I dont know how to plot more than one regressions in one plot, like the picture i did in excel. I tried basic fitting tool but could not success, and i have look at multiple regression but could not understand becaus of no example. Thank for any help

Answer 1

[Star Strider]

Something like this should work:

x = 1:10;
y1 = rand(1, 10);
y2 = rand(1, 10);

DM = [x', ones(length(x),1)];                       % Design Matrix
B1 = DM \ y1';                                      % Estimate Parameters Of ‘y1’ Fit
B2 = DM \ y2';                                      % Estimate Parameters Of ‘y2’ Fit

y1_fit = DM*B1;                                     % Calculate Fit For ‘y1’
y2_fit = DM*B2;                                     % Calculate Fit For ‘y2’

figure(1)
plot(x, y1, '.b',  x, y2, '.r')                     % Plot Data
hold on
plot(x, y1_fit, '--b',  x, y2_fit, '--r')           % Plot Fitted Regression Lines
hold off
grid

[Manh Nguyen]

thank a lot, it was so headeach

[Star Strider]

My pleasure.

If my Answer solved your problem, please Accept it.

Answer 2

[Image Analyst]

If you want a polyfit() example, see attached. Like Star showed, you just do the fit first for the first set of data, and plot that fit, then call hold on, and do it again for the second set of data.

[Manh Nguyen]

Thank yo Image Analyst