Linear Regression, line of best fit

If I have data for vectors x = [ ] and y= [ ], how do I find and plot the linear regression/line of best fit? Once I have plotted the line of best fit, how do I record the slope of that line of best fit to some variable "a"?

Answer 1

[KSSV]

Read about polyfit https://in.mathworks.com/help/matlab/ref/polyfit.html

To fit a line use n=1.

Answer 2

[Jaimin]

Hi @YM,

I understand that the goal is to determine the linear regression/line of best fit for a dataset and to find the corresponding slope.

To achieve this, you can use the "polyfit" function. I have included a sample code snippet below for clearer understanding:

% Sample data vectors x and y 
x = [1, 2, 3, 4, 5]; % Replace with your data 
y = [2, 4, 6, 8, 10]; % Replace with your data 

% Find the coefficients of the linear regression (slope and intercept) 
coefficients = polyfit(x, y, 1); 

% Extract the slope (first coefficient) 
a = coefficients(1); 
 
% Generate the values of the line of best fit 
y_fit = polyval(coefficients, x); 

% Plot the original data 
figure; 
plot(x, y, 'o', 'DisplayName', 'Data Points'); % Original data points 
hold on; 
 
% Plot the line of best fit 
plot(x, y_fit, '-', 'DisplayName', 'Line of Best Fit'); % Line of best fit 

% Add labels and legend 
xlabel('x'); 
ylabel('y'); 
title('Linear Regression / Line of Best Fit'); 
legend show; 

% Display the slope in the command window 
disp(['The slope of the line of best fit is: ', num2str(a)]); 

The slope of the line of best fit is: 2

For more information on “polyfit” function, you can refer to the following documentation.

https://www.mathworks.com/help/matlab/ref/polyfit.html

I hope this helps.