The hospital manpower data, taken from Myers (1990), table 3.8,
are a well-known example of highly collinear data to which
ridge regression and various shrinkage and selection methods
are often applied.
The data consist of measures taken at 17 U.S. Naval Hospitals
and the goal is to predict the required monthly man hours
for staffing purposes.
Usage
data(Manpower)
Format
A data frame with 17 observations on the following 6 variables.
Hours
monthly man hours (response variable)
Load
average daily patient load
Xray
monthly X-ray exposures
BedDays
monthly occupied bed days
AreaPop
eligible population in the area in thousands
Stay
average length of patient's stay in days
Details
Myers (1990) indicates his source was
"Procedures and Analysis for Staffing Standards Development: Data/Regression Analysis Handbook",
Navy Manpower and Material Analysis Center, San Diego, 1979.
Source
Raymond H. Myers (1990). Classical and Modern Regression with Applications, 2nd ed.,
PWS-Kent, pp. 130-133.
References
Donald R. Jensen and Donald E. Ramirez (2012).
Variations on Ridge Traces in Regression,
Communications in Statistics - Simulation and Computation,
41 (2), 265-278.
See Also
manpower for the same data, and other analyses
Examples
data(Manpower)
mmod <- lm(Hours ~ ., data=Manpower)
vif(mmod)
# ridge regression models, specified in terms of equivalent df
mridge <- ridge(Hours ~ ., data=Manpower, df=seq(5, 3.75, -.25))
vif(mridge)
# univariate ridge trace plots
traceplot(mridge)
traceplot(mridge, X="df")
# bivariate ridge trace plots
plot(mridge, radius=0.25, labels=mridge$df)
pairs(mridge, radius=0.25)
# 3D views
# ellipsoids for Load, Xray & BedDays are nearly 2D
plot3d(mridge, radius=0.2, labels=mridge$df)
# variables in model selected by AIC & BIC
plot3d(mridge, variables=c(2,3,5), radius=0.2, labels=mridge$df)
# plots in PCA/SVD space
mpridge <- pca.ridge(mridge)
traceplot(mpridge, X="df")
biplot(mpridge, radius=0.25)