optmatch class describes the results of an
optimal full matching (using either
fullmatch or pairmatch). For
the most part, these objects can be treated as
factors. The summary function quantifies optmatch objects
on the effective sample size, the distribution of
distances between matched units, and how well the match
reduces average differences.
## S3 method for class 'optmatch':
summary(object,
propensity.model = NULL, ..., min.controls = 0.2,
max.controls = 5, quantiles = c(0, 0.5, 0.95, 1))optmatch object to summarize.glm) to use when summarizing
the match. If this object is passed and the
RItools package is loaded, an additional
chi-squared test will be performed on the average
dxBalance when also passing a propensity model.min.controls sets maximum
group sized displayed with respect to the number of
controls. Raise this value to see more groups.optmatch.summaryoptmatch objects descend from factor.
Elements of this vector correspond to members of the
treatment and control groups in reference to which the
matching problem was posed, and are named accordingly;
the names are taken from the row and column names of
distance. Each element of the vector is either
NA, indicating unavailability of any suitable
matches for that element, or the concatenation of: (i) a
character abbreviation of the name of the subclass (as
encoded using exactMatch) (ii) the string
.; and (iii) a non-negative integer. In this last
place, positive whole numbers indicate placement of the
unit into a matched set and NA indicates that all
or part of the matching problem given to fullmatch
was found to be infeasible. The functions
matched, unmatched, and
matchfailed distinguish these scenarios. Secondarily, fullmatch returns various data about
the matching process and its result, stored as attributes
of the named vector which is its primary output. In
particular, the exceedances attribute gives upper
bounds, not necessarily sharp, for the amount by which
the sum of distances between matched units in the result
of fullmatch exceeds the least possible sum of
distances between matched units in a feasible solution to
the matching problem given to fullmatch. (Such a
bound is also printed by print.optmatch and
summary.optmatch.)