[Bug-gsl] [bug #41759] DHT manual

[Patrick Alken]

URL:
  <http://savannah.gnu.org/bugs/?41759>

                 Summary: DHT manual
                 Project: GNU Scientific Library
            Submitted by: psa
            Submitted on: Mon 03 Mar 2014 01:08:19 AM GMT
                Category: Documentation
                Severity: 3 - Normal
        Operating System: 
                  Status: None
             Assigned to: None
             Open/Closed: Open
                 Release: 
         Discussion Lock: Any

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Details:

Dear GSL-manual team,

the manual for the DHT should be updated:

when the scaling factor X is used,
the factor X^2 enters the calculation.
Then, DHT[f](k) calculates
1/(2Pi) int f(x) e^(-i x k) d^2x
for a two dimensional x.
This is not clear mentioned in the documentation.

Moreover, when using the factor X, after a forward and backward 
transformation there enters the factor j_{nu,i}^2 / X^4, NOT only 
j_{nu,i}^2.

This can easily be seen from the article of H.F. Johnson (mentioned in 
the documentation), eq. (13), where DHT calculates always a term as 
given by eq. (12), for forward and backward transform, respectively.

It took me some time to find this out, so it would be nice to update the 
documentation with respect to future readership.
I am willing to help you, if it is not delayed by monthes.

A.Hartel =at= uu.nl




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