qgcomp (version 2.15.2)

predict.qgcompfit: Default prediction method for a qgcompfit object (non-survival outcomes only)

Description

get predicted values from a qgcompfit object, or make predictions in a new set of data based on the qgcompfit object. Note that when making predictions from an object from qgcomp.glm.boot, the predictions are made from the (conditional) g-computation model rather than the marginal structural model. Predictions from the marginal structural model can be obtained via msm.predict. Note that this function accepts non-quantized exposures in "newdata" and automatically quantizes them according to the quantile cutpoints in the original fit.

Usage

# S3 method for qgcompfit
predict(object, expnms = NULL, newdata = NULL, type = "response", ...)

Arguments

object

"qgcompfit" object from qgcomp.glm.noboot, qgcomp.glm.boot, qgcomp.zi.noboot, or qgcomp.zi.bootfunctions

expnms

character vector of exposures of interest

newdata

(optional) new set of data with all predictors from "qgcompfit" object

type

(from predict.glm) the type of prediction required. The default is on the scale of the linear predictors; the alternative "response" is on the scale of the response variable. Thus for a default binomial model the default predictions are of log-odds (probabilities on logit scale) and type = "response" gives the predicted probabilities. The "terms" option returns a matrix giving the fitted values of each term in the model formula on the linear predictor scale.

...

arguments to predict.glm

Examples

set.seed(50)
dat <- data.frame(y=runif(50), x1=runif(50), x2=runif(50), z=runif(50))
obj1 <- qgcomp.glm.noboot(y ~ z + x1 + x2, expnms = c('x1', 'x2'), data=dat, q=2)
obj2 <- qgcomp.glm.boot(y ~ z + x1 + x2, expnms = c('x1', 'x2'), data=dat, q=2, B=10, seed=125)
set.seed(52)
dat2 <- data.frame(y=runif(50), x1=runif(50), x2=runif(50), z=runif(50))
summary(predict(obj1, expnms = c('x1', 'x2'), newdata=dat2))
summary(predict(obj2, expnms = c('x1', 'x2'), newdata=dat2))