Conditional Random Assignment

Robbert 0
Viewed 32

I have a question about conditional random assignment. The simplified dataset looks as below:

COMPANY         BOARDROLE               INSIDER
A               Acting Director         Yes
B               CEO                     Yes
C               Independent Director    No
D               Chairman                Unknown
E               Chairman                Unknown
F               Member                  Unknown
G               Independent Director    Outsider
H               Member                  Unknown
I               Member                  Unknown
J               Member                  Unknown

Now I want to create a fourth column, Insider Presence, that either has the value of 1 or 0. Obviously if the third column said no or outsider, there is no insider, so the Insider Presence should be 0. I know I can achieve that with the following function:

pattern <- paste(c("No", "Outsider"), collapse = "|")
df <- df %>%
  mutate(`InsiderPresence` = ifelse(str_detect(Insider, pattern), 0, 1))

But now I also want to achieve that randomly 50% of the 'Unknown' is also laballed as 1. So that you get, for example the following output:

COMPANY         BOARDROLE               INSIDER       INSIDER PRESENCE
A               Acting Director         Yes           1
B               CEO                     Yes           1
C               Independent Director    No            0 
D               Chairman                Unknown       1
E               Chairman                Unknown       0 
F               Member                  Unknown       0
G               Independent Director    Outsider      0
H               Member                  Unknown       0
I               Member                  Unknown       1
J               Member                  Unknown       1

I hope that anyone can help me

r
2 Answers

Here is an option

library(tidyverse)
df %>%
    mutate(`Insider Presence` = case_when(
        str_detect(INSIDER, "Yes") ~ 1L,
        str_detect(INSIDER, "No|Outsider") ~ 0L,
        str_detect(INSIDER, "Unknown") ~ sample(c(0L, 1L), n(), replace = TRUE),
        TRUE ~ NA_integer_))
#    COMPANY            BOARDROLE  INSIDER Insider Presence
# 1        A      Acting Director      Yes                1
# 2        B                  CEO      Yes                1
# 3        C Independent Director       No                0
# 4        D             Chairman  Unknown                1
# 5        E             Chairman  Unknown                1
# 6        F               Member  Unknown                0
# 7        G Independent Director Outsider                0
# 8        H               Member  Unknown                1
# 9        I               Member  Unknown                1
#10        J               Member  Unknown                1

We use case_when to cover all cases; the last line TRUE ~ NA_integer_ should never occur, but it is good practice to include a fall-through for debugging. We use sample to uniformly sample values with replacement from (0, 1), i.e. we draw samples from (0, 1) with a 50% probability.

Note that we draw as many samples here as there are total rows N_tot (and not just rows with INSIDER == "Unknown"). Drawing samples from N_tot with a 50% prop means that any subset will also have a 50% split (at least asymptotically for large enough sample sizes).

Sample data

df <- read.table(text = "COMPANY         BOARDROLE               INSIDER
A               'Acting Director'         Yes
B               CEO                     Yes
C               'Independent Director'    No
D               Chairman                Unknown
E               Chairman                Unknown
F               Member                  Unknown
G               'Independent Director'    Outsider
H               Member                  Unknown
I               Member                  Unknown
J               Member                  Unknown", header = T)
Maurits Evers0

This is nearly the same as MauritsEvers' already-accepted answer. The behavior in this answer is slightly different: it guarantees 50% (or rounded-up if odd rows) of Unknown will be set to 1 instead of random ratios (which could still include 0-100%).

library(dplyr)
library(stringr)
dat %>%
  group_by(grp = grepl("Unknown", INSIDER)) %>%
  mutate(Presence = case_when(
    str_detect(INSIDER, "Yes") ~ 1L,
    str_detect(INSIDER, "No|Outsider") ~ 0L,
    str_detect(INSIDER, "Unknown") ~ +(row_number() %in% sample(n(), size = ceiling(n()/2))),
    TRUE ~ NA_integer_)) %>%
  ungroup() %>%
  select(-grp)
# # A tibble: 10 x 4
#    COMPANY BOARDROLE            INSIDER  Presence
#    <chr>   <chr>                <chr>       <int>
#  1 A       Acting Director      Yes             1
#  2 B       CEO                  Yes             1
#  3 C       Independent Director No              0
#  4 D       Chairman             Unknown         0
#  5 E       Chairman             Unknown         0
#  6 F       Member               Unknown         1
#  7 G       Independent Director Outsider        0
#  8 H       Member               Unknown         1
#  9 I       Member               Unknown         0
# 10 J       Member               Unknown         1
r2evans0
Related