CODEWITHSUNDEEP
r
whoami
whoami

Reputation: 105

R: How to find differing values in one column based on multiple other columns

newbie R question:

So say I have a dataframe with 3 columns: id, date, and value.

How do I capture, for each id, if they have values that are different but only if the dates are different.

For example (below), id 1 would be a miss here (different value but same date), but id 2 would be a hit (different value on different dates). Id 3 would be a miss since the values don't differ.

id    date       value
1     1/1/2000     A
1     1/1/2000     B
2     1/1/2000     A
2     1/1/1999     B
3     1/1/2000     A
3     1/1/1999     A

Upvotes: 2

Views: 1212

Answers (1)

akrun
akrun

Reputation: 886948

After grouping by 'id', check whether there are more than one unique 'date' as well as on 'value' column and pass that in filter

library(dplyr)
df1 %>%
    group_by(id) %>% 
    filter(n_distinct(date) > 1, n_distinct(value) > 1)

-output

# A tibble: 2 x 3
# Groups:   id [1]
#     id date     value
#  <int> <chr>    <chr>
#1     2 1/1/2000 A    
#2     2 1/1/1999 B

Or with anyDuplicated

df1 %>%
     group_by(id) %>% 
     filter(!anyDuplicated(date), !anyDuplicated(value))
# A tibble: 2 x 3
# Groups:   id [1]
#     id date     value
#  <int> <chr>    <chr>
#1     2 1/1/2000 A    
#2     2 1/1/1999 B

data

df1 <- structure(list(id = c(1L, 1L, 2L, 2L, 3L, 3L), date = c("1/1/2000", 
"1/1/2000", "1/1/2000", "1/1/1999", "1/1/2000", "1/1/1999"), 
    value = c("A", "B", "A", "B", "A", "A")), 
    class = "data.frame", row.names = c(NA, 
-6L))

Upvotes: 3

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