Link function applied to the association parameter
alpha, which is real
and -1 < alpha < 1.
See Links for more choices.
iapar
Numeric. Optional initial value for alpha.
By default, an initial value is chosen internally.
If a convergence failure occurs try assigning a different value.
Assigning a value will override the argument imethod.
imethod
An integer with value 1 or 2 which
specifies the initialization method. If failure to converge occurs
try the other value, or else specify a value for iapar.
for -1 < alpha < 1.
The support of the function is the unit square.
The marginal distributions are the standard uniform distributions.
When alpha = 0 the random variables are
independent.
This is an Archimedean copula.
Value
An object of class "vglmff" (see vglmff-class).
The object is used by modelling functions such as vglm
and vgam.
Note
The response must be a two-column matrix. Currently, the fitted
value is a matrix with two columns and values equal to 0.5.
This is because each marginal distribution corresponds to a standard
uniform distribution.
Author(s)
T. W. Yee and C. S. Chee
References
Balakrishnan, N. and Lai, C.-D. (2009)
Continuous Bivariate Distributions,
2nd ed.
New York: Springer.