Use to specify stratification variables for VPC.

stratify(o, ...)

# S3 method for tidyvpcobj
stratify(o, formula, data = o$data, ...)

Arguments

o

A tidyvpcobj.

...

Other arguments to include.

formula

Formula for stratification.

data

Observed data supplied in observed() function.

Value

Returns updated tidyvpcobj with stratification formula, stratification column(s), and strat.split datasets, which is obs split by unique levels of stratification variable(s). Resulting datasets are of class object data.frame

and data.table.

Examples

# \donttest{
require(magrittr)

vpc <- observed(obs_data, x=TIME, y=DV) %>%
    simulated(sim_data, y=DV) %>%
    stratify(~ GENDER) %>%
    binning(NTIME) %>%
    vpcstats()

# Example with 2-way stratification by GENDER and STUDY.

vpc <- vpc %>%
    stratify(~ GENDER + STUDY) %>%
    binning(bin = "centers", centers = c(1,3,5,7,10)) %>%
    vpcstats()
# }