R help - May 2011 - dbetagen function in mc2d package

Hi all,
I found this useful package for generalized beta, yet the function that
calculates its density leaves me puzzled, especially when I plotted it:

plot(function(y) dbetagen(y,4,1.2,min=0,max=40),xlim=c(0,40))

The area between the density curve and the x axis does not seem to measure
1!!!

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krusty the klown <alessandrobarbiero <at> libero.it> writes:
> I found this useful package for generalized beta, yet the function that
> calculates its density leaves me puzzled, especially when I plotted it:
> 
> plot(function(y) dbetagen(y,4,1.2,min=0,max=40),xlim=c(0,40))
> 
> The area between the density curve and the x axis does not seem to measure
> 1!!!
  It would help to tell us that this is in the "mc2d" package ...
> integrate(dbetagen,shape1=4,shape2=1.2,min=0,max=40,0,40)
40 with absolute error < 2e-06

  I would suggest that you report this as a bug to the
package maintainers [maintainer("mc2d")].  Seems fairly easy to 
fix for yourself, though -- just scale by the size of the domain (max-min).


  Ben Bolker