Chong Gu chong at
Mon Mar 3 09:52:03 CET 2003

A new version of gss, version 0.8-2, is on CRAN now.  Numerous new
functionalities have been added since my last r-announce post.

An ssanova1 suite has been added since version 0.7-4.  It implements
low-dimensional approximations of the smoothing spline ANOVA models
of the ssanova suite.  ssanova1 scales much better than ssanova with
large sample sizes.

A gssanova1 suite is added for non Gaussian regression.  Similar to
ssanova1, it provides better scalability than gssanova.  Direct
cross-validation is used in gssanova1 instead of the indirect CV of
gssanova.  Currently, only three families are supported: binomial,
poisson, and Gamma; other families of gssanova will be added to
gssanova1 in the (near?) future.

An sshzd suite is added to fit hazard models using right-censored
lifetime data with possible left-truncation and covariates.  It
estimates log hazard as "bivariate" smooth functions of time and
covariates through penalized full likelihood.  It only takes static
covariates but accommodates interactions between time and covariates,
going beyond the proportional hazard models.

Utilities are provided for the calculation of a certain
Kullback-Leibler projection of cross-validated fits to "reduced model"
spaces, for the "testing" of model terms.  Projection code is provide
for ssanova1, gssanova1, ssden, and sshzd fits.

Further details are to be found in the documentations and the examples
therein.  As always, feature suggestions and bug reports will be
sincerely appreciated.

Chong Gu

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