visualFields (version 0.6.2)

vfselectvisit: select visits per subject from a vf-object

Description

select a determined amount of visits a vf-object. This is done if the interest is to select the last n visits, or the first n visits, or visits within a range, etc

Usage

vfselectvisit( vf, sel = "last", numTests = 1,
               beginDate = NA, endDate = NA )

Arguments

vf

a vf-object

sel

Type of selection, do we want visits from last, from first first, within a date range, or specific visit numbers. Default is last

numTests

number of tests to select from last, first, or a date range. If sel is an array of indices or set to a date range, numTests is overruled. Default is 1

beginDate

when sel = "date" is date from (inclusive). If it is NA, then the data is set to 1900-01-01. Default is NA

endDate

when sel = "date" is date to (inclusive). If it is NA, then the data is set to today. Default is NA

Value

returns the subselected visits per subject. For those subject for which at least numTests visits could not be selected are completely removed

Examples

# NOT RUN {
  vfselectvisit( vf91016left )
# }