Axel Vogt

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19 years, 101 days
Munich, Bavaria, Germany

MaplePrimes Activity


These are Posts that have been published by Axel Vogt

1/2 hour ago I got from Norton Antivirus:

Besides availability of that forum (our admin would be fired for such) or loading time (quite boaring today) it seems that threads may be  in a strange state, which do not allow them to be viewed. The last time I just ignored that, but as it may be a technical problem here is an example:

http://www.mapleprimes.com/forum/pointinflection

For me it was not possible to opne it by a click yesterday, so tried it at work today and gave up after 5 min (?) waiting on a fast connection. Now at home again the problem persists.

Maple's package DiscreteTransforms is a bit skinny, I miss various ones like discrete cosine transforms (at least the most 4 types), sine transform, Hartley transform, z-transform and may be the fractional Fourier transform or symmetric FTs (not sure for the whole herd).

It should be available, if Maple wants to be a numerical tool for technical users (all kinds of engineering I would say): it would not make sense for them to use other libraries, compile and finally combine with Maple, because it does not have it.

I want to call a GSL function, which writes data to a pointer to be provided
(Regular Spherical Bessel Functions, array version) it has prototype

  int gsl_sf_bessel_jl_steed_array (int lmax, double x, double * jl_x_array)

so the 'array' is a pointer and no specific length (though only lmax + 1 of
the space is used, I think).

I tried the below, but the actual call results in a crash:

  arrB_GSL := define_external(
    'gsl_sf_bessel_jl_steed_array',
   ...
  restart; Digits:=14;     # using Maple 12.02
  J:=Int(arctan(z)^2/(1+4*z^2),z=0..infinity);


  evalf(J);
                           0.40325004753375

  value(J); evalf(%); Re(%);

                ...
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