count rows with conditons on summarise

Question

I am trying to count records on summarize given conditions as the code bellow but it is not working. I am trying to count total rows, not a distinct count.

What am I doing wrong?

library(dplyr)

data %>%
    group_by(UNIT) %>%
    summarize(TOTAL = n(),
              SLA = n(DATETIME[TYPE=='A' || TYPE=='B']))

Appreciate any help

What are `DATETIME` and `TYPE`? Another dataframe? Columns in `data`? Could you provide an extract of your data? In addition to the advice below to use `sum`, I suspect you want to use `|` (vectorized) rather than `||` (not vectorized; see https://stackoverflow.com/q/6558921/17303805), but it’s hard to say without understanding the structure of your data. — zephryl, Feb 18 '22 at 15:12

Johan Rosa · Accepted Answer · 2022-02-18T14:40:29.077

1

use sum instead of n

library(dplyr)

set.seed(123)

data <- data.frame(
  UNIT = sample(1:3, size = 100, replace = TRUE),
  TYPE = sample(c('A', 'B', 'C'), size = 100, replace = TRUE)
)

head(data)
#>   UNIT TYPE
#> 1    3    C
#> 2    3    B
#> 3    3    B
#> 4    2    C
#> 5    3    A
#> 6    2    A

data %>%
  group_by(UNIT) %>%
  summarise(TOTAL = n(), SLA = sum(TYPE == 'A' | TYPE == 'B'))
#> # A tibble: 3 × 3
#>    UNIT TOTAL   SLA
#>   <int> <int> <int>
#> 1     1    33    22
#> 2     2    32    19
#> 3     3    35    27

^{Created on 2022-02-18 by the reprex package (v2.0.1)}

edited Feb 18 '22 at 14:40

answered Feb 18 '22 at 13:29

Johan Rosa

2,797
10
18

1

This will work, I would also recommend `DATETIME[TYPE %in% c('A', 'B')]` which is easier to extend to many more conditions. – qdread Feb 18 '22 at 13:30
hello sum does not for POSIXt object I guess – Jonathan Livingston Seagull Feb 18 '22 at 13:30
What is the desired result? Just number of rows where `TYPE` is A or B? If so, then you do not need to involve the `DATETIME` column at all – qdread Feb 18 '22 at 13:31
2

Just removed the DATETIME variable. It is always good to include in your questions a minimal reprex of your data and desired output. That way we can help you better and faster. – Johan Rosa Feb 18 '22 at 13:35
hi, it gives me unexpected token ' [ ' – Jonathan Livingston Seagull Feb 18 '22 at 13:41
Try now, sorry. – Johan Rosa Feb 18 '22 at 13:43
hi unfortunately on SLA column I get integer 1 – Jonathan Livingston Seagull Feb 18 '22 at 14:15
Now my answer is a full reproducible example of what you should do. The problem was the `||` It have to be only one `|`. – Johan Rosa Feb 18 '22 at 14:42
Yes, this was the problem. It is working now. Many thanks. – Jonathan Livingston Seagull Feb 18 '22 at 19:49
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/242163/discussion-between-johan-rosa-and-jonathan-livingston-seagull). – Johan Rosa Feb 18 '22 at 23:07

count rows with conditons on summarise

1 Answers1