voi: a generic package to calculate the expected value of information

A common interface for several methods to calculate the
- Expected Value of (Partial) Perfect Information and the
- Expected Value of Sample Information
A project of the ConVOI Group: the Collaborative Network for Value of Information

Comparison with other packages

voi is pure "command-based" R, with no web interface like SAVI.

The R commands in voi are clean and consistent: they all have the same basic interface, so you can switch between computational methods easily.
Outputs are all in "tidy" data frames for consistency, and to facilitate post-processing and plotting with modern tools such as ggplot2.

voi includes all the EVPPI computation methods that are in SAVI (GAM and Gaussian process regression), and includes the INLA method from BCEA.
Some other nonparametric regression methods ("earth", "bart") are included in voi, which may improve efficiency for multiparameter EVPPI computation problems with large numbers of parameters.

voi is the first package to implement a range of EVSI computation methods: nonparametric regression, moment matching and importance sampling. A simple model for the expected net benefit of sampling is also included.

voi will not benefit you if you want a web interface, or if you just need single-parameter EVPPI and are happy with SAVI/BCEA.
voi will benefit you if you want to calculate EVSI, or multiparameter EVPPI with large numbers of parameters.

Stable version

install.packages("voi")

Development version

remotes::install_github("chjackson/voi")