Last data update: 2014.03.03
R: Model Predictions for a Linear Model
predict20x R Documentation
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.)
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.
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 T, print out the prediction matrix.
...
optional arguments that are passed to the generic "predict"
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.
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)
Results