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MIAmaxent

Read our open-access paper introducing MIAmaxent in Ecology and Evolution.

Description

Tools for training, selecting, and evaluating maximum entropy (and standard logistic regression) distribution models. This package provides tools for user-controlled transformation of explanatory variables, selection of variables by nested model comparison, and flexible model evaluation and projection. It follows principles based on the maximum-likelihood interpretation of maximum entropy modeling (Halvorsen et al., 2015), and uses infinitely-weighted logistic regression for model fitting (Fithian & Hastie, 2013).

MIAmaxent is intended primarily for maximum entropy distribution modeling (Phillips et al., 2006; Phillips et al., 2017), and provides an alternative to the standard methodology for training, selecting, and using models. The major advantage in this alternative methodology is greater user control – in variable transformations, in variable selection, and in model output. Comparisons also suggest that this methodology results in simpler models with equally good predictive ability, and reduces the risk of overfitting (Halvorsen et al., 2016).

The predecessor to this package is the MIA Toolbox, which is described in detail in Mazzoni et al. (2015).

Installation

Install the release version from CRAN:

install.packages("MIAmaxent")

Or the development version from GitHub:

# install.packages(c("remotes", "R.rsp"))
remotes::install_github("julienvollering/MIAmaxent", build_vignettes = TRUE)

User Workflow

This diagram outlines a common workflow for users of this package. Functions are shown in red.

References

Fithian, W., & Hastie, T. (2013). Finite-sample equivalence in statistical models for presence-only data. The annals of applied statistics, 7(4), 1917.

Halvorsen, R., Mazzoni, S., Bryn, A. & Bakkestuen, V. (2015) Opportunities for improved distribution modelling practice via a strict maximum likelihood interpretation of MaxEnt. Ecography, 38, 172-183.

Halvorsen, R., Mazzoni, S., Dirksen, J.W., Næsset, E., Gobakken, T. & Ohlson, M. (2016) How important are choice of model selection method and spatial autocorrelation of presence data for distribution modelling by MaxEnt? Ecological Modelling, 328, 108-118.

Mazzoni, S., Halvorsen, R. & Bakkestuen, V. (2015) MIAT: Modular R-wrappers for flexible implementation of MaxEnt distribution modelling. Ecological Informatics, 30, 215-221.

Phillips, S.J., Anderson, R.P., Dudík, M., Schapire, R.E., & Blair, M.E. (2017). Opening the black box: an open‐source release of Maxent. Ecography, 40(7), 887-893.

Phillips, S.J., Anderson, R.P. & Schapire, R.E. (2006) Maximum entropy modeling of species geographic distributions. Ecological Modelling, 190, 231-259.

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Version

Install

install.packages('MIAmaxent')

Monthly Downloads

560

Version

1.4.0

License

MIT + file LICENSE

Issues

Pull Requests

Stars

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Maintainer

Julien Vollering

Last Published

October 18th, 2025

Functions in MIAmaxent (1.4.0)

selectEV

Select parsimonious set of explanatory variables.
toydata_sp1po

Occurrence and environmental toy data.
deriveVars

Derive variables by transformation.
projectModel

Project model across explanatory data.
plotFOP

Plot Frequency of Observed Presence (FOP).
chooseModel

Trains a model containing the explanatory variables specified.
readData

Read in data object from files.
plotResp

Plot model response.
predict.MIAmaxent_iwlr

Predict method for infinitely-weighted logistic regression
calculateRVA

Calculates variable contributions as RVA
testAUC

Calculate model AUC with test data.
selectDVforEV

Select parsimonious sets of derived variables.
toydata_dvs

Derived variables and transformation functions, from toy data.
MIAmaxent-package

MIAmaxent: A Modular, Integrated Approach to Maximum Entropy Distribution Modeling
toydata_seldvs

Selected derived variables accompanied by selection trails, from toy data.
toydata_selevs

Selected explanatory variables accompanied by selection trails, from toy data.
modelFromLambdas

Maxent model from .lambdas file.