CODEWITHSUNDEEP
rapplylapply
unknown
unknown

Reputation: 883

Using lapply to run a function with multiple parameters

I have a function that I'd like to run with a variety of parameters (see p_space in example). I can easily do this using a for loop. However, because I am planning to use parellel processing at a later date lapply seems like the way to go. Does anyone know how I can do this? My attempts don't seem to work at all!

example code: 

as <- c(1,2)  # limit for K
bs <- c(3,4)
cs <- c(2,3)  # distribution of food sources ('random'/'clustered')

p_space <- list ()
for (a in as){
  for (b in bs){
    for (c in cs){
      p_space[[length(p_space)+1]] <- c(a,b,c)
    }
  }
}
made_up <- function(a, b, c){
  return(a * b * c)
}

My attempt to do this:

lapply(p_space, made_up(i) p_space[[i]])

My desired output is a dataframe/matrix/list with the results of the made_up function on all of the parameter sets in p_space.

How I would do this using for loops

 results <- list()

for (a in as){
  for (b in bs){
    for (c in cs){
      results[[length(results) + 1 ]] <- c(a*b*c,a,b,c)
    }}}

Upvotes: 0

Views: 921

Answers (1)

steveLangsford
steveLangsford

Reputation: 646

Maybe pass a vector to made_up and then extract a,b and c?

made_up <- function(pvec){
  return(pvec[1]*pvec[2]*pvec[3])
}

lapply(p_space,made_up)

Upvotes: 1

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