Create a parameter object for the function matchOnPs

  caliper = 0.2,
  caliperScale = "standardized logit",
  maxRatio = 1,
  stratificationColumns = c()



The caliper for matching. A caliper is the distance which isacceptable for any match. Observations which are outside of thecaliper 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 toeach person in the treatment arm. A maxRatio of 0 means no maximum:all comparators will be assigned to a target person.


Names or numbers of one or more columns in the data data.frameon which subjects should be stratified prior to matching. No personswill be matched with persons outside of the strata identified by thevalues in these columns.


Create an object defining the parameter values.