Making Choices

Modify the Code 2

The following function is intended to check if two geographic points are close to one another. If they are it should return TRUE. If they aren’t, it should return FALSE. Two points are considered near to each other if the absolute value of the difference in their latitudes is less than one and the absolute value of the difference in their longitudes is less than one.

1. Fill in the _________ in the function to make it work.

   near <- function(lat1, long1, lat2, long2){
       # Check if two geographic points are near each other 
       if ((abs(lat1 - lat2) < 1) & (_________){
           near <- TRUE
       } else {
           near <- _________
       }
       return(near)
   }
   

2. Improve the documentation for the function so that it is clear what near means and what output the user should expect.
3. Check if Point 1 (latitude = 29.65, longitude = -82.33) is near Point 2 (latitude = 41.74, longitude = -111.83).
4. Check if Point 1 (latitude = 29.65, longitude = -82.33) is near Point 2 (latitude = 30.5, longitude = -82.8).
5. Create a new version of the function that improves it by allowing the user to pass in a parameter that sets what “near” means. To avoid changing the existing behavior of the function (since some of your lab mates are using it already) give the parameter a default value of 1.
6. Improve the documentation for the new function so that it reflects this new behavior
7. Check if Point 1 (latitude = 48.86, longitude = 2.35) is near Point 2 (latitude = 41.89, longitude = 2.5), when near is set to 7.

[click here for output]