39 lines
817 B
Matlab
39 lines
817 B
Matlab
close all
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clear all
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load thymusglandweights.dat
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literature_mean = 34.3;
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x = thymusglandweights;
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n = length(x);
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y = x - mean(x) + literature_mean;
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m = 2000;
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me = zeros(m,1);
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for i = 1:m
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me(i) = mean(y(randi(n,n,1)));
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end
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hist(me, 50);
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hold on
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mu = mean(x);
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plot([mu,mu],[0,200],'--r','LineWidth',3);
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xlabel('thymus gland weights [g]');
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ylabel('frequency');
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title('bootstrapped null distribution');
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hold off
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% 5% significance boundaries
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low = quantile(me,0.025);
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high = quantile(me,0.975);
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disp(['the 5% boundaries are: ', num2str(low), ' ', num2str(high)]);
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hold on
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plot([low,low],[0,200],'--g','LineWidth',3);
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plot([high,high],[0,200],'--g','LineWidth',3);
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hold off
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pval = mean(abs(me-literature_mean) > abs(mu - literature_mean))
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legend('Null distribution','measured mean','5% significance boundaries')
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