Description Usage Format Source References See Also Examples
The Birthwt
data contains 189 observations, 16 predictors, and
an outcome, birthweight, available both as a continuous measure and a
binary indicator for low birth weight. The data were
collected at Baystate Medical Center, Springfield, Mass during 1986.
This data frame is a reparameterization of the birthwt
data
frame from the MASS
package.
1 |
The Birthwt
object is a list containing four elements:
bwt
:Birth weight in kilograms
low
:Indicator of birth weight less than 2.5kg
X
:Matrix of predictors
group
:Vector describing how the columns of X are
grouped
The matrix X
contains the following columns:
age1,age2,age3
:Orthogonal polynomials of
first, second, and third degree representing mother's age in
years
lwt1,lwt2,lwt3
:Orthogonal polynomials of
first, second, and third degree representing mother's weight in
pounds at last menstrual period
white,black
:Indicator functions for mother's race;
"other" is reference group
smoke
:Smoking status during pregnancy
ptl1,ptl2m
:Indicator functions for one or for two or
more previous premature labors, respectively. No previous
premature labors is the reference category.
ht
:History of hypertension
ui
:Presence of uterine irritability
ftv1,ftv2,ftv3m
:Indicator functions for
one, for two, or for three or more physician visits during the
first trimester, respectively. No visits is the reference
category.
MASS
. R
package.
https://cran.r-project.org/package=MASS
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.
Hosmer, D.W. and Lemeshow, S. (1989) Applied Logistic Regression. New York: Wiley
1 2 3 4 5 6 7 |
0 1
130 59
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.