R8218/fitLine2.m
2a92558b8ca5master

fitLine2.m
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			function [dirVect,meanX,residuals,rmse,R2] = fitLine2(X)

			% Fits a line to a group of points in X

			[coeff,score,roots] = princomp(X);
			dirVect = coeff(:,1);
			[Xn,Xm] = size(X);
			meanX = mean(X,1);
			Xfit1 = repmat(meanX,Xn,1) + score(:,1)*coeff(:,1)';
			residuals = X-Xfit1;
			error = diag(pdist2(residuals,zeros(Xn,Xm)));
			sse = sum(error.^2);
			rmse = norm(error)/sqrt(Xn);

			for i=1:Xn;
			tot(i) = norm(meanX-X(i,:));
			end

			sst = sum(tot.^2);

			R2 = 1-(sse/sst); %http://en.wikipedia.org/wiki/Coefficient_of_determination
			end