Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

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


Math Forum » Discussions » Software » comp.soft-sys.matlab

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

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
dpb

Posts: 8,112
Registered: 6/7/07
Re: curve interpolation by parabolic blending
Posted: Jun 22, 2013 7:08 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic 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...

--




Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.