Reference

Matching on raw covariates
multiMatch()	Matching Estimators for Multiple Treatments from Yang et al. (2016).
multilevelMatchX()	Matching on X with multilevel treatments
Matching on generalized propensity scores
multiMatch()	Matching Estimators for Multiple Treatments from Yang et al. (2016).
multilevelGPSMatch()	Matching on GPS with multilevel treatments
Stratification on generalized propensity scores
multilevelGPSStratification()	Stratification on GPS with multilevel treatments