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Use starts_with inside map instead of explicitly naming

Drop data frame columns by nameChange values in row based on a column value and replacing specified column rangeCombining rows for selected columnsIterating through a multi-dimensional dataset in RCreate column of a tibble (or data frame) that contains a list from a long-format tibbleDummy code categorical / ordinal variables in the tidyverse rconditional lag calculations using RUsing pmap to apply different regular expressions to different variables in a tibble?Using pmap with a to apply different regular expressions to different variables in a tibble?Mapping the same function to multiple tibbles in a list

.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;

0

I want to apply a function inside a tibble but I don't want to explicitly Name the columns. E.G.

library(tidyverse)
library(tidyselect)
test = tibble(var1 = c("la", "le", "lu"), var2 = c("ma", "me", "mu"), var3 = c("fi", "fa", "fu"), dummy=1)
with_funct = test %>% mutate(blub = pmap_chr(list(var1, var2, var3), paste, sep='+'))

I get the expected result:

# A tibble: 3 x 5
 var1 var2 var3 dummy blub 
 <chr> <chr> <chr> <dbl> <chr> 
 1 la ma fi 1 la+ma+fi
 2 le me fa 1 le+me+fa
 3 lu mu fu 1 lu+mu+fu

But instead of writing list(var1, var2, var3) I'd prefer to use starts_with("var") but this does not work out.

So if I use

with_funct = test %>% mutate(blub = pmap_chr(starts_with("var"), paste, sep='+'))

I get an

"Error: No tidyselect variables were registered"

I'd appreciate any help.

r tidyselect

share|improve this question

asked Mar 27 at 15:49

MichaelAMichaelA

76311 gold badge88 silver badges2727 bronze badges

add a comment | 

0

I want to apply a function inside a tibble but I don't want to explicitly Name the columns. E.G.

library(tidyverse)
library(tidyselect)
test = tibble(var1 = c("la", "le", "lu"), var2 = c("ma", "me", "mu"), var3 = c("fi", "fa", "fu"), dummy=1)
with_funct = test %>% mutate(blub = pmap_chr(list(var1, var2, var3), paste, sep='+'))

I get the expected result:

# A tibble: 3 x 5
 var1 var2 var3 dummy blub 
 <chr> <chr> <chr> <dbl> <chr> 
 1 la ma fi 1 la+ma+fi
 2 le me fa 1 le+me+fa
 3 lu mu fu 1 lu+mu+fu

But instead of writing list(var1, var2, var3) I'd prefer to use starts_with("var") but this does not work out.

So if I use

with_funct = test %>% mutate(blub = pmap_chr(starts_with("var"), paste, sep='+'))

I get an

"Error: No tidyselect variables were registered"

I'd appreciate any help.

r tidyselect

share|improve this question

asked Mar 27 at 15:49

MichaelAMichaelA

76311 gold badge88 silver badges2727 bronze badges

add a comment | 

I want to apply a function inside a tibble but I don't want to explicitly Name the columns. E.G.

library(tidyverse)
library(tidyselect)
test = tibble(var1 = c("la", "le", "lu"), var2 = c("ma", "me", "mu"), var3 = c("fi", "fa", "fu"), dummy=1)
with_funct = test %>% mutate(blub = pmap_chr(list(var1, var2, var3), paste, sep='+'))

I get the expected result:

# A tibble: 3 x 5
 var1 var2 var3 dummy blub 
 <chr> <chr> <chr> <dbl> <chr> 
 1 la ma fi 1 la+ma+fi
 2 le me fa 1 le+me+fa
 3 lu mu fu 1 lu+mu+fu

But instead of writing list(var1, var2, var3) I'd prefer to use starts_with("var") but this does not work out.

