MATLAB: How should i Implement a function that fits a line using least squares to the 2-D data points. It should output the two parameters of a line without using a toolbox for fitting the line. And i have to do this by doing regression

ransac

I need to plot the points and the line obtained from the function. Can somebody help me writing the code?

Best Answer

the function polyfit(x,y,n) does what you need.

The MATLAB starter help example with n=1

x = linspace(0,1,5);
y = 1./(1+x);
p = polyfit(x,y,1);
x1 = linspace(0,2);
y1 = 1./(1+x1);
f1 = polyval(p,x1);
figure
plot(x,y,'o')
hold on
plot(x1,y1)
plot(x1,f1,'r--')
legend('y','y1','f1')

If you find this answer of any help solving your question, please click on the thumbs-up vote link,

thanks in advance

John

jgb2012@sky.com

Related Solutions

MATLAB: Help with linear fit

Here is one way:

x      = 0:0.05:1;                          % define data
y      = sin(x).^2;
x1     = x(10);                             % define interval
x2     = x(20);
xrange = x(find(x == x1):find(x == x2));    % pick out x and y vals in interval
yrange = y(find(x == x1):find(x == x2));
p      = polyfit(xrange, yrange, 1);        % do linear curve fit 
yfit   = polyval(p, xrange);
figure
hold on; grid; box
plot(x,y,xrange,yfit,'-r')

The first element of p is the slope of the linear curve.

MATLAB: Line plotting

for yy = 1:length(overlap_peaks2)
  x=overlap_peaks2(yy);
  y=1:200000:1000000;
  hold on;
  plot(repmat(x,1,length(y)),y, '-r')
end

By the way, you should also consider

for yy = 1:length(overlap_peaks2)
  x=overlap_peaks2(yy);
  hold on;
  plot([x x],[1 1000000], '-r')
end

Best Answer

Related Solutions

MATLAB: Help with linear fit

MATLAB: Line plotting

Related Question