Error 'Not enough input arguments'

Hi all, I am new to MATLAB software and I am having difficulty understanding this error code?

>> compacc
Error using compacc (line 8)
Not enough input arguments.

This is my data input:

function x=compacc(u)
% function to compute the slider acceleration

a = 72.36275;  % a = AB =  72.36275
b = 182.61225; % b = BC = 182.61225

w_theta  = u(1);  % w_theta  1
dw_theta = u(2);  % dw_theta 2
theta    = u(3);  % theta    3

alpha    = u(4);  % alpha    4
w_alpha  = u(5);  % w_alpha  5

A = [1.0 b*sin(alpha); 0.0 -b*cos(alpha)];

B = [-a*dw_theta*sin(theta) - a*w_theta*w_theta*cos(theta) - b*w_alpha*w_alpha*cos(alpha); ...
      a*dw_theta*cos(theta) - a*w_theta*w_theta*sin(theta) - b*w_alpha*w_alpha*sin(alpha)];

    x=inv(A)*B;

% x = [dV_d dw_alpha]

Many thanks

Answer 1

[Steven Lord]

You need to pass a value into the function, since the function is defined to accept an input argument u.

[Louis Saunders]

Thank you for the quick response, Apologies but I am still confused as to where exactly I input my value. Is this on Simulink or on the editor?

[Steven Lord]

Instead of calling it like this:

>> compacc

you would need to call it with an array that contains at least five elements, since your code accesses the fifth element of u when defining w_alpha.

w_alpha = u(5);

So try something like this:

>> compacc([1, 2, 3, 4, 5])

Note that I don't know the exact meaning of the variables to which you assign the elements of u in your code, so I just used a very simple vector to demonstrate.