On 10/29/2014 12:33 PM, Denis Davydov wrote:
Dear all,
I am trying to use the associated Legendre polynomials,
but I am confused about the sign.
I would expect P_1^1(cos(phi)) = sin(phi) > 0 and
therefore to have the normalised polynomial also positive.
However, it seems that there is a (-1)^m multiplier
compared to the expression I see in several books.
Could someone please clarify this issue for me?
Kind regards,
Denis
As stated in the documentation, GSL follows Abramowitz and Stegun, and
you can see from eq 8.6.6 of their book that the (-1)^m factor is
included in the definition, so P11 = -sin(theta)
