Size Estimates By Name Apply (Loops)

If the data on dinosaur lengths with species names is not in your working directory then download it. Import it using read_csv().

The following function estimates a dinosaur’s mass based on its length and name of its taxonomic group:

get_mass_from_length_by_name <- function(length, name){
  if (name == "Stegosauria"){
    mass = 10.95 * length ^ 2.64
  }
  else if (name == "Theropoda"){
    mass = 0.73 * length ^ 3.63
  }
  else if (name == "Sauropoda"){
    mass = 214.44 * length ^ 1.46
  }
  else {
    mass = NA
  }
  return(mass)
}

1. Copy this function into your code and then use this function and mapply() to calculate the estimated mass for each dinosaur. You’ll need to pass the data to mapply() as single vectors or columns, not the whole data frame.

2. Using dplyr, add a new masses column to the data frame (using rowwise(), mutate() and your function) and print the result to the console.

3. Using ggplot, make a histogram of dinosaur masses with one subplot for each species (using facet_wrap()).