So if I use

with_funct = test %>% mutate(blub = pmap_chr(starts_with("var"), paste, sep='+'))

I get an

"Error: No tidyselect variables were registered"

I'd appreciate any help.

r tidyselect

share|improve this question

asked Mar 27 at 15:49

MichaelAMichaelA

76311 gold badge88 silver badges2727 bronze badges

library(tidyverse)
library(tidyselect)
test = tibble(var1 = c("la", "le", "lu"), var2 = c("ma", "me", "mu"), var3 = c("fi", "fa", "fu"), dummy=1)
with_funct = test %>% mutate(blub = pmap_chr(list(var1, var2, var3), paste, sep='+'))

# A tibble: 3 x 5
 var1 var2 var3 dummy blub 
 <chr> <chr> <chr> <dbl> <chr> 
 1 la ma fi 1 la+ma+fi
 2 le me fa 1 le+me+fa
 3 lu mu fu 1 lu+mu+fu

with_funct = test %>% mutate(blub = pmap_chr(starts_with("var"), paste, sep='+'))

share|improve this question

asked Mar 27 at 15:49

MichaelAMichaelA

76311 gold badge88 silver badges2727 bronze badges

share|improve this question

asked Mar 27 at 15:49

MichaelAMichaelA

76311 gold badge88 silver badges2727 bronze badges

asked Mar 27 at 15:49

MichaelAMichaelA

76311 gold badge88 silver badges2727 bronze badges

asked Mar 27 at 15:49

MichaelAMichaelA

76311 gold badge88 silver badges2727 bronze badges

2 Answers
2

active

oldest

votes

1

You could use select() inside pmap_chr() to work on just the columns that starts with "var". I use the dot to refer to the dataset being used in mutate().

One reasons this works is because pmap() works rowwise across a tibble. The way I'm using this the columns are used in the function (paste() in your case) in the order they appear in the dataset.

test %>% 
 mutate(blub = pmap_chr(select(., starts_with("var")), paste, sep='+'))

# A tibble: 3 x 5
 var1 var2 var3 dummy blub 
 <chr> <chr> <chr> <dbl> <chr> 
1 la ma fi 1 la+ma+fi
2 le me fa 1 le+me+fa
3 lu mu fu 1 lu+mu+fu

share|improve this answer

answered Mar 27 at 15:57

aosmithaosmith

23.4k44 gold badges4848 silver badges7676 bronze badges

add a comment | 

2

Try this:

with_funct2 = test %>% mutate(blub = pmap_chr(test %>% select(starts_with("var")), paste, sep='+'))

Hope it helps

share|improve this answer

answered Mar 27 at 15:57

FALL GoraFALL Gora

36877 bronze badges

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  This works fine here, but if there is any grouping or modification to the data before getting to this mutate, then this will be wrong: it'll be using the original (unmodified test) data. Better to use (as aosmith shows) the . placeholder instead, as it will include data as it exists at this point in time in the pipe.
  
  – r2evans
  Mar 27 at 15:59
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  agreed! more flexible
  
  – FALL Gora
  Mar 27 at 16:01
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  your Version works, but I cannot just change "test" to "." that throws an error.
  
  – MichaelA
  Mar 27 at 16:12
  

  
  
  
  

add a comment | 

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1

You could use select() inside pmap_chr() to work on just the columns that starts with "var". I use the dot to refer to the dataset being used in mutate().

One reasons this works is because pmap() works rowwise across a tibble. The way I'm using this the columns are used in the function (paste() in your case) in the order they appear in the dataset.

test %>% 
 mutate(blub = pmap_chr(select(., starts_with("var")), paste, sep='+'))

# A tibble: 3 x 5
 var1 var2 var3 dummy blub 
 <chr> <chr> <chr> <dbl> <chr> 
1 la ma fi 1 la+ma+fi
2 le me fa 1 le+me+fa
3 lu mu fu 1 lu+mu+fu

share|improve this answer

answered Mar 27 at 15:57

aosmithaosmith

23.4k44 gold badges4848 silver badges7676 bronze badges

add a comment | 

1

You could use select() inside pmap_chr() to work on just the columns that starts with "var". I use the dot to refer to the dataset being used in mutate().

One reasons this works is because pmap() works rowwise across a tibble. The way I'm using this the columns are used in the function (paste() in your case) in the order they appear in the dataset.

test %>% 
 mutate(blub = pmap_chr(select(., starts_with("var")), paste, sep='+'))

# A tibble: 3 x 5
 var1 var2 var3 dummy blub 
 <chr> <chr> <chr> <dbl> <chr> 
1 la ma fi 1 la+ma+fi
2 le me fa 1 le+me+fa
3 lu mu fu 1 lu+mu+fu

share|improve this answer

answered Mar 27 at 15:57

aosmithaosmith

23.4k44 gold badges4848 silver badges7676 bronze badges

add a comment | 

You could use select() inside pmap_chr() to work on just the columns that starts with "var". I use the dot to refer to the dataset being used in mutate().

