> (hint what is arctan(0+1j)?) > Well, at the risk of embarrassing myself, using arctan(x+iy) = I get: arctan(0+1i) = -i*log((0+i*1)/sqrt(0^2 + 1^2)) = -i*log(i/1) = -i*log(i) = -i*log(exp(i*pi/2)) = -i*i*pi/2 = pi/2... Is there some reason I'm forgetting (e.g., a branch cut convention or something) why this is wrong? DG