Create a parameter object for the function matchOnPsAndCovariates

  caliper = 0.2,
  caliperScale = "standardized logit",
  maxRatio = 1,



The caliper for matching. A caliper is the distance which is acceptablefor any match. Observations which are outside of the caliper are dropped.A caliper of 0 means no caliper is used.


The scale on which the caliper is defined. Three scales are supported:caliperScale = 'propensity score', caliperScale ='standardized', or caliperScale = 'standardized logit'.On the standardized scale, the caliper is interpreted in standarddeviations of the propensity score distribution. 'standardized logit'is similar, except that the propensity score is transformed to the logitscale because the PS is more likely to be normally distributed on that scale(Austin, 2011).


The maximum number of persons int the comparator arm to be matched to eachperson in the treatment arm. A maxRatio of 0 means no maximum: allcomparators will be assigned to a target person.


One or more covariate IDs in the cohortMethodData object on whichsubjects should be also matched.


Create an object defining the parameter values.