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From: Ed Smith-Rowland <3dw4rd@verizon.net>
To: gsl-discuss@sourceware.org
Subject: Debye functions.
Date: Fri, 24 Mar 2017 09:20:00 -0000	[thread overview]
Message-ID: <213cda3e-0b6c-d4bb-ca4c-f868245b791b@verizon.net> (raw)

Greetings,

I've been looking at the Debye integrals

D_n(x) = \frac{n}{x^n}\int_{0}^{x} \frac{t^n}{e^t - 1}dt

The integrand is everywhere positive.

The definite integral must be zero for x=0.

The values returned by gsl debye functions start at one for x=0 and 
monotonically decrease.

The definite integral of a positive functions must start at zero and 
monotonically increase.

Is it possible that we have a complementary Debye integral? Perhaps scaled?

In any case, the functions can't match the formulas in the manual.

Thank you.

Ed Smith-Rowland


             reply	other threads:[~2017-03-24  9:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-24  9:20 Ed Smith-Rowland [this message]
2017-03-25 21:24 ` maxgacode
2017-03-27 19:04   ` Ed Smith-Rowland

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