[R-sig-Geo] spsann 2.0-0 is out (Optimization of Sample Configurations using Spatial Simulated Annealing)

Alessandro Samuel Rosa alessandrosamuel at yahoo.com.br
Tue Mar 15 14:19:16 CET 2016

Dear all,

I'm happy to announce the major CRAN release (2.0-0) of the package spsann. The package provides methods to optimize spatial sample configurations using spatial simulated annealing. Multiple objective functions are implemented for various purposes, such as variogram estimation, spatial trend estimation, and spatial interpolation. A general purpose spatial simulated annealing function enables the user to define his/her own objective function.

The new major release includes several conceptual changes. Despite our efforts, it was not possible to guarantee the compatibility with previous versions. We have decided not to deprecate functions and function arguments because (1) this would require deprecating a lot of code and (2) the user should first read the updated package documentation to understand the conceptual changes that we have made before using the package.
The main changes are:* A completely new annealing schedule was implemented.* A more elegant solution to jitter the sample points was implemented.* Solving multi-objective combinatorial optimization problems has become easier with the creation of a function to compute the Pareto maximum and minimum values.* The output of the optimization is now stored in an object of class OptimizedSampleConfiguration, for which S3 methods were implemented to retrieve information from the new class, as well as producing plots of the optimized sample configuration.* Package documentation was expanded and adapted to cope with the conceptual changes that were made.* Finally, bugs were fixed, warning messages were improved, and a faster code was implemented whenever possible.

With best regards, Alessandro Samuel Rosa
Post-DoctorateQuantitative PedologyUniversidade Federal Rural do Rio de Janeiro

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