One reasons this works is because pmap() works rowwise across a tibble. The way I'm using this the columns are used in the function (paste() in your case) in the order they appear in the dataset.

test %>% 
 mutate(blub = pmap_chr(select(., starts_with("var")), paste, sep='+'))

# A tibble: 3 x 5
 var1 var2 var3 dummy blub 
 <chr> <chr> <chr> <dbl> <chr> 
1 la ma fi 1 la+ma+fi
2 le me fa 1 le+me+fa
3 lu mu fu 1 lu+mu+fu

share|improve this answer

answered Mar 27 at 15:57

aosmithaosmith

23.4k44 gold badges4848 silver badges7676 bronze badges

test %>% 
 mutate(blub = pmap_chr(select(., starts_with("var")), paste, sep='+'))

# A tibble: 3 x 5
 var1 var2 var3 dummy blub 
 <chr> <chr> <chr> <dbl> <chr> 
1 la ma fi 1 la+ma+fi
2 le me fa 1 le+me+fa
3 lu mu fu 1 lu+mu+fu

share|improve this answer

answered Mar 27 at 15:57

aosmithaosmith

23.4k44 gold badges4848 silver badges7676 bronze badges

answered Mar 27 at 15:57

aosmithaosmith

23.4k44 gold badges4848 silver badges7676 bronze badges

answered Mar 27 at 15:57

aosmithaosmith

23.4k44 gold badges4848 silver badges7676 bronze badges

2

Try this:

with_funct2 = test %>% mutate(blub = pmap_chr(test %>% select(starts_with("var")), paste, sep='+'))

Hope it helps

share|improve this answer

answered Mar 27 at 15:57

FALL GoraFALL Gora

36877 bronze badges

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  This works fine here, but if there is any grouping or modification to the data before getting to this mutate, then this will be wrong: it'll be using the original (unmodified test) data. Better to use (as aosmith shows) the . placeholder instead, as it will include data as it exists at this point in time in the pipe.
  
  – r2evans
  Mar 27 at 15:59
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  agreed! more flexible
  
  – FALL Gora
  Mar 27 at 16:01
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  your Version works, but I cannot just change "test" to "." that throws an error.
  
  – MichaelA
  Mar 27 at 16:12
  

  
  
  
  

add a comment | 

2

Try this:

with_funct2 = test %>% mutate(blub = pmap_chr(test %>% select(starts_with("var")), paste, sep='+'))

Hope it helps

share|improve this answer

answered Mar 27 at 15:57

FALL GoraFALL Gora

36877 bronze badges

• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  This works fine here, but if there is any grouping or modification to the data before getting to this mutate, then this will be wrong: it'll be using the original (unmodified test) data. Better to use (as aosmith shows) the . placeholder instead, as it will include data as it exists at this point in time in the pipe.
  
  – r2evans
  Mar 27 at 15:59
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  agreed! more flexible
  
  – FALL Gora
  Mar 27 at 16:01
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  your Version works, but I cannot just change "test" to "." that throws an error.
  
  – MichaelA
  Mar 27 at 16:12
  

  
  
  
  

add a comment | 

Try this:

with_funct2 = test %>% mutate(blub = pmap_chr(test %>% select(starts_with("var")), paste, sep='+'))

Hope it helps

share|improve this answer

answered Mar 27 at 15:57

FALL GoraFALL Gora

36877 bronze badges

with_funct2 = test %>% mutate(blub = pmap_chr(test %>% select(starts_with("var")), paste, sep='+'))

share|improve this answer

answered Mar 27 at 15:57

FALL GoraFALL Gora

36877 bronze badges

answered Mar 27 at 15:57

FALL GoraFALL Gora

36877 bronze badges

answered Mar 27 at 15:57

FALL GoraFALL Gora

36877 bronze badges