% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/plot.summary.matchit.R
\name{plot.summary.matchit}
\alias{plot.summary.matchit}
\title{Generate a Love Plot of Standardized Mean Differences}
\usage{
\method{plot}{summary.matchit}(
  x,
  abs = TRUE,
  var.order = "data",
  threshold = c(0.1, 0.05),
  position = "bottomright",
  ...
)
}
\arguments{
\item{x}{a \code{summary.matchit} object; the output of a call to
\code{\link[=summary.matchit]{summary.matchit()}}. The \code{standardize} argument must be set to
\code{TRUE} (which is the default) in the call to \code{summary}.}

\item{abs}{\code{logical}; whether the standardized mean differences should
be displayed in absolute value (\code{TRUE}, default) or not \code{FALSE}.}

\item{var.order}{how the variables should be ordered. Allowable options
include \code{"data"}, ordering the variables as they appear in the
\code{summary} output; \code{"unmatched"}, ordered the variables based on
their standardized mean differences before matching; \code{"matched"},
ordered the variables based on their standardized mean differences after
matching; and \code{"alphabetical"}, ordering the variables alphabetically.
Default is \code{"data"}. Abbreviations allowed.}

\item{threshold}{numeric values at which to place vertical lines indicating
a balance threshold. These can make it easier to see for which variables
balance has been achieved given a threshold. Multiple values can be supplied
to add multiple lines. When \code{abs = FALSE}, the lines will be displayed
on both sides of zero. The lines are drawn with \code{abline} with the
linetype (\code{lty}) argument corresponding to the order of the entered
variables (see options at \code{\link[=par]{par()}}). The default is \code{c(.1, .05)} for a
solid line (\code{lty = 1}) at .1 and a dashed line (\code{lty = 2}) at .05,
indicating acceptable and good balance, respectively. Enter a value as
\code{NA} to skip that value of \code{lty} (e.g., \code{c(NA, .05)} to have
only a dashed vertical line at .05).}

\item{position}{the position of the legend. Should be one of the allowed
keyword options supplied to \code{x} in \code{\link[=legend]{legend()}} (e.g., \code{"right"},
\code{"bottomright"}, etc.). Default is \code{"bottomright"}. Set to
\code{NULL} for no legend to be included. Note that the legend will cover up
points if you are not careful; setting \code{var.order} appropriately can
help in avoiding this.}

\item{\dots}{ignored.}
}
\value{
A plot is displayed, and \code{x} is invisibly returned.
}
\description{
Generates a Love plot, which is a dot plot with variable names on the y-axis
and standardized mean differences on the x-axis. Each point represents the
standardized mean difference of the corresponding covariate in the matched
or unmatched sample. Love plots are a simple way to display covariate
balance before and after matching. The plots are generated using
\code{\link[=dotchart]{dotchart()}} and \code{\link[=points]{points()}}.
}
\details{
For matching methods other than subclassification,
\code{plot.summary.matchit} uses \code{x$sum.all[,"Std. Mean Diff."]} and
\code{x$sum.matched[,"Std. Mean Diff."]} as the x-axis values. For
subclassification, in addition to points for the unadjusted and aggregate
subclass balance, numerals representing balance in individual subclasses are
plotted if \code{subclass = TRUE} in the call to \code{summary}. Aggregate
subclass standardized mean differences are taken from
\code{x$sum.across[,"Std. Mean Diff."]} and the subclass-specific mean
differences are taken from \code{x$sum.subclass}.
}
\examples{

data("lalonde")
m.out <- matchit(treat ~ age + educ + married +
                   race + re74, data = lalonde,
                 method = "nearest")
plot(summary(m.out, interactions = TRUE),
     var.order = "unmatched")

s.out <- matchit(treat ~ age + educ + married +
                   race + nodegree + re74 + re75,
                 data = lalonde, method = "subclass")
plot(summary(s.out, subclass = TRUE),
     var.order = "unmatched", abs = FALSE)

}
\seealso{
\code{\link[=summary.matchit]{summary.matchit()}}, \code{\link[=dotchart]{dotchart()}}

\pkgfun{cobalt}{love.plot} is a more flexible and sophisticated function to make
Love plots and is also natively compatible with \code{matchit} objects.
}
\author{
Noah Greifer
}
