CODEWITHSUNDEEP
rfunctiontext
WeakLearner
WeakLearner

Reputation: 938

R function with text input

I have a function in R that takes as input a matrix and outputs a data frame with:

name   X    Y      Z
  Amy   25     40   78
  Brad    67    78   90
   ..

I would like to add a parameter to the function that is text, like this:

  f(x,NameChoice) { #...matrix calcs #
                return( subset( dataframe, Name = NameChoice ) )
}

so that f(x,Amy) would have output:

Amy   25     40   78

Upvotes: 0

Views: 2084

Answers (3)

Praveen Kesani
Praveen Kesani

Reputation: 178

here is code with out suspect method.

name val1 val2 val3 val4
abc    1    5    9   13
def    2    6   10   14
ghi    3    7   11   15
klm    4    8   12   16

fun<-function(x,NameChoice){
  return(x[which(x$name==NameChoice),])
}

fun(df,'ghi')

result:
ghi    3    7   11   15

Upvotes: 1

Praveen Kesani
Praveen Kesani

Reputation: 178

i think you will expecting this:

df
name val1 val2 val3 val4
abc    1    5    9   13
def    2    6   10   14
ghi    3    7   11   15
klm    4    8   12   16


f<- function(x,NameChoice) { 
  return( subset( x, name == NameChoice ) )
}

f(df,'abc')

result:
name val1 val2 val3 val4
abc    1    5    9   13

Upvotes: 1

IRTFM
IRTFM

Reputation: 263342

Try this (noting that the help page for subset specifically advises NOT to use it in a function);

func.in <- function(){cat("Enter colname and press enter:")
   readLines(n = 1)}  # No need for quotes since readline will "see" as character.

f <- function(inp)  # enter the dataframe of interest
        return(  inp[ , func.in()])

}

#Example of use:
> f(inp)
Enter colname and press enter:
X
[1] 25 67

Need to use the '[' function for extraction rather than subset.

Upvotes: 1

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