In article <firstname.lastname@example.org>, email@example.com (New2IDL) writes:
> I need help with the incomplete gamma function with real but negative
>fraction value of x. I found the M_Igamma(x,a)in Meron
>which works for both real and complex x. However, I notice that
>M_Igamma (x,a), for a real but negative fraction value of x, give
>only the real part. If any body knows how to deal with this problem
>please help me. You might use the following arguments: x=-0.069, a=
>2.2. Thank you very much for your help in advance.
Well, I can actually help you on this one. First, though, I suggest
you use the updated version of the routine (called Igamma_mm), you can
find it in my library on the RSI users contribution page.
Now, as for your question, Igamma_mm returns an output which is of the
same numerical type as x (no lower than float, though). So, if x is real,
so will be the output. If you want a full complex output, you need
complex input. See below:
IDL> print, igamma_mm(-0.069,2.2)
IDL> print, igamma_mm(complex(-0.069),2.2)
( 0.000976233, 0.000709275)
Hope this helps.
Mati Meron | "When you argue with a fool,
firstname.lastname@example.org | chances are he is doing just the same"