Hello all, I am developing a new analytical solution for a problem in flow in porous media, and I need to write it in Fortran.(adsbygoogle = window.adsbygoogle || []).push({});

This solution contains the modified Bessel function of the first kind, I_n(x).

The order n is a real number, and it can be both negative and positive.

The argument x is real, and is always positive. Correct me if I'm wrong, but I believe this means I will never encounter a complex result.

I have looked in netlib, Numerical Recipes books, and an assortment of personal webpages (Alan Miller, JP Moreau), andI still can't find a Bessel_I subroutine that will compute for negative non-integer n. Obviously they all do a splendid job for positive n.

Alternatively, (and I have looked in functions.wolfram.com website) are you aware how I can compute this from other functions ? Gamma func ?

Thanks,

Manuel

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# Looking for fortran subroutine for I Bessel function with negative order

Can you offer guidance or do you also need help?

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