[Bug-gsl] [bug #47646] gsl_ran_beta returns NaN for small arguments

[Patrick Alken]

Follow-up Comment #4, bug #47646 (project gsl):

I'm also not sure how to properly test for this case, as the PDF integration
test fails for these small arguments.

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[Bug-gsl] [bug #47646] gsl_ran_beta returns NaN for small arguments

[Patrick Alken]

Update of bug #47646 (project gsl):

  Status:None => Fixed  
 Open/Closed:Open => Closed 

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Follow-up Comment #3:

Patch applied in commit 05c5b5179d5f12e893198e54741cb4b8c289ad09

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Re: [Bug-gsl] [bug #47347] Complex tangent failure for -1000i

[Patrick Alken]

Thanks for your work on this, your patch works very nicely. I've added
it to the git. I'm still working through your other patches.

On 09/11/2016 10:51 PM, Yu Liu wrote:
> Follow-up Comment #1, bug #47347 (project gsl):
>
> Please see test_tan.c for trouble shooting process and gsl_complex_tan.diff
> for a proposed fix.
> 1. This proposed fixed is based on 7141c7adb8100207ef01ff87a94d5179103fcebc
> which add a branch in  gsl_complex_tanh to handle a similar issue. In this
> commit, tanh was modified to have a separate branch to handle large real part
> in input. This is what gsl_complex_tan.diff is doing in essense. In
> test_tan.c, this idea is implemented in `gsl_complex_tan_2` for testing
> purposes.
> 2. glibc implementation
> (https://github.com/lattera/glibc/blob/a2f34833b1042d5d8eeb263b4cf4caaea138c4ad/math/s_ctan.c)
> converts everything to exponential when the imagineary part is big. Is this a
> better implementation?
>
>
>
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Re: [Bug-gsl] gsl_complex_pow() returns unexpected value

[Patrick Alken]

Hello,
 
  I am unable to reproduce the issue - it is working correctly for me
(using the latest version 2.2.1). See below. Can you try using the
latest 2.2.1 and if you still see a problem, please send me an example
program.

$ cat pow.c
#include 
#include 

#include 
#include 
#include 

int
main()
{
  gsl_complex a = gsl_complex_rect(0.0, 9.0);
  gsl_complex b = gsl_complex_rect(2.0, 0.0);
  gsl_complex c = gsl_complex_pow(a, b);

  fprintf(stderr, "c = %.12e + %.12e i\n", GSL_REAL(c), GSL_IMAG(c));

  return 0;
}

$ gcc -g -Wall -o pow pow.c -lm -lgsl -lgslcblas
$ ./pow
c = -8.1000e+01 + 9.919639073094e-15 i

Note that I see the same imaginary part you wrote, except with an
exponent of -15 instead of +15

On 09/05/2016 06:49 AM, David McMackins wrote:
> I'm writing a calculator application which uses the GSL as the backend
> for math operations with complex numbers. When I make a call to
> gsl_complex_pow() with the arguments of 0+9i and 2+0i, I get back
> -81+9.919639073e+15i, instead of just -81+0i as expected.
>
> I'm using libgsl 1.16 as packaged in Debian unstable currently.
>
> Happy Hacking,
>
> David E. McMackins II
> Associate Member, Free Software Foundation (#12889)
>
> www.mcmackins.org www.delwink.com
> www.gnu.org www.fsf.org
>

[Bug-gsl] Bug in Documentation: Golden Ratio

[Schmitz Manuel (LBC)]

Dear Sirs,

there is a typo in the golden ratio constant. Ist must be "0.381...", not 
"0.318..."

Regards,
Manuel

[GNU Scientific Library  Reference Manual Minimization Algorithms  Internet 
Explorer bereitgestellt von LiebherrWerk Biberac]