VGAM: model.framevlm – R documentation

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model.framevlm

Construct the Model Frame of a VLM Object

Description

This function returns a data.frame with the variables. It is applied to an object which inherits from class "vlm" (e.g., a fitted model of class "vglm").

Usage

model.framevlm(object, setupsmart = TRUE, wrapupsmart = TRUE, ...)

Arguments

`object`	a model object from the VGAM R package that inherits from a vector linear model (VLM), e.g., a model of class `"vglm"`.
`...`	further arguments such as `data`, `na.action`, `subset`. See `model.frame` for more information on these.
`setupsmart, wrapupsmart`	Logical. Arguments to determine whether to use smart prediction.

Details

Since object is an object which inherits from class "vlm" (e.g., a fitted model of class "vglm"), the method will either returned the saved model frame used when fitting the model (if any, selected by argument model = TRUE) or pass the call used when fitting on to the default method.

This code implements smart prediction (see smartpred).

Value

A data.frame containing the variables used in the object plus those specified in ....

References

Chambers, J. M. (1992). Data for models. Chapter 3 of Statistical Models in S eds J. M. Chambers and T. J. Hastie, Wadsworth & Brooks/Cole.

Examples

# Illustrates smart prediction
pneumo <- transform(pneumo, let = log(exposure.time))
fit <- vglm(cbind(normal,mild, severe) ~ poly(c(scale(let)), 2),
            multinomial, data = pneumo, trace = TRUE, x = FALSE)
class(fit)

check1 <- head(model.frame(fit))
check1
check2 <- model.frame(fit, data = head(pneumo))
check2
all.equal(unlist(check1), unlist(check2))  # Should be TRUE

q0 <- head(predict(fit))
q1 <- head(predict(fit, newdata = pneumo))
q2 <- predict(fit, newdata = head(pneumo))
all.equal(q0, q1)  # Should be TRUE
all.equal(q1, q2)  # Should be TRUE

VGAM

Vector Generalized Linear and Additive Models

v1.1-5

GPL-3

Authors

Thomas Yee [aut, cre], Cleve Moler [ctb] (author of several LINPACK routines)

Initial release

2021-01-13