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 map2_dbl() to calculate the estimated mass for each dinosaur. You’ll need to pass the data to map2_dbl() 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()).