Mercurial > octave
diff libinterp/corefcn/psi.cc @ 20156:bd565f3e0ecb
psi: refactor to reduce code duplication.
* liboctave/numeric/lo-specfun.cc (psi): reduce code duplication by creating
Lanczos_approximation_psi() to be shared between the functions for complex
and real input. Also invert the order of the for loops (to sum smaller
numbers first, which will increase accuracy.
* libinterp/corefcn/psi.cc: adjust tolerance for the tests.
| author | Carnë Draug <carandraug@octave.org> |
|---|---|
| date | Sun, 03 May 2015 02:59:28 +0100 |
| parents | 1fae49e34a1a |
| children | 65e22ba879f0 |
line wrap: on
line diff
--- a/libinterp/corefcn/psi.cc Sun Mar 15 06:30:09 2015 +0000 +++ b/libinterp/corefcn/psi.cc Sun May 03 02:59:28 2015 +0100 @@ -127,16 +127,16 @@ ## Interesting identities of the digamma function, in section of 5.1.3 %!assert (psi (1/3), - em - (3/2) * log(3) - ((sqrt (3) / 6) * pi), eps*10) -%!assert (psi (1/4), - em -3 * log (2) - pi /2, eps*10) +%!assert (psi (1/4), - em -3 * log (2) - pi /2) %!assert (psi (1/6), - em -2 * log (2) - (3/2) * log (3) - ((sqrt (3) / 2) * pi), eps*10) ## First 6 zeros of the digamma function, in section of 5.1.5 (and also on ## Abramowitz and Stegun, page 258, eq 6.3.19) %!assert (psi ( 1.46163214496836234126265954232572132846819620400644), 0, eps) -%!assert (psi (-0.504083008264455409258269304533302498955385182368579), 0, eps*10) +%!assert (psi (-0.504083008264455409258269304533302498955385182368579), 0, eps) %!assert (psi (-1.573498473162390458778286043690434612655040859116846), 0, eps) %!assert (psi (-2.610720868444144650001537715718724207951074010873480), 0, eps*10) -%!assert (psi (-3.635293366436901097839181566946017713948423861193530), 0, eps) +%!assert (psi (-3.635293366436901097839181566946017713948423861193530), 0, eps*10) %!assert (psi (-4.653237761743142441714598151148207363719069416133868), 0, eps*100) ## Tests for complex values @@ -150,10 +150,9 @@ %!assert (imag (psi (i*z)), 1/2 .* 1./z + 1/2 * pi * coth (pi * z), eps *10) ## Abramowitz and Stegun, page 259 eq 6.3.12 -%!assert (imag (psi (1/2 + i*z)), 1/2 * pi * tanh (pi * z), eps*10) +%!assert (imag (psi (1/2 + i*z)), 1/2 * pi * tanh (pi * z), eps) ## Abramowitz and Stegun, page 259 eq 6.3.13 %!assert (imag (psi (1 + i*z)), - 1./(2*z) + 1/2 * pi * coth (pi * z), eps*10) */ -