Re: gamma_inc for octave

[Alexander Hansen]

On 1/9/13 9:20 AM, James Sherman Jr. wrote:
> On Wed, Jan 9, 2013 at 10:49 AM, OYEDAPO OLUFEMI
> <address@hidden> wrote:
>> Hi,
>>
>> Can anyone help me with how to use the upper bound incomplete gamma function
>> "gamma_inc(..)"?. I want to use this function in octave, but it says its not
>> defined. I have installed GSL yet i couldn't get it worked. Any suggestion?
>>
>> J
>>
>>
>>
>> _______________________________________________
>> Help-octave mailing list
>> address@hidden
>> https://mailman.cae.wisc.edu/listinfo/help-octave
>>
> 
> Unless it is just a typo in your email, I think the function you're
> looking for is "gammainc", no underscore in the function name.  At
> least in my octave installation (3.6.0), I get, when looking for the
> gammainc function:
> 
> octave:1> help gammainc
> `gammainc' is a function from the file 
> D:\Octave\Octave3.6.0_gcc4.6.2\lib\octave
> \3.6.0\oct\i686-pc-mingw32\gammainc.oct
> 
>  -- Mapping Function:  gammainc (X, A)
>  -- Mapping Function:  gammainc (X, A, "lower")
>  -- Mapping Function:  gammainc (X, A, "upper")
>      Compute the normalized incomplete gamma function,
> 
> Hope this helps,
> 
> James Sherman
> _______________________________________________
> Help-octave mailing list
> address@hidden
> https://mailman.cae.wisc.edu/listinfo/help-octave
> 

There's a gamma_inc in the gsl package from Octave Forge:

octave:1> help gamma_inc
`gamma_inc' is a function from the file
/sw/lib/octave/3.6.3/packages/gsl-1.0.8/x86_64-apple-darwin-api-v48+/gsl_sf.oct

 -- Loadable Function: Z = gamma_inc (X, Y)
 -- Loadable Function: [Z, ERR] = gamma_inc (...)
     These functions compute the incomplete Gamma Function the
     normalization factor included in the previously defined functions:
     \Gamma(a,x) = \int_x\infty dt t^{a-1} \exp(-t) for a real and x >=
     0.

     ERR contains an estimate of the absolute error in the value Z.

     This function is from the GNU Scientific Library, see
     `http://www.gnu.org/software/gsl/' for documentation.

Is the gsl package loaded?
-- 
Alexander Hansen, Ph.D.
Fink User Liaison
My package updates: http://finkakh.wordpress.com/