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mgcv (version 1.9-5)

Mixed GAM Computation Vehicle with Automatic Smoothness Estimation

Description

Generalized additive (mixed) models, some of their extensions and other generalized ridge regression with multiple smoothing parameter estimation by (Restricted) Marginal Likelihood, Cross Validation and similar, or using iterated nested Laplace approximation for fully Bayesian inference. See Wood (2025) for an overview. Includes a gam() function, a wide variety of smoothers, 'JAGS' support and distributions beyond the exponential family.

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Version

Install

install.packages('mgcv')

Monthly Downloads

79,893

Version

1.9-5

License

GPL (>= 2)

Maintainer

Simon Wood

Last Published

November 2nd, 2026

Functions in mgcv (1.9-5)

Censored Box-Cox Gaussian family

bug.reports.mgcv

Reporting mgcv bugs.

Evaluate cyclic B spline basis

Internal functions for discretized model matrix handling

Update a strictly additive bam model for new data.

GAM Tweedie families

Generalized additive models for very large datasets

blas.thread.test

BLAS thread safety

Cholesky decomposition of a band diagonal matrix

Approximate hypothesis tests related to GAM fits

Additive Cox proportional hazard models with time varying covariates

Reduced version of Columbus OH crime data

GAM concurvity measures

Obtaining derivative w.r.t. linear predictor

Basis dimension choice for smooths

Additive Cox Proportional Hazard Model

GAM censored Poisson family

Deletion and rank one Cholesky factor update

GAM censored normal family for log-normal AFT and Tobit models

GAM censored logistic distribution family for log-logistic AFT models

Factor smooth interactions in GAMs

Distribution families in mgcv

Detect linear dependencies of one matrix on another

Stable evaluation of difference between Poisson c.d.f.s

Form component of GAMM covariance matrix

Stable evaluation of difference between normal c.d.f.s

fix.family.link

Modify families for use in GAM fitting and checking

extract.lme.cov

Extract the data covariance matrix from an lme object

exclude.too.far

Exclude prediction grid points too far from data

Some diagnostics for a fitted gam model

gam.fit5.post.proc

Post-processing output of gam.fit5

Specifying generalized additive models

gam.convergence

GAM convergence and performance issues

Generalized additive models with integrated smoothness estimation

P-IRLS GAM estimation with GCV, UBRE/AIC or RE/ML derivative calculation

FELSPLINE test function

Setting GAM fitting defaults

GAM P-IRLS estimation with GCV/UBRE smoothness estimation (deprecated)

Simple posterior simulation with gam fits

Minimize GCV or UBRE score of a GAM using `outer' iteration

Finding stable orthogonal re-parameterization of the square root penalty.

Transform derivatives wrt mu to derivatives wrt linear predictor

Identifiability side conditions for a GAM

Generalized Additive Model Selection

Report gam smoothness estimates as variance components

Objective functions for GAM smoothing parameter estimation

Scale parameter estimation in GAMs

Fitted gam object

Simulate example data for GAMs

Generalized Extreme Value location-scale model family

identifiability

Identifiability constraints

Grouped families

Calculating derivatives of log-likelihood wrt regression coefficients

GAM Integrated Nested Laplace Approximation Newton Enhanced

Get named variable or evaluate expression from list or data.frame

Gaussian location-scale model family

Getting log generalized determinant of penalty matrices

Gamma location-scale model family

Gumbel location-scale model family

Log Tweedie density evaluation

Extract the diagonal of the influence/hat matrix for a GAM

Generalized Additive Mixed Models

Just Another Gibbs Additive Modeller: JAGS support for mgcv.

Starting values for multiple smoothing parameter estimation

Which of a set of points lie within a polygon defined region

Are points inside boundary?

Checking smooth basis dimension

linear.functional.terms

Linear functionals of a smooth in GAMs

Interpret a GAM formula

Size of list elements

Obtain square roots of penalty matrices

Sparse chol function

magic.post.proc

Auxilliary information from magic fit

Parallel computation in mgcv.

