How to fitt a power function to data

I have two 26*1 matrixes of x and y. How can I fitt a power function like (y=bx^n) to the generated graph? I just have basic fitting tool in which there is no power function. So I think I should use an appropriate code. Appreciate it.

Cheers,

Answer 1

[David Hill]

If you have the curve fitting toolbox.

f=fit(x,y,'power1');

Answer 2

[Star Strider]

This uses only basic MATLAB functions. No Toolboxes are required.

x = 1:100;                                                                          % Create Vector
y = rand(size(x));                                                                  % Create Vector

objfcn = @(b,x) b(1).*x.^b(2);                                                      % Objective Function

parms = fminsearch(@(b) norm(y - objfcn(b,x)), rand(2,1))

xv = linspace(min(x), max(x));

figure
plot(x, y, 'p')
hold on
plot(xv, objfcn(parms,xv), '-r')
hold off
title(sprintf('$y(x) = %.3f \\cdot x^{%.3f}$', parms), 'Interpreter','latex')

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