I'm not sure exactly what you are trying to achieve but I think I can help you out anyway.
You are incrementing vp in each iteration but I'm guessing that you want all the variables you set after the first time you set vp to be affected by this change as well.
An easy way for you to achieve this with your current code:
- First, comment out line #35 : r has not been set yet, and you have the same code inside your for-loop.
- Move line #37 to line #6 to recalculate all your variables with the new value of vp
This will give you three results for values of vp: 48, 50 and 52