AIC and Log likelihood for a fitted GAM

Stable Multiple Smoothing Parameter Estimation by GCV or UBRE

Basic linear programming

Missing data in GAMs

Obtain a name for a new variable that is not already in use

Multivariate normal additive models

Frequently Asked Questions for package mgcv

Alternative to log parameterization for variance components

Monotonicity constraints for a cubic regression spline

Mixed GAM Computation Vehicle with GCV/AIC/REML/NCV smoothness estimation and GAMMs by REML/PQL

Smallest square root of matrix

model.matrix.gam

Extract model matrix from GAM fit

Functions for better-than-log positive parameterization

GAM multinomial logistic regression

GAM negative binomial families

GAM ordered categorical family

Overflow proof pdMat class for multiples of the identity matrix

Default GAM plotting

Options in mgcv

Automatically place a set of knots evenly through covariate values

null.space.dimension

The basis of the space of un-penalized functions for a TPRS

The one standard error rule for smoother models

Extract the effective degrees of freedom associated with each penalty in a gam fit

Functions implementing a pdMat class for tensor product smooths

Penalized Constrained Least Squares Fitting

Generate Tweedie random deviates

Plot geographic regions defined as polygons

Generalized Additive Model residuals

Generate inverse Gaussian random deviates

Random effects in GAMs

Print a Generalized Additive Model object.

Prediction from fitted GAM model

Evaluate the c.d.f. of a weighted sum of chi-squared deviates

QQ plots for gam model residuals

Prediction from fitted Big Additive Model model

Sinh-arcsinh location scale and shape model family

Shape constrained additive smooth models

Extract or modify diagonals of a matrix

Generate from or evaluate multivariate normal or t densities.

set.mgcv.options

Set mgcv options

Defining smooths in GAM formulae

Compute truncated eigen decomposition of a symmetric matrix

Single index models with mgcv

smooth.construct

Constructor functions for smooth terms in a GAM

GAM scaled t family for heavy tailed data

smooth.construct.mrf.smooth.spec

Markov Random Field Smooths

smooth.construct.gp.smooth.spec

Low rank Gaussian process smooths

smooth.construct.ps.smooth.spec

P-splines in GAMs

smooth.construct.fs.smooth.spec

Factor smooth interactions in GAMs

smooth.construct.bt.smooth.spec

B-spline tensor product smooths with general penalties

smooth.construct.bs.smooth.spec

Penalized B-splines in GAMs

smooth.construct.cr.smooth.spec

Penalized Cubic regression splines in GAMs

smooth.construct.re.smooth.spec

Simple random effects in GAMs

smooth.construct.ds.smooth.spec

Low rank Duchon 1977 splines

smooth.construct.ad.smooth.spec

Adaptive smooths in GAMs

Generic function to provide extra information about smooth specification

smooth.construct.sos.smooth.spec

Splines on the sphere

smooth.construct.t2.smooth.spec

Tensor product smoothing constructor

Smooth terms in GAM

smooth.construct.tensor.smooth.spec

Tensor product smoothing constructor

smooth.construct.so.smooth.spec

Soap film smoother constructer

smooth.construct.sz.smooth.spec

Constrained factor smooth interactions in GAMs

Prediction/Construction wrapper functions for GAM smooth terms

Convert a smooth to a form suitable for estimating as random effect

smooth.construct.tp.smooth.spec

Penalized thin plate regression splines in GAMs

Extract smoothing parameter estimator covariance matrix from (RE)ML GAM fit

trind.generator

Generates index arrays for upper triangular storage

totalPenaltySpace

Obtaining (orthogonal) basis for null space and range of the penalty matrix

Alternatives to step.gam

spasm.construct

Experimental sparse smoothers

Choleski decomposition of a tri-diagonal matrix

tensor.prod.model.matrix

Row Kronecker product/ tensor product smooth construction

Summary for a GAM fit

Define alternative tensor product smooths in GAM formulae

Define tensor product smooths or tensor product interactions in GAM formulae

Visualization of GAM objects

find the unique rows in a matrix

Zero inflated (hurdle) Poisson location-scale model family

GAM zero-inflated (hurdle) Poisson regression family

Tweedie location scale family

Extract parameter (estimator) covariance matrix from GAM fit

Applying re-parameterization from log-determinant of penalty matrix to model matrix.

Predict.matrix.cr.smooth

Predict matrix method functions

Re-parametrizing model matrix X

Setting up a list representing a block diagonal penalty matrix

Neighbourhood Cross Validation

Find rank of upper triangular matrix

Level 5 fractional factorial designs

Predict.matrix.soap.film

Prediction matrix for soap film smooth

Prediction methods for smooth terms in a GAM

GAM beta regression family