predict20x: Model Predictions for a Linear Model

In s20x: Functions for University of Auckland Course STATS 201/208 Data Analysis

Model Predictions for a Linear Model

Description

Uses the main output and some error messages from R function 'predict' but gives you more output. (Error messages are not reliable when used in Splus.)

Usage

predict20x(object, newdata, cilevel = 0.95, digit = 3, print.out = TRUE, ...)

Arguments

object	an lm object, i.e. the output from lm.
newdata	prediction data frame.
cilevel	confidence level of the interval.
digit	decimal numbers after the point.
print.out	if TRUE, print out the prediction matrix.
...	optional arguments that are passed to the generic 'predict'

Details

Note: The data frame, newdata, must have the same column order and data types (e.g. numeric or factor) as those used in fitting the model.

Value

frame	vector or matrix including predicted values, confidence intervals and predicted intervals.
fit	prediction values.
se.fit	standard error of predictions.
residual.scale	residual standard deviations.
df	degrees of freedom for residual.
cilevel	confidence level of the interval.

Note

This function is deprecated. It will be removed in future versions of the package.

this function is deprecated as it is never used in class any more. We prefer the standard predict method.

See Also

predict, predict.lm, as.data.frame.

Examples

# Zoo data
data(zoo.df)
zoo.df = within(zoo.df, {day.type = factor(day.type)})
zoo.fit = lm(log(attendance) ~ time + sun.yesterday + nice.day + day.type + tv.ads,
             data = zoo.df)
pred.zoo = data.frame(time = 8, sun.yesterday = 10.8, nice.day = 0,
                      day.type = factor(3), tv.ads = 1.181)
predict20x(zoo.fit, pred.zoo)

# Peruvian Indians data
data(peru.df)
peru.fit = lm(BP ~ age + years + I(years^2) + weight + height, data = peru.df)
pred.peru = data.frame(age = 21, years = 2, `I(years^2)` = 2, weight = 71, height = 1629)
predict20x(peru.fit, pred.peru)

s20x documentation built on Aug. 21, 2023, 5:07 p.m.