Code for Given three points (x1, y1), (x2, y2) and (x3, y3), write a program to check if all the three points fall on one straight line.

Given three points (x1, y1), (x2, y2) and (x3, y3), write a program to check if all the three points fall on one straight line.

Answer 1

[Venkat Siddarth Reddy]

Hi Ravi,

To achieve this you can use the concept of slopes i.e. if the slope between (x1, y1) and (x2,y2), and between (x2,y2) and (x3,y3) are equal then points lie on a straight line.

Following is the implementation of above logic in MATLAB

function isCollinear = checkCollinearity(x1, y1, x2, y2, x3, y3)
    % Calculate the "slope" conditions using cross multiplication in case
    % to avoid division.
    % (y2 - y1) * (x3 - x2) == (y3 - y2) * (x2 - x1)
    % If the above condition is true, then the points are collinear.
    
    isCollinear = (y2 - y1) * (x3 - x2) == (y3 - y2) * (x2 - x1);
end

Call the above functions with the co-ordinates as arguments

% Define the points
x1 = 1; y1 = 1;
x2 = 2; y2 = 2;
x3 = 3; y3 = 3;

% Check if the points are collinear
if checkCollinearity(x1, y1, x2, y2, x3, y3)
    disp('The points fall on one straight line.');
else
    disp('The points do not fall on one straight line.');
end

The points fall on one straight line.

Hope it helps!