qcalc_smart.m

%%% little code to compute steady state "q" from creation+decay "wp,wm"
% wp=creation
% wm=destruction

function q=qdef(wp,wm);
% 1) most important line p=\Pi (wp_j/wm_{j+1})=S^+_n/S^-/n
p=cumprod(	wp(1:(end-1))	...
			./	...
		wm((1+1):end)	...
);
% 2) add p0=1
p=[1;p(:)];
% 3) normalize
q=p(:)/sum(p(:));