Topical Information

This lab will give you practice with calling library functions (specifically some from the cmath library).

Program Information

Write a program that helps the user calculate the distance between two points in the 2D Cartesian plane. Try to make your results as readable as possible.

As an example, you might have the program interaction look something like (the parts in this color are typed by the user):

$ ./distance.out

                 Welcome to the 2D Distance Program!!!

Where is your first point?  3.4 12.2
Where is your second point?  13.4 12.2

Thank you!!  Calculating...  Done.

(3.4, 12.2) is 10 units away from (13.4, 12.2).

Thank you for using the TDP!!

Endeavor to have a wondrous day!

$

Thought Provoking Questions

1. What functions will you use from the math library? (Hint: Look at the formula for 2D distance. There should be two DIFFERENT ones.)
2. How many arguments does each function you are calling accept? What do they mean?
3. Do the arguments you pass to the function have to have certain names or values? What about types?
4. How many values are returned from each function you are calling? What do you do with these values?

This assignment is (Level 1.5).

Options

• Toward a More Natural Style of Input

  Teachers are complaining that they wish students to use proper ordered pair notation for writing out points at all times but your program not only doesn't allow them to — but forces them not to! The students are stuck between a rock and a hard place (you can decide which you are and which the teacher is; *grin*). Many of them are becoming confused.

  Add (Level 1) to make the user to enter the points in normal style. (i.e. a parenthesis, then the x value, then a comma, then the y value, then a closing parenthesis.)

  The user interaction would now look something like (the parts in this color are typed by the user):

  $ ./distance.out
  
                   Welcome to the 2D Distance Program!!!
  
  Where is your first point?  (3.4, 12.2)
  Where is your second point?  (13.4, 12.2)
  
  Thank you!!  Calculating...  Done.
  
  (3.4, 12.2) is 10 units away from (13.4, 12.2).
  
  Thank you for using the TDP!!
  
  Endeavor to have a wondrous day!
  
  $
  

  More Thought Provoking Questions

  1. How many variables are needed to make the input format more natural for the user? At minimum? At most?
  2. How can the parentheses and comma be placed right next to the numbers like that? How can cin determine where the number stops and the other stuff begins? Remember what happened when you typed a symbol or letter at a numeric prompt before? Why doesn't that cause problems here?
  3. What happens if the user doesn't type the parentheses or the comma? What happens if they type some other symbols instead? Letters instead? Digits instead? (Try input like: $4^5% and see what happens. Try 44 12x — what happens? Experiment...)

Total Level Possible

If you did all above options, this lab could be worth as much as (Level 2.5).