find non zero elements in array

im trying to implement find non zero elements without using "find' toolbox in simulink. im using matlab function block as shown on the screenshot

function y = non_zero(u)
x=find(u);
y=x

Answer 1

[Soniya Jain]

As mentioned in the error, that y is non-tunable, so have you tried to select the 'Variable Size' checkbox by specifying the upper bounds in the Size box?

Also, find function will return the index of the non zero elements in a vector, so if you want values at the index, you can code in the following way:

function y = non_zero(u)
x = find(u);  % will return index of non-zero elements
y = y(x);
end

[Le Dyk Zuy]

i need the index of the non zero elements in a vector, not the actual value

[Soniya Jain]

So have you tried to select the 'Variable Size' checkbox by specifying the upper bounds in the Size box?

[Le Dyk Zuy]

i did, now it says:

Output 'y' has variable size but the upper bound is not specified; explicit upper bound must be provided.

Error in port widths or dimensions. 'Output Port 1' of 'hdl_code_function_test/MATLAB Function/u_port' is a one dimensional vector with 1 elements.