Hello,

How does one interpret the subscript on a gamma function? For example, in the two parameter Gamma Cumulative Distribution Function:

What does the subscript mean in terms of how I should evaluate the gamma function.

Thanks

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- June 25th 2011, 07:36 AMrainerGamma CDF
Hello,

How does one interpret the subscript on a gamma function? For example, in the two parameter Gamma Cumulative Distribution Function:

What does the subscript mean in terms of how I should evaluate the gamma function.

Thanks - June 25th 2011, 07:50 AMGuyRe: Gamma CDF
I believe that denotes the incomplete gamma function.

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There is no closed form expression for this guy as a function of . If you fix and try to write as a function of you can sometimes do that, particularly if is a positive integer. - June 26th 2011, 07:46 AMrainerRe: Gamma CDF
Any advice as to how I might take the derivative of this w.r.t. alpha and beta?

- June 26th 2011, 08:01 AMGuyRe: Gamma CDF
You can but it probably will not be so useful for whatever you are doing. To take derivative wrt you may interchange integration and differentiation. So

.

To take derivative wrt you can use (chain rule + fundamental theorem of calculus). You can't get rid of the integrals though.