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* Debye functions.
@ 2017-03-24  9:20 Ed Smith-Rowland
  2017-03-25 21:24 ` maxgacode
  0 siblings, 1 reply; 3+ messages in thread
From: Ed Smith-Rowland @ 2017-03-24  9:20 UTC (permalink / raw)
  To: gsl-discuss

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


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2017-03-24  9:20 Debye functions Ed Smith-Rowland
2017-03-25 21:24 ` maxgacode
2017-03-27 19:04   ` Ed Smith-Rowland

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