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gamma pdf

In the gampdf function, the parameter A and B stad for mean and standard deviation, right?? is there any way to use as input the alpha and beta values of my gamma distribution?? or do I need to compute the mean and stdev previously in my code???

Thaks 
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9/18/2008 8:17:02 AM
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Hi,
A and B are not mean and stdv,but the scale and shape parameters of the gamma distribution.If you know the parameters of your gamma distribution (normally alfa is the shape parameter A and beta is 1/B,B the scale parameter...but you may have a different nomenclature),you can use them directly with the gampdf to compute the probability density function.

"Rogelio " <rogelio.a.mancisidor@student.bi.no> wrote in message <gat2pt$no9$1@fred.mathworks.com>...
> In the gampdf function, the parameter A and B stad for mean and standard deviation, right?? is there any way to use as input the alpha and beta values of my gamma distribution?? or do I need to compute the mean and stdev previously in my code???
> 
> Thaks 
0
9/18/2008 10:45:03 AM
Thanks mate! I was suspecting that the way I was settig my parameters were wrong. First I tried directly alpha and beta, then mean and std but still didnt get what I was hoping for.

"Lorenzo Guerrasio" <lorenzo.guerrasio@email.it> wrote in message <gatbff$ng5$1@fred.mathworks.com>...
> Hi,
> A and B are not mean and stdv,but the scale and shape parameters of the gamma distribution.If you know the parameters of your gamma distribution (normally alfa is the shape parameter A and beta is 1/B,B the scale parameter...but you may have a different nomenclature),you can use them directly with the gampdf to compute the probability density function.
> 
> "Rogelio " <rogelio.a.mancisidor@student.bi.no> wrote in message <gat2pt$no9$1@fred.mathworks.com>...
> > In the gampdf function, the parameter A and B stad for mean and standard deviation, right?? is there any way to use as input the alpha and beta values of my gamma distribution?? or do I need to compute the mean and stdev previously in my code???
> > 
> > Thaks 
0
9/18/2008 2:14:04 PM
Lorenzo Guerrasio wrote:
> Hi,
> A and B are not mean and stdv,but the scale and shape parameters of the gamma distribution.If you know the parameters of your gamma distribution (normally alfa is the shape parameter A and beta is 1/B,B the scale parameter...but you may have a different nomenclature),you can use them directly with the gampdf to compute the probability density function.

And you can use them in the GAMSTAT function to compute the mean and the variance.
0
9/18/2008 2:18:08 PM
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