CODEWITHSUNDEEP
rdataframeapply
Valentin
Valentin

Reputation: 23

Apply method in R missing argument (missing argument error)

I am trying to use the apply method in R. But I keep getting the error: Error in FUN(newX[, i], ...) : missing argument in "b".

The code which produces the error:

my_data <- data.frame(x1 = 1:5, x2 = 2:6, x3 = 3)

myFunction <- function(a, b, c){
  return(a + b + c)
}

results = apply(my_data, 1, myFunction) #this line is producing the error massage

If I change "myFunction" to "sum" for example. Then there is no error. How can I get rid of this error?

Upvotes: 1

Views: 383

Answers (3)

SmokeyShakers
SmokeyShakers

Reputation: 3412

Also note your data.frame is a list of 3 vectors. You can add vectors just like a scalar.

with(my_data, x1 + x2 + x3)

Upvotes: 1

LMc
LMc

Reputation: 18632

You can use mapply:

with(my_data, mapply(myFunction, x1, x2, x3))

Upvotes: 1

akrun
akrun

Reputation: 887118

Either the function should be changed to

myFunction <- function(x) sum(x)
apply(my_data, 1, myFunction)
#[1]  6  8 10 12 14

Also, the sum operation by row is more efficient with rowSums

rowSums(my_data)

or specify the arguments separately by using a lambda/anonymous function in the OP's original function

apply(my_data, 1, function(x) myFunction(x[1], x[2], x[3]))

Upvotes: 2

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