Practicing with Custom Functions Answer Key

Exercises

1. Custom Functions - Let’s create a function temp_conv(), which converts the temperature in Fahrenheit (input) to the temperature in Kelvin (output). Let’s perform a two-step calculation: first convert from Fahrenheit to Celsius, and then convert from Celsius to Kelvin.

   • The formula for celsius to farenheight: temp_c = (temp_f - 32) * 5 / 9
   • The formula for celsius to kelvin: temp_k = temp_c + 273.15
   • Test your function. If your input is 70, the result of temp_conv(70) should be 294.2611.

# Create temp_conv_function
temp_conv <- function(temp_f) {
  temp_c = (temp_f - 32) * 5 / 9
  temp_k = temp_c + 273.15
  return (temp_k)
}

2. Nesting Functions - Now we want to round the temperature in Kelvin (output of temp_conv()) to a single decimal place.

   • Use the round() function with the newly-created temp_conv() function to achieve this in one line of code.
   • If your input is 70, the output should now be 294.3.

# Round output of temp_conv to 1 digit
round(temp_conv(70), digits = 1)

[1] 294.3