samer@1: function so=design(sig,p,q)
samer@1: 	f1=rate(sig.source);
samer@1: 	f2=rate(sig);
samer@1: 	if isfield(sig.opts,'passband')
samer@1: 		relpass=2*sig.opts.passband/min(f1,f2);
samer@1: 	elseif isfield(sig.opts,'relpass')
samer@1: 		relpass=sig.opts.relpass;
samer@1: 	elseif isfield(sig.opts,'reltrans')
samer@1: 		relpass=(1-sig.opts.reltrans);
samer@1: 	else
samer@1: 		relpass=nan;
samer@1: 	end
samer@1: 
samer@1: 	if isnan(relpass) && ~isfield(sig.opts,'order')
samer@1: 		so=dsp.FIRRateConverter(p,q,mfilt.firsrc(p,q).Numerator);
samer@1: 	else
samer@1: 		tw = max(0.01,1-relpass)*min(f1,f2)/2;
samer@1: 		if isfield(sig.opts,'astop')
samer@1: 			fsrc=fdesign.rsrc(p,q,'Nyquist',max(p,q),'TW,Ast',tw,sig.opts.astop,p*f1);
samer@1: 		else
samer@1: 			if isfield(sig.opts,'order'), order = sig.opts.order;  else order = 12; end
samer@1: 			fsrc=fdesign.rsrc(p,q,'Nyquist',max(p,q),'N,TW',2*order*max(p,q),tw,p*f1);
samer@1: 		end
samer@1: 		so=design(fsrc,'kaiserwin','SystemObject',true);
samer@1: 	end
samer@1: end