CODEWITHSUNDEEP
rconditional-statementsdplyr
gabagool
gabagool

Reputation: 1161

R - dplyr - mutate_if multiple conditions

I want to mutate a column based on multiple conditions. For example, for each column where the max is 5 and the column name contains "xy", apply a function.

df <- data.frame(
  xx1 = c(0, 1, 2),
  xy1 = c(0, 5, 10),
  xx2 = c(0, 1, 2),
  xy2 = c(0, 5, 10)
)
> df

xx1 xy1 xx2 xy2
1   0   0   0   0
2   1   5   1   5
3   2  10   2  10

df2 <- df %>% mutate_if(~max(.)==10, as.character)
> str(df2)
'data.frame':   3 obs. of  4 variables:
 $ xx1: num  0 1 2
 $ xy1: chr  "0" "5" "10"
 $ xx2: num  0 1 2
 $ xy2: chr  "0" "5" "10"
#function worked
df3 <- df %>% mutate_if(str_detect(colnames(.), "xy"), as.character)
> str(df3)
'data.frame':   3 obs. of  4 variables:
 $ xx1: num  0 1 2
 $ xy1: chr  "0" "5" "10"
 $ xx2: num  0 1 2
 $ xy2: chr  "0" "5" "10"
#Worked again

Now when I try to combine them

df4 <- df %>% mutate_if((~max(.)==10) & (str_detect(colnames(.), "xy")), as.character)

Error in (~max(.) == 10) & (str_detect(colnames(.), "xy")) : operations are possible only for numeric, logical or complex types

What am I missing?

Upvotes: 3

Views: 11395

Answers (2)

Adam Lee Perelman
Adam Lee Perelman

Reputation: 890

A more concise way is to use across from dplyr

df4 <- df %>% mutate(across(c(where(function(x)max(x)==10),contains('xy')),as.character))

Upvotes: 2

gabagool
gabagool

Reputation: 1161

Had to use names instead of colnames

df4 <- df %>% mutate_if((max(.)==10 & str_detect(names(.), "xy")), as.character)

Upvotes: 5

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