Rank: 326 based on 196 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
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(last 30 days) 		Comments Rating
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 36 8
  • 3.0
3.0 | 2 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, least squares, optimization, probabilty, potw 38 0
  • 4.0
4.0 | 1 rating
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 fitting curves, optimization, statistics, image processing, least squares, probability 62 2
  • 4.5
4.5 | 4 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, fitting curves, regression, probability 43 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 fitting curves, statistics, image processing, optimization, probabilty, regression 17 1
  • 5.0
5.0 | 1 rating
Comments and Ratings by Nikolai View all
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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
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Updated File Comment by Comments Rating
01 Dec 2011 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 David
09 Aug 2011 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 jinrong
14 Sep 2010 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 Sarkar, Shriniket

I tried using an XY array of
575 562
589 201
495 614
799 443
729 540
Using this set it provides exponential values for a,b and c return parameters and we cant use these parameters for a plot.

Is there something i am missing in this ? Can someone help?
02 Jul 2010 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 Lopes, Manuel

Works nicely, can be easily extended to 3D data.

%project 3D data to a plane
[U,S,V]=svd(XYr);
XYp = U'*XYr;

Pare = CircleFitByTaubin(XYp(1:2,:)')

%estimated center
UU = U * [Pare(1:2)';0];
%estimated radius
RR = Pare(end);
29 Apr 2010 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 GAURAV

I have three points say (a1,b1),(a2,b2),(a3,b3)..
How do I paas this as input?? Please let me know..

Appreciate your help.

Thank You,
Gaurav.
Top Tags Applied by Nikolai
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image processing, statistics, optimization, fitting curves, least squares
Files Tagged by Nikolai View all
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Updated   File Tags Downloads
(last 30 days) 		Comments Rating
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 36 8
  • 3.0
3.0 | 2 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, least squares, optimization, probabilty, potw 38 0
  • 4.0
4.0 | 1 rating
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 fitting curves, optimization, statistics, image processing, least squares, probability 62 2
  • 4.5
4.5 | 4 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, fitting curves, regression, probability 43 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 fitting curves, statistics, image processing, optimization, probabilty, regression 17 1
  • 5.0
5.0 | 1 rating

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