Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: curve interpolation by parabolic blending
Replies: 2   Last Post: Jun 23, 2013 3:38 AM

 Search Thread: Advanced Search

 Messages: [ Previous | Next ]
 dpb Posts: 9,850 Registered: 6/7/07
Re: curve interpolation by parabolic blending
Posted: Jun 22, 2013 7:08 PM
 Plain Text Reply

On 6/22/2013 7:06 AM, enprush@gmail.com wrote:
> I'm given a set of 25 points(x,y values). I need to curve fit these
> points using a parabolic blending. I'm not sure how to go about it. I
> read that we need to take 3 points at a time to ensure a unique parabola
> is obtained.
> I need to:
> take first 3 points(1,2,3) and fit a parabola to it.
> take the next 3 points (2,3,4) and do the same.
> This goes on till i reach my final point. The overlapping portions
> of any two parabolas is linearly blend using a cubic curve.
>
> So, this looks more like a polyfit of third order except between
> point 1 and 2. Am i right in continuing on with a ployfit of order 3?

Well, you can certainly find the coefficients of the quadratic at each
set of three points w/ polyfit and use polyval to evaluate it over the
range.

I don't know the details of how the blending is supposed to work so
can't suggest much on that point w/o having some reference to work from.
A quick google turned up several references but none that weren't more
reading that had time to delve into...

--

Date Subject Author
6/22/13 enprush@gmail.com
6/22/13 dpb
6/23/13 Bruno Luong

© The Math Forum at NCTM 1994-2018. All Rights Reserved.