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Kepler State Transition Matrix (MEX)

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from Kepler State Transition Matrix (MEX) by Rody Oldenhuis
Compute Kepler state transition matrix for an arbitrary number of time steps. M and C++ version.

test_STM.m 
% 36526 times
clc
dt = 0:10:1000*365.25;
Mtime = zeros(numel(dt), 1);
MEXtime = Mtime;

state = [150e6, 0, -2e3, 1.2, 29.4, 0.01];
muC   = 1.32e11;


for ii = 1:numel(dt)
    
    % get 100 random days
    TIMES = dt(round( 36525*rand(100,1)+1 ));
    
    % show progress
    fprintf(1, '%3d%% complete...', round(100*ii/numel(dt)))
    
    % test M-version
    start = tic;
        A = progress_orbitM(TIMES, state, muC);
    Mtime(ii) = toc(start);
    
    % test MEX-version
    start = tic;
        B = progress_orbit(TIMES(:), state, muC);
    MEXtime(ii) = toc(start);
    
    % delete progress
    fprintf(1, '\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b')
end

% plot speedup
figure(1), hold on
plot(1:numel(dt), Mtime./MEXtime, 'b')

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