Usage
matchdef <- matchdef(formula, in.sample, pscore, nearest=TRUE, replace=FALSE,
m.order=2, ratio=1, caliper=0, calclosest=FALSE, mahvars=NULL, exact=FALSE,
data=NULL, counter=TRUE)
Arguments
formula
(required). Takes the form of T ~ X1 + X2, where T is a binary
treatment indicator and X1 and X2 are the pre-treatment covariates, and T,
X1, and X2 are contained
data
Data frame containing the variables in formula.
in.sample
Vector of length n showing whether each unit was eligible for matching due to
common support restrictions with discard. Computed in distance.
pscore
Vector of propensity scores, calculated in distance.
nearest
Whether to perform nearest-neighbor matching (default=TRUE).
replace
Whether to match with replacement (default=FALSE).
m.order
Order in which to match treated units with control units. 1=optimal (requires ``optmatch" package),
2 (default)=from high to low, 3=from low to high, 4=random order.
ratio
The number of control units to be matched to each treated unit (default=1).
caliper
Standard deviations of the propensity score within which to draw control
units (default=0).
calclosest
If caliper!=0, whether to take the nearest available match if
no matches are available within caliper (default=FALSE).
mahvars
Variables on which to perform Mahalanobis matching within each caliper
(default=NULL). Should be entered as a vector of names of variables in data.
exact
"FALSE" (default)=no exact matching. "TRUE"=exact matching on all
variables in formula. A vector of variable names (that are in data) to indicate
separate variables on which to exact match, in combination with matching on the p
counter
Whether to display counter indicating the progress of the matching
(default=TRUE).