function df=d1data(dsysl,rowd)
 [ddd,ddrp,ddindv,dder] = vunpck(rowd);
 [ddrows,ddcols] = size(ddd);
 dddn = ddd(:,ddcols*ones(1,ddcols)).\ddd;
 rowd(1:ddrows,1:ddcols) = dddn;
 [mtype,mrows,mcols,mnum] = minfo(rowd);
 omega = getiv(rowd);
 dsysl_g = frsp(dsysl,omega);
 sf = sel(dsysl_g,1,1);
 df = vabs(mmult(sf,sel(rowd,1,1)));
