Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Ellipse trouble
#1
Photo 
I want to make a program that creates dots in the shape of an ellipse.

So not knowing about the math involved I assumed it would be fairly simple.   Then I googled and youtubed and that didn't help much.   I did end up with a mild headache though.

There's a fancy formula that stands out from everything I've been learning, but I really don't know how to use it properly.   So I thought I'd ask here, in case anyone knows.

The formula is:


x2/a2 + y2/b2 = 1     ( x-squared over a-squared + y-squared over b-squared = 1)


It's been too long since I've worked with algebra so I'm just unsure of how to solve for x.    The "=1" part is not helping at all  Big Grin


I've learned the basic principles of the ellipse itself, and so here is an example I'm working with:


The ellipse is 200 wide (2a) by 100 tall  (2b)

a = 100
b = 50
located at position 0,0

I know the distance between the focal points is 86.603 in this case

If I could understand how to find a simple x,y point, I'm sure I'd be on my way to writing a program immediately.

The top center point in this case is x0, y50.   So I'm wondering what the x value is if y=48.   Or if y=46.   Or all the way to y=2.    

Cheers,
James
Reply


Messages In This Thread
Ellipse trouble - by james2464 - 08-23-2022, 03:29 PM
RE: Ellipse trouble - by dcromley - 08-23-2022, 04:07 PM
RE: Ellipse trouble - by james2464 - 08-23-2022, 06:37 PM
RE: Ellipse trouble - by bplus - 08-23-2022, 04:54 PM
RE: Ellipse trouble - by james2464 - 08-23-2022, 06:43 PM
RE: Ellipse trouble - by James D Jarvis - 08-23-2022, 05:37 PM
RE: Ellipse trouble - by james2464 - 08-23-2022, 06:48 PM
RE: Ellipse trouble - by bplus - 08-23-2022, 08:51 PM
RE: Ellipse trouble - by james2464 - 08-23-2022, 11:33 PM
RE: Ellipse trouble - by Pete - 08-24-2022, 12:47 AM
RE: Ellipse trouble - by james2464 - 08-24-2022, 01:59 PM
RE: Ellipse trouble - by Pete - 08-25-2022, 02:23 AM
RE: Ellipse trouble - by james2464 - 08-25-2022, 11:38 AM
RE: Ellipse trouble - by Pete - 08-25-2022, 08:58 PM
RE: Ellipse trouble - by james2464 - 08-25-2022, 10:52 PM



Users browsing this thread: 12 Guest(s)