Find intersection of points in a graph

Is there a way to find the intersection of two curves in the graph? If yes, can someone help me with the code

Answer 1

[Star Strider]

It would help to have the actual data. Assuming that ‘y2’ is either a constant or a line defined as a function of the same independent variable values as ‘y1’, this is straightforward —

x = linspace(0, 9);                                 % Independent Variable
y1 = 700*exp(-0.45*x);                              % Curve
y2 = 150;                                           % Line

xint = interp1(y1-y2, x, 0)                         % X-Intercept (Interpolation)

xint = 3.4236

figure
plot(x, y1,  [0 9], [1 1]*y2, xint, y2, 'sr')
legend('y_1', 'y_2', 'Intersection', 'Location','best')
text(xint, y2, sprintf('  \\leftarrow Intersection: X = %.3f',xint), 'Horiz','left', 'Vert','middle', 'Rotation',30)

See the documentation on the interp1 function for details.

If both lines are defined on different independent variable values, a separate intermediate interpolation to define them with respect to the same independent variable vector (using interp1) would be required first.

.

[Chinmayraj Doddarajappa]

Thank you

[Star Strider]

As always, my pleasure!

Answer 2

[KSSV]

You can consider using this:

https://in.mathworks.com/matlabcentral/fileexchange/22441-curve-intersections?requestedDomain=

[Chinmayraj Doddarajappa]

Thank you

Answer 3

[Hrusheekesh]

Hi chinmayraj,

You can refer to this page to find the intersection of two curves.

You can also subtract the two curves and get the absolute difference, compare with the tolerance (ex: eps) for near values.