Linear Fit and Axes Labeling

I've created a scatter plot, but I also want the linear fit of this plot. Is there a command for this. Also, how can I label both axes and add a title to the plot?

Answer 1

[Christiaan]

Dear Suyapa,

There are may possible ways to plot a linear fit in a scattered plot (with least squares for example). This is also called linear regression. Therefore in MATLAB you can use one of the linear regression tools.

Documentation can be found here: http://www.mathworks.com/help/stats/linear-regression-model-workflow.html

You can have a look at the examples, and then I am sure you find one that suits your problem.

Kind regards, Christiaan

Answer 2

[Star Strider]

There are several ways to do what you want. If you have the Statistics Toolbox, consider the lsline function.

Otherwise, consider polyfit (and polyval) with a first-degree polynomial:

b  = polyfit(x, y, 1);
yf = polyval(b, x);

then plot it as:

figure(1)
scatter(x, y)
hold on
plot(x, yf)
hold off
title('Scatterplot of (x,y) data')
xlabel('x data')
ylabel('y data')

This works best if your x-data are ordered.

See the documentation for the plot function for other options.