Rank: 328 based on 277 downloads (last 30 days) and 5 files submitted
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Nikolai Chernov

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Company/University
University of Alabama at Birmingham
Lat/Long
33.5, -86.81

Personal Profile:
Professional Interests:
statistics, image processing

 

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Files Posted by Nikolai View all
Updated   File Tags Downloads
(last 30 days)
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16 Jan 2009 Screenshot Ellipse Fit (Direct method) Fits an ellipse to a set of points on a plane; returns the coefficients of the ellipse's equation Author: Nikolai Chernov image processing, statistics, optimization, least squares, potw, pick of the week 90 13
  • 4.16667
4.2 | 6 ratings
14 Jan 2009 Screenshot Ellipse Fit (Taubin method) Fits an ellipse to a set of points on a plane; returns coefficients of the ellipse's equation. Author: Nikolai Chernov image processing, statistics, probabilty, optimization, least squares, potw 29 1
  • 4.0
4.0 | 2 ratings
13 Jan 2009 Screenshot Circle Fit (Taubin method) Fits a circle to a set of data points on a plane; returns the circle center (a,b) and radius R. Author: Nikolai Chernov image processing, statistics, optimization, fitting curves, least squares, probability 55 4
  • 4.66667
4.7 | 6 ratings
10 Jan 2009 Screenshot Circle Fit (Pratt method) Fits a circle to a set of data points on a plane; returns the circle center (a,b) and radius R. Author: Nikolai Chernov image processing, statistics, mathematics, regression, fitting curves, probability 71 1
  • 5.0
5.0 | 2 ratings
10 Jan 2009 Screenshot Circle Fit (Kasa method) Fits a circle to a given set of planar points Author: Nikolai Chernov statistics, optimization, image processing, regression, fitting curves, probabilty 32 1
  • 5.0
5.0 | 1 rating
Comments and Ratings by Nikolai View all
Updated File Comments Rating
16 Jan 2009 Ellipse Fit (Direct method) Fits an ellipse to a set of points on a plane; returns the coefficients of the ellipse's equation Author: Nikolai Chernov

from Author: XY is the Nx2 input array of coordinates of N points,
x(i)=XY(i,1), y(i)=XY(i,2). To use the program, type
A = EllipseDirectFit(XY)

07 Jan 2009 Circle fit Fit a circle to a set of measured x,y points. Author: Izhak Bucher

This circle fit has been first published by P.Delogne and I.Kasa in the 1970s and is known as "Kasa method" in statistics. It works well when points cover a large part of the circle but is heavily biased when points are restricted to a small arc. Better fits were proposed by Pratt and Taubin.

Comments and Ratings on Nikolai's Files View all
Updated File Comment by Comments Rating
05 Sep 2014 Ellipse Fit (Direct method) Fits an ellipse to a set of points on a plane; returns the coefficients of the ellipse's equation Author: Nikolai Chernov Po-Yu

29 Jul 2014 Ellipse Fit (Direct method) Fits an ellipse to a set of points on a plane; returns the coefficients of the ellipse's equation Author: Nikolai Chernov Tim

I get a filled structure, but somehow it doesn't draw the plot. Am I missing something?

02 Jul 2014 Ellipse Fit (Taubin method) Fits an ellipse to a set of points on a plane; returns coefficients of the ellipse's equation. Author: Nikolai Chernov Christian

The information from Ed Shen (in the comments about Ellipse Fit (Direct method)) is crucial for this function too: "The code works, however you must divde A(2), A(4) and A(5) by 2 to be able to use it with the Mathworld equations."
Without these divisions the rusulting elippse does not really fit to the points.

02 Jul 2014 Ellipse Fit (Direct method) Fits an ellipse to a set of points on a plane; returns the coefficients of the ellipse's equation Author: Nikolai Chernov Christian

The information from Ed Shen is crucial: "The code works, however you must divde A(2), A(4) and A(5) by 2 to be able to use it with the Mathworld equations."
Without these divisions the rusulting elippse does not really fit to the points.

05 Nov 2013 Ellipse Fit (Direct method) Fits an ellipse to a set of points on a plane; returns the coefficients of the ellipse's equation Author: Nikolai Chernov K

Hello,

I am trying to use this file to fit an ellipse to an elliptical hysteresis loop from data points in a 2X200 array. I get the error "Attempted to access A(4); index out of bounds because numel(A)=0." I am not sure what the problem is- can you help?

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