psmatch2 depvar [indepvars] [if exp] [in range] [, outcome(varlist) pscore(varname) neighbor(integer) radius caliper(real) mahalanobis(varlist) ai(integer) population altvariance
                     kernel llr kerneltype(type) bwidth(real) spline nknots(integer) common trim(real) noreplacement descending odds index logit ties quietly w(matrix) ate]

        where indepvars and mahalanobis(varlist) may contain factor variables; see fvvarlist.

请Stata高手讲解此命令的详细含义。感激不尽感激不尽！