Name

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      ELL_3PT_CIRCLE

Purpose

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      Fit a circle to 3 points on an ellipsoid.

Category

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Calling Sequence

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      ell_3pt_circle, p1, p2, p3, pc

Inputs

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      p1, p2, p3 = 3 given points. in

Keyword Parameters

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Keywords

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        RADIUS=rd Returned radius of circle (m).
        /DEBUG Debug. Assumes a map is ready to plot on.
        ERROR=err 0=ok, else did not fit the circle.
        NUM_ITERATIONS=cnt Number of iterations to get within
          tolerance (small, like <4).

Outputs

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      pc = Returned center of circle. out
        Points are structures: {lon:lon, lat:lat}.

Common Blocks

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Notes

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Modification History

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      R. Sterner, 2007 Aug 05
      R. Sterner, 2007 Sep 17 --- Corrected call to ell_point_sep.
      R. Sterner, 2008 Mar 19 --- Used tol/2 in ell_dist_match.
      R. Sterner, 2008 Nov 25 --- Returned with error if no fit.
  Copyright (C) 2007, Johns Hopkins University/Applied Physics Laboratory
  This software may be used, copied, or redistributed as long as it is not
  sold and this copyright notice is reproduced on each copy made. This
  routine is provided as is without any express or implied warranties
  whatsoever. Other limitations apply as described in the file disclaimer.txt.