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function ek = Kepler(mk,e) |
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% ek = Kepler(mk,e) |
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% Kepler - Solves Kepler's equation for ek through iteration. |
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% |
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% Inputs: mk: mean anomaly (rad) |
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% e: eccentricity |
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% Outputs: ek: eccentric anomaly |
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% |
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% NOTE: mk and e may be a vectors of the same dimensions, or one may be a scalar |
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% the output is a vector of the same dimensions as the input vector |
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%Author: Frank van Diggelen |
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%Open Source code for processing Android GNSS Measurements |
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%Check inputs size |
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if min(size(mk))>1 |
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error('mk must be a vector or a scalar, not a matrix') |
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end |
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if min(size(e))>1 |
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error('e must be a vector or a scalar, not a matrix') |
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end |
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if length(mk)>1 && length(e)>1 && any(size(mk)~=size(e)) |
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%both are vectors, they must have the same dimensions |
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error('If mk and e are both vectors they must have the same dimensions') |
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end |
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err = 1; |
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ek=mk; |
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iterCount = 0; |
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maxIterCount = 20; |
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while any(abs(err) > 1e-8) && iterCount < maxIterCount |
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err = ek - mk - (e.*sin(ek)); |
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ek = ek - err; |
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iterCount = iterCount + 1; |
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if iterCount == maxIterCount |
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fprintf('Failed convergence on Kepler''s equation.\n') |
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end |
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end |
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end %end of function Kepler |
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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% Copyright 2016 Google Inc. |
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% |
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% Licensed under the Apache License, Version 2.0 (the "License"); |
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% you may not use this file except in compliance with the License. |
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% You may obtain a copy of the License at |
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% |
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% http://www.apache.org/licenses/LICENSE-2.0 |
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% |
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% Unless required by applicable law or agreed to in writing, software |
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% distributed under the License is distributed on an "AS IS" BASIS, |
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% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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% See the License for the specific language governing permissions and |
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% limitations under the License. |
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