Re: [boost] wrong result in complex pow

31 Jan 2021

      Hello Christopher,
I just noticed that my simple patch with base=0 doesn't work. It is probably not that simple.
https://godbolt.org/z/8Me15Y

regards
Gero

Am 30.01.21 um 16:22 schrieb Christopher Kormanyos:
...
...
...
 the pow-function pow(scalar, complex) in
boost/math/cstdfloat/cstdfloat_complex_std.hpp
get wrong result.
...
Thanks Gero,
I am on the go, but later today, I'll add this
as an issue in Git and kick off the discussion
for the fix with the colleagues.
A new issue can be found here, but it
is not clear which code example elicits
the unexpected behavior.
https://github.com/boostorg/math/issues/506 https://github.com/boostorg/math/issues/506
On Thursday, January 28, 2021, 12:55:59 PM GMT+1, Gero Peterhoff via Boost  wrote:
Hello,
the pow-function pow(scalar, complex) in boost/math/cstdfloat/cstdfloat_complex_std.hpp get wrong result.
Current implementation:
inline complex pow(const BOOST_CSTDFLOAT_EXTENDED_COMPLEX_FLOAT_TYPE& x,
                                                                const complex& a)
{
  return std::exp(a * std::log(x));
}
I think that's correct:
inline complex pow(const BOOST_CSTDFLOAT_EXTENDED_COMPLEX_FLOAT_TYPE& x,
                                                                const complex& a)
{
  return std::exp(a * std::log(complex(x)));
}
regards
Gero
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