Matlab:Refined population model: Difference between revisions
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m (remove P from simulation script, reason) |
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% If you want to modify the constants, please bear these restrictions in mind: | % If you want to modify the constants, please bear these restrictions in mind: | ||
% -C should be an integer | % -C should be an integer | ||
% -D, B, F, K | % -D, B, F, K should be values in [0,1] | ||
% -B should be greater than K (or else, the number of witches will be negative) | % -B should be greater than K (or else, the number of witches will be negative) | ||
% -W(1) should be strictly positive. If W(1)=0, no witch appear ever, and MSes grow linearily | % -W(1) should be strictly positive. If W(1)=0, no witch appear ever, and MSes grow linearily | ||
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C = 100; % Number of girls contracted by QBe | C = 100; % Number of girls contracted by QBe | ||
D = 0. | D = 0.200; % Proportion of girls (who are fighting) that die | ||
B = 0. | B = 0.100; % Proportion of girls (who are fighting) to become witches | ||
F = 0.015; % Proportion of familiars becoming witches | F = 0.015; % Proportion of familiars becoming witches | ||
K = 0. | K = 0.096; % Proportion of witches getting killed by MSes | ||
steps = 500; % Number of iterations for the simulation | steps = 500; % Number of iterations for the simulation | ||
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for t=1:steps | for t=1:steps | ||
prop = | prop = min(M(t), W(t)); | ||
deltaM = C- prop*(D+B); | deltaM = C- prop*(D+B); |
Revision as of 06:53, 22 March 2011
% % REFINED MAGICAL GIRL-WITCH POPULATION MODEL % This file has been produced for FreeMat 4.0 % The syntax of the plot commands may differ from Matlab. % % If you want to modify the constants, please bear these restrictions in mind: % -C should be an integer % -D, B, F, K should be values in [0,1] % -B should be greater than K (or else, the number of witches will be negative) % -W(1) should be strictly positive. If W(1)=0, no witch appear ever, and MSes grow linearily % C = 100; % Number of girls contracted by QBe D = 0.200; % Proportion of girls (who are fighting) that die B = 0.100; % Proportion of girls (who are fighting) to become witches F = 0.015; % Proportion of familiars becoming witches K = 0.096; % Proportion of witches getting killed by MSes steps = 500; % Number of iterations for the simulation M(1) = 0; % Number of magical girls at first W(1) = 1; % Number of witches at first hold on for t=1:steps prop = min(M(t), W(t)); deltaM = C- prop*(D+B); deltaW = F*W(t) + prop*(B-K); M(t+1)=M(t)+deltaM; W(t+1)=W(t)+deltaW; end title('Evolution of the Magical Girls population over time') xlabel('time') ylabel('number of magical girls/witches') plot(M, 'g.-') plot(W, 'r.-') legend('Magical Girls', 'Witches', 'location', 'northeast') legend('boxoff') hold off