cgam1.29 package

Constrained Generalized Additive Model

best.fit

Extract the Best Fit Returned by the ShapeSelect Routine

cgam

Constrained Generalized Additive Model Fitting

cgamm

Constrained Generalized Additive Mixed-Effects Model Fitting

conc

Specify a Concave Shape-Restriction in a CGAM Formula

conv

Specify a Convex Shape-Restriction in a CGAM Formula

decr.conc

Specify a Decreasing and Concave Shape-Restriction in a CGAM Formula

decr.conv

Specify a Decreasing and Convex Shape-Restriction in a CGAM Formula

decr

Specify a Decreasing Shape-Restriction in a CGAM Formula

in.or.out

To Include a Non-Parametrically Modelled Predictor in a SHAPESELECT Fo...

incr.conc

Specify an Increasing and Concave Shape-Restriction in a CGAM Formula

incr.conv

Specify an Increasing and Convex Shape-Restriction in a CGAM Formula

incr

Specify an Increasing Shape-Restriction in a CGAM Formula

Ord

Specify an Ordered Categorical Family in a CGAM Formula

plotpersp_control

Control Parameters for plotpersp.cgam

plotpersp

Create a 3D Plot for a CGAM Object

predict.cgam

Predict Method for CGAM Fits

s.conc.conc

Specify a Doubly-Concave Shape-Restriction in a CGAM Formula

s.conc

Specify a Smooth and Concave Shape-Restriction in a CGAM Formula

s.conv.conv

Specify a Doubly-convex Shape-Restriction in a CGAM Formula

s.conv

Specify a Smooth and Convex Shape-Restriction in a CGAM Formula

s.decr.conc

Specify a Smooth, Decreasing and Concave Shape-Restriction in a CGAM F...

s.decr.conv

Specify a Smooth, Decreasing and Convex Shape-Restriction in a CGAM Fo...

s.decr.decr

Specify a Doubly-Decreasing Shape-Restriction in a CGAM Formula

s.decr.incr

Specify a Decreasing-Increasing Shape-Restriction in a CGAM Formula

s.decr

Specify a Smooth and Decreasing Shape-Restriction in a CGAM Formula

s.incr.conc

Specify a Smooth, Increasing and Concave Shape-Restriction in a CGAM F...

s.incr.conv

Specify an Smooth, Increasing and Convex Shape-Restriction in a CGAM F...

s.incr.decr

Specify an Increasing-Decreasing Shape-Restriction in a CGAM Formula

s.incr.incr

Specify a Doubly-Increasing Shape-Restriction in a CGAM Formula

s.incr

Specify a Smooth and Increasing Shape-Restriction in a CGAM Formula

s

Specify a Smooth Shape-Restriction in a CGAM Formula

shapes

To Include a Non-Parametrically Modelled Predictor in a SHAPESELECT Fo...

ShapeSelect

Variable and Shape Selection via Genetic Algorithm

testpar

Parametric Monotone/Quadratic vs Smooth Constrained Test

tree

Specify a Tree-Ordering in a CGAM Formula

umbrella

Specify an Umbrella-Ordering in a CGAM Formula

A constrained generalized additive model is fitted by the cgam routine. Given a set of predictors, each of which may have a shape or order restrictions, the maximum likelihood estimator for the constrained generalized additive model is found using an iteratively re-weighted cone projection algorithm. The ShapeSelect routine chooses a subset of predictor variables and describes the component relationships with the response. For each predictor, the user needs only specify a set of possible shape or order restrictions. A model selection method chooses the shapes and orderings of the relationships as well as the variables. The cone information criterion (CIC) is used to select the best combination of variables and shapes. A genetic algorithm may be used when the set of possible models is large. In addition, the cgam routine implements a two-dimensional isotonic regression using warped-plane splines without additivity assumptions. It can also fit a convex or concave regression surface with triangle splines without additivity assumptions. See Liao X, Meyer MC (2019)<doi:10.18637/jss.v089.i05> for more details.

  • Maintainer: Xiyue Liao
  • License: GPL (>= 2)
  • Last published: 2025-08-23