Dear S-Plus community,
I need some advice on the use of link functions in GAMs. I am trying to model
dispersal distances (in meters). The data distribution has a high peak at low
numbers and then tapers off at high numbers.
What are is the procedure to choose the best link and variance functions for
such data? Do I need to stick to canonical link functions and if not, then how
can I know if certain combinations of link functions and variances actually
mean something biologically? For example, my data seem well modelled using
family=quasi, link=log, variance="mu^2". Does this estimate a certain
distribution that has a name? Do I need to try every combinations of link and
variance?
I am using S-Plus 4.5 Professional Edition, release 2, on Windows 95.
Thanks for your help,
Marc-André Villard
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