Count non-NA values by group

user_1700890 0
Viewed 58612

Here is my example

mydf<-data.frame('col_1' = c('A','A','B','B'), 'col_2' = c(100,NA, 90,30))

I would like to group by col_1 and count non-NA elements in col_2

I would like to do it with dplyr. Here is what I tried:

mydf %>% group_by(col_1) %>% summarise_each(funs(!is.na(col_2)))
mydf %>% group_by(col_1) %>% mutate(non_na_count = length(col_2, na.rm=TRUE))
mydf %>% group_by(col_1) %>% mutate(non_na_count = count(col_2, na.rm=TRUE))

Nothing worked. Any suggestions?

dplyr na count r group-by
3 Answers
library(knitr)
library(dplyr)

mydf <- data.frame("col_1" = c("A", "A", "B", "B"), 
                   "col_2" = c(100, NA, 90, 30))

mydf %>%
  group_by(col_1) %>%
  select_if(function(x) any(is.na(x))) %>%
  summarise_all(funs(sum(is.na(.)))) -> NA_mydf

kable(NA_mydf)
user_73648730
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