filter_extreme: Filter the First or Last Observation for Each By Group

In Roche-GSK/admiral: ADaM in R Asset Library

Filter the First or Last Observation for Each By Group

Description

Filters the first or last observation for each by group.

Usage

filter_extreme(dataset, by_vars = NULL, order, mode, check_type = "warning")

Arguments

dataset	Input dataset The variables specified by the by_vars and order arguments are expected to be in the dataset. Default value none
by_vars	Grouping variables Default value NULL
order	Sort order Within each by group the observations are ordered by the specified order. Permitted values list of expressions created by exprs(), e.g., exprs(ADT, desc(AVAL)) Default value none
mode	Selection mode (first or last) If "first" is specified, the first observation of each by group is included in the output dataset. If "last" is specified, the last observation of each by group is included in the output dataset. Permitted values "first", "last" Default value none
check_type	Check uniqueness? If "warning" or "error" is specified, the specified message is issued if the observations of the input dataset are not unique with respect to the by variables and the order. Permitted values "none", "message", "warning", "error" Default value "warning"

Details

For each group (with respect to the variables specified for the by_vars parameter) the first or last observation (with respect to the order specified for the order parameter and the mode specified for the mode parameter) is included in the output dataset.

Value

A dataset containing the first or last observation of each by group

See Also

Utilities for Filtering Observations: count_vals(), filter_exist(), filter_joined(), filter_not_exist(), filter_relative(), max_cond(), min_cond()

Examples

library(dplyr, warn.conflicts = FALSE)

ex <- tribble(
  ~STUDYID,  ~DOMAIN,  ~USUBJID, ~EXSEQ, ~EXDOSE,    ~EXTRT,
  "PILOT01",    "EX", "01-1442",      1,      54,    "XANO",
  "PILOT01",    "EX", "01-1442",      2,      54,    "XANO",
  "PILOT01",    "EX", "01-1442",      3,      54,    "XANO",
  "PILOT01",    "EX", "01-1444",      1,      54,    "XANO",
  "PILOT01",    "EX", "01-1444",      2,      81,    "XANO",
  "PILOT01",    "EX", "05-1382",      1,      54,    "XANO",
  "PILOT01",    "EX", "08-1213",      1,      54,    "XANO",
  "PILOT01",    "EX", "10-1053",      1,      54,    "XANO",
  "PILOT01",    "EX", "10-1053",      2,      54,    "XANO",
  "PILOT01",    "EX", "10-1183",      1,       0, "PLACEBO",
  "PILOT01",    "EX", "10-1183",      2,       0, "PLACEBO",
  "PILOT01",    "EX", "10-1183",      3,       0, "PLACEBO",
  "PILOT01",    "EX", "11-1036",      1,       0, "PLACEBO",
  "PILOT01",    "EX", "11-1036",      2,       0, "PLACEBO",
  "PILOT01",    "EX", "11-1036",      3,       0, "PLACEBO",
  "PILOT01",    "EX", "14-1425",      1,      54,    "XANO",
  "PILOT01",    "EX", "15-1319",      1,      54,    "XANO",
  "PILOT01",    "EX", "15-1319",      2,      81,    "XANO",
  "PILOT01",    "EX", "16-1151",      1,      54,    "XANO",
  "PILOT01",    "EX", "16-1151",      2,      54,    "XANO"
)


# Select first dose for each patient
ex %>%
  filter_extreme(
    by_vars = exprs(USUBJID),
    order = exprs(EXSEQ),
    mode = "first"
  ) %>%
  select(USUBJID, EXSEQ)

# Select highest dose for each patient on the active drug
ex %>%
  filter(EXTRT != "PLACEBO") %>%
  filter_extreme(
    by_vars = exprs(USUBJID),
    order = exprs(EXDOSE),
    mode = "last",
    check_type = "none"
  ) %>%
  select(USUBJID, EXTRT, EXDOSE)

Roche-GSK/admiral documentation built on April 14, 2025, 12:36 p.m.