derived | R Documentation |
Raw data on blood pressure, body mass and age on 44 female patients, and covariance matrix for derived variables.
data(derived)
A list containing a dataframe
raw
with 44 lines and 5 columns and a
symmetric 4x4 covariance matrix S
.
The following is the description of the variables
in the dataframe raw
Sys
Systolic blood pressure, in mm Hg
Dia
Diastolic blood pressure, in mm Hg
Age
Age of the patient, in years
Hei
Height, in cm
Wei
Weight, in kg
The following is the description of the variables
for the covariance matrix S
.
Y
Derived variable Y=log(Sys/Dia)
X
Derived variables X=log(Dia)
Z
Body mass index Z=Wei/(Hei/100)^2
W
Age
Wermuth N. and Cox D.R. (1995). Derived variables calculated from similar joint responses: some characteristics and examples. Computational Statistics and Data Analysis, 19, 223-234.
# A DAG model with a latent variable U
G = DAG(Y ~ Z + U, X ~ U + W, Z ~ W)
data(derived)
# The model fitted using the derived variables
out = fitDagLatent(G, derived$S, n = 44, latent = "U")
# An ancestral graph model marginalizing over U
H = AG(G, M = "U")
# The ancestral graph model fitted obtaining the
# same result
out2 = fitAncestralGraph(H, derived$S, n = 44)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.