max_cond {admiral}

Maximum Value on a Subset

Description

The function derives the maximum value of a vector/column on a subset of entries/observations.

Usage

max_cond(var, cond)

Arguments

var

A vector

cond

A condition

See Also

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

Examples

library(tibble)
library(dplyr, warn.conflicts = FALSE)
library(admiral)
data <- tribble(
  ~USUBJID, ~AVISITN, ~AVALC,
  "1",      1,        "PR",
  "1",      2,        "CR",
  "1",      3,        "NE",
  "1",      4,        "CR",
  "1",      5,        "NE",
  "2",      1,        "CR",
  "2",      2,        "PR",
  "2",      3,        "CR",
)

# In oncology setting, when needing to check the first time a patient had
# a Complete Response (CR) to compare to see if any Partial Response (PR)
# occurred after this add variable indicating if PR occurred after CR
group_by(data, USUBJID) %>% mutate(
  first_cr_vis = min_cond(var = AVISITN, cond = AVALC == "CR"),
  last_pr_vis = max_cond(var = AVISITN, cond = AVALC == "PR"),
  pr_after_cr = last_pr_vis > first_cr_vis
)