6 May
2004
6 May
'04
8:58 p.m.
Further to the acos(z) issue, here's an example of a specific point which I think may be wrong. acos(1,-1) is (-0.904557,-1.06128) per Fractint's formula asin(1,-1) is (0.666239,-1.06128), also per Fractint's formula pi/2 - asin(1,-1) is (+0.904557,+1.06128) So my theory is that the acos(z) formula used in Fractint produces an answer with the wrong sign if real(z) * imag(z) < 0. The only other complex math library I have to hand is Python's, which also claims that acos(1,-1) is +ve. Regards, -- Edwin