Logical.
If log = TRUE then the logarithm of the density is returned.
Author
T. W. Yee
Details
See genbetaII, which is the VGAM family function
for estimating the parameters by maximum likelihood estimation.
Several distributions, such as the Singh-Maddala, are special case of
this flexible 4-parameter distribution.
The product of shape1.a and shape2.p determines the
behaviour of the density at the origin.
References
Kleiber, C. and Kotz, S. (2003).
Statistical Size Distributions in Economics and
Actuarial Sciences,
Hoboken, NJ, USA: Wiley-Interscience.