Xpose is an S-PLUS based model building aid for population
analysis using NONMEM. It facilitates data set checkout, exploration
and visualization, model diagnostics, candidate covariate
identification and model comparison:
* Data set checkout includes visualization of the observed
variable(s), covariates and plots to reveal errors in the
data file.
* Model diagnostic plots includes the usual residual plots
but also plots to check the validity of assumptions specific
to non-linear mixed effects models.
* Data exploration is also done by various plots but also
includes auxiliary screening analyses such as stepwise generalized
additive modeling (GAM) and tree based modeling.
* The stability of the GAM results with respect to covariate
model selection as well as the impact of influential individuals
and certain types of covariate interactions can be explored
using a bootstrap re-sampling procedure.
* To facilitate documentation, Xpose can produce run summaries
and run records. The run records are one page summaries of
a run consisting of a combination of goodness of fit plots,
parameter estimates and the model file. Run records are tabulated
summaries of many runs consisting of user comments, termination
messages and objective function values.
Changes in latest Xpose 3 versions:
Xpose 3.010 -> Xpose 3.011
* Fixed the "quit-problem".
Xpose 3.009 -> Xpose 3.010
* All PRED vs DV plots are changed to DV vs PRED, which is
actually the right way of drawing these graphs!
* Run records can now be exported as HTML-tables that can
be directly imported into MS Word.
* Changed the contents of the distribution a bit.
* Minor bugfixes. Put back one of the functions that creates
a time after dose data item (it disappeared between 3.008
and 3.009).
Reference:
E. N. Jonsson and M. O. Karlsson - "Xpose - an S-PLUS based
population pharmacokinetic/pharmacodynamic model building
aid for NONMEM", Comp Meth Prog Biomed 58 (1999), pp: 51-64.
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