Expressions and Variables

More Variables

Calculate a total biomass in grams for 3 large Pacific oysters (Crassostrea gigas) and then convert it to kilograms. The total biomass is three times the average size of a single individual. An average individual weighs 250 grams.

  1. Add a new section to your R script starting with a comment.
  2. Create a variable grams and assign it the mass of a single Crassostrea gigas.
  3. Create a variable number and assign it the number of individuals.
  4. Create a variable biomass and assign it a value by multiplying the two variables together.
  5. Convert the value of biomass into kilograms (there are 1000 grams in a kilogram so divide by 1000) and assign this value to a new variable.
  6. Print the final answer to the screen.

Are the variable names grams, number, and biomass the best choice? If we came back to the code for this assignment in two weeks (without the assignment itself in hand) would we be able to remember what these variables were referring to and therefore what was going on in the code? The variable name biomass is also kind of long. If we had to type it many times it would be faster just to type b. We could also use really descriptive alternatives like individual_mass_in_grams. Or we would compromise and abbreviate this or leave out some of the words to make it shorter (e.g., indiv_mass_g).

Think about good variable names and then rename the variables in your program to what you find most useful. Make sure your code still runs properly after you’ve changed the names.

[click here for output]