summary.optweight | R Documentation |
These functions summarize the weights resulting from a call to
optweight()
or optweight.svy()
. summary()
produces summary statistics on the distribution of weights, including their
range and variability, and the effective sample size of the weighted sample
(computing using the formula in McCaffrey, Rudgeway, & Morral, 2004). plot()
creates a histogram of the weights.
## S3 method for class 'optweight'
summary(object, top = 5, ignore.s.weights = FALSE, weight.range = TRUE, ...)
## S3 method for class 'optweightMV'
summary(object, top = 5, ignore.s.weights = FALSE, weight.range = TRUE, ...)
## S3 method for class 'optweight.svy'
summary(object, top = 5, ignore.s.weights = FALSE, weight.range = TRUE, ...)
## S3 method for class 'summary.optweight'
plot(x, ...)
object |
An |
top |
How many of the largest and smallest weights to display. Default is 5. |
ignore.s.weights |
Whether or not to ignore sampling weights when
computing the weight summary. If |
weight.range |
|
... |
Additional arguments. For |
x |
A |
For point treatments (i.e., optweight
objects),
summary()
returns a summary.optweight
object with the following
elements:
weight.range |
The range (minimum and maximum) weight for each treatment group. |
weight.top |
The units with the greatest weights
in each treatment group; how many are included is determined by |
l2 |
The square root of the L2 norm of the estimated weights from the base weights, weighted by the sampling weights (if any): |
l1 |
The L1 norm of the estimated weights from the base weights, weighted by the sampling weights (if any): |
linf |
The L |
rel.ent |
The relative entropy between the estimated weights and the base weights (entropy norm), weighted by the sampling weights (if any): |
num.zeros |
The number of units with a weight equal to 0. |
effective.sample.size |
The effective sample size for each treatment group before and after weighting. |
For multivariate treatments (i.e., optweightMV
objects), a list of
the above elements for each treatment.
For optweight.svy
objects, a list of the above elements but with no
treatment group divisions.
plot()
returns a ggplot
object with a histogram displaying the
distribution of the estimated weights. If the estimand is the ATT or ATC,
only the weights for the non-focal group(s) will be displayed (since the
weights for the focal group are all 1). A dotted line is displayed at the
mean of the weights (the mean of the base weights, or 1 if not supplied).
McCaffrey, D. F., Ridgeway, G., & Morral, A. R. (2004). Propensity Score Estimation With Boosted Regression for Evaluating Causal Effects in Observational Studies. Psychological Methods, 9(4), 403–425. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1037/1082-989X.9.4.403")}
plot.optweight()
for plotting the values of the dual variables.
library("cobalt")
data("lalonde", package = "cobalt")
#Balancing covariates between treatment groups (binary)
(ow1 <- optweight(treat ~ age + educ + married +
nodegree + re74, data = lalonde,
tols = .001,
estimand = "ATT"))
(s <- summary(ow1))
plot(s, breaks = 12)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.