diagnose {MatchIt} | R Documentation |
diagnose
is a sub-function of matchit
which calculates summary
statistics for the matching, including the weight for each unit.
diagnose <- diagnose(formula, match.matrix, pscore, in.sample, data, exact=FALSE, mahvars=NULL, subclass=0, psclass=NULL, nearest=TRUE, q.cut=NULL, counter=TRUE)
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 in the same data frame. The + symbol means
"inclusion" not "addition." You may also include interaction terms in the form if
I(X1*X2) or squared terms in the form of I(X1^2) . |
match.matrix |
(required). n1 by ratio data frame where the rows correspond to treated
units and the columns store the names of the control units matched to each treated unit. NA
indicates that treated unit was not matched. Generally created in nearest . |
pscore |
(required). Vector of estimated propensity scores. Generally calculated in
distance . |
in.sample |
(required). Vector of length n showing whether each unit was eligible for
matching due to common support restrictions with discard . Generally calculated in
distance . |
data |
(required). Data frame containing the variables called in the formula .
The dataframe should not include variables with the names psclass , psweights , or
pscore , as these are expressly reserved in the output dataframe for MatchIt. |
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 propensity
score. |
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 . |
subclass |
Either a scaler specifying the number of subclasses (default=0) or a
vector of probabilities to create quantiles based on sub.by . |
psclass |
Subclass index in an ordinal scale from 1 to the number of subclasses.
Unmatched units have subclass=0. Generally computed in subclassify . |
nearest |
Whether to perform nearest-neighbor matching (default=TRUE). |
q.cut |
Subclass cut points. Generally calculated in subclassify . |
counter |
Whether to display counter indicating the progress of the matching (default=TRUE). |
This is a sub-function of matchit
which calculates summary statistics for the
matching procedure in matchit
, calculating t-statistics for covariates as well as
weights for each unit. This function is called directly by matchit
and does not
generally need to be called directly by users; these details are included for advanced users.
psweights |
Vector of length n giving the weight assigned to each unit in the matching process. Each weight is proportional to the number of times that unit was matched. |
Daniel Ho <deho@fas.harvard.edu>; Kosuke Imai <kimai@princeton.edu>; Gary King <king@harvard.edu>; Elizabeth Stuart<stuart@stat.harvard.edu>
Please use help.matchit
to access the matchit reference
manual. The complete document is available online at
http://gking.harvard.edu/matchit.