How to fit this curve?

x = [39.224 49.03 58.836 68.642 78.448 88.254 98.06 107.866 117.672 127.478 137.284];

y = [2.4218 3.9931 6.0817 8.7791 12.1994 16.4867 21.8260 28.4584 36.7052 47.0032 59.9637];

[Walter Roberson]

Use plot() and grid on and label the axes.

[Gabriel Costa]

Thanks!

[Tatti Singh]

Thanks for the help. I was looking the same.

Answer 1

[Star Strider]

The best model is the mathematical expression of the process that created those data.

A power law fit appears to provide a reasonable approximation:

x  = [39.224 49.03 58.836 68.642 78.448 88.254 98.06 107.866 117.672 127.478 137.284];
y = [2.4218 3.9931 6.0817 8.7791 12.1994 16.4867 21.8260 28.4584 36.7052 47.0032 59.9637];

fcn = @(b,x) b(1).*x.^b(2);

B = fminsearch(@(b) norm(y - fcn(b,x)), rand(2,1));     % Power Law

figure
plot(x, y, '.')
hold on
plot(x, fcn(B,x), '-r')
hold off
grid
xlabel('X')
ylabel('Y')

producing:

.

[Gabriel Costa]

Thanks!

[Star Strider]

As always, my pleasure!

Answer 2

[Tatti Singh]

Thanks for it.