as.weightit: Create a 'weightit' object manually

In WeightIt: Weighting for Covariate Balance in Observational Studies

Create a weightit object manually

Description

This function allows users to get the benefits of a weightit object when using weights not estimated with weightit() or weightitMSM(). These benefits include diagnostics, plots, and direct compatibility with cobalt for assessing balance.

Usage

as.weightit(x, ...)

## S3 method for class 'weightit.fit'
as.weightit(x, covs = NULL, ...)

## Default S3 method:
as.weightit(
  x,
  treat,
  covs = NULL,
  estimand = NULL,
  s.weights = NULL,
  ps = NULL,
  ...
)

as.weightitMSM(x, ...)

## Default S3 method:
as.weightitMSM(
  x,
  treat.list,
  covs.list = NULL,
  estimand = NULL,
  s.weights = NULL,
  ps.list = NULL,
  ...
)

Arguments

x	required; a numeric vector of weights, one for each unit, or a weightit.fit object from weightit.fit().
...	additional arguments. These must be named. They will be included in the output object.
covs	an optional data.frame of covariates. For using WeightIt functions, this is not necessary, but for use with cobalt it is. Note that when using with a weightit.fit object, this should not be the matrix supplied to the covs argument of weightit.fit() unless there are no factor/character variables in it. Ideally this is the original, unprocessed covariate data frame with factor variables included.
treat	a vector of treatment statuses, one for each unit. Required when x is a vector of weights.
estimand	an optional character of length 1 giving the estimand. The text is not checked.
s.weights	an optional numeric vector of sampling weights, one for each unit.
ps	an optional numeric vector of propensity scores, one for each unit.
treat.list	a list of treatment statuses at each time point.
covs.list	an optional list of data.frames of covariates of covariates at each time point. For using WeightIt functions, this is not necessary, but for use with cobalt it is.
ps.list	an optional list of numeric vectors of propensity scores at each time point.

Value

An object of class weightit (for as.weightit()) or weightitMSM (for as.weightitMSM()).

Examples

treat <- rbinom(500, 1, .3)
weights <- rchisq(500, df = 2)

W <- as.weightit(weights, treat = treat, estimand = "ATE")
summary(W)

# See ?weightit.fit for using as.weightit() with a
# weightit.fit object.

WeightIt documentation built on April 4, 2025, 2:05 a.m.