MATLAB最小二乘法拟合直线的程序.doc

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1、最小二乘法拟合直线程序：functionlinear_fit%最小二乘法拟合直线clear;clc;prompt={'Nameofdatafile'};title='Linear_fit';lineNo=2;def={'Linearfit.dat'};outval=inputdlg(prompt,title,lineNo,def);ifisempty(outval)==1,return,endfilename=outval{1};data=load(filename);x=data(:,1);y=data(:,2);[a,b]=

2、linearfit(x,y);yy=a+b*x;func=['y=',num2str(a),'+',num2str(b),'*x'];plot(x,y,'bx','markersize',10);holdonplot(x,yy,'r-','linewidth',1.5)xlabel('T(^oC)');ylabel('R(Omega)');text(x(2),yy(length(yy)-1),func)function[a,b]=linearfit(x,y)xy=x.*y;x2=x.^2;x_mean=mean(x);y_me

3、an=mean(y);xy_mean=mean(xy);x2_mean=mean(x2);b=(xy_mean-x_mean*y_mean)/(x2_mean-x_mean^2);a=y_mean-b*x_mean;return运行情况：按“run”运行时，弹出窗口注：在Linearfit.dat文件中数据为：04.38104.56204.70304.86405.08505.24605.40705.58805.74905.961006.061106.261206.44点击图框中的“OK”，在“commandwindow”中输出结

4、果为：1306.581406.741506.941607.121707.281807.421907.602007.78