function f = sing1(v) % f = sing1(v) % % is a defect function for the design of a singlet lens. % % The variables are % % v(1) = first surface curvature % v(2) = second surface curvature % % The defects are % % f(1) = power error (difference from target power 1/20) % f(2) = coma % Written by: John S. Loomis, University of Dayton % Revision: 8 Feb 2003 global cv th rn; cv(2)=v(1); % first surface curvature cv(3)=v(2); % second surface curvature yap = 5.0; uco = 0.1; scl = yap^2/2; ya = parax([yap 0],cv,th,rn); yc = parax([0 uco],cv,th,rn); f(1) = -ya(4,2)/ya(1,1) - 1/20; % power error w = ford(ya,yc,cv,th,rn,1); f(2) = w(2)/scl; % coma error f = f';