CODEWITHSUNDEEP
rfunctionplot
momo12321
momo12321

Reputation: 141

R: Providing parameters to a function?

I have a function called plot() . I want my function to be in a way such that if the user just inputs plot() it will plot all the rows in the data that is read inside the function ( inside plot() data will be read )

I also want the user to be able to choose which rows he wants to plot from the data. So if the user inputs plot(1) , function will plot the first row. If user inputs plot(1,3) it'll plot the first and the third rows.

I tried doing that but I'm not sure how.

This is what I tried to do:

plot <- function(x){
if(x==0)
{ //reads the whole file and plots all the rows
}
else
{
//reads the specified rows and plots them
}
}

This works only if the user wants to plot one row as in the case of plot(1) , but doesn't work if the user wants more than one row (i.e plot(1,2,3) ).

Help?

Upvotes: 1

Views: 33

Answers (1)

LAP
LAP

Reputation: 6685

test <- function(...){
  rows <- c(...)
  if(!is.null(rows) & !is.integer(rows)){stop("Input is not an integer"!)}
  if(max(rows) > nrow(data)){stop("Out of bounds!")}
  if(is.null(rows)){
    plot(data)
  }else{
    plot(data[rows,])
  }
}

The ... lets you put in anything you want, so this will need some error prevention.

The function just creates a vector of the input, checks for length to see if input was given, then plots either the whole dataset (no input given) or the lines determined by the vector rows.

Edit: Changed first error prevention from numeric to integer.

In the long run, you will probably need more error prevention with this kind of input, but for now it should work.

Upvotes: 2

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