not recognized.\n', mfilename, H.form)endh1 = sum(abs(impulse(sys,100)));