Pass a structure to a function...

Hello, I crated a structure

>> A(1).vect=[1 2 3 4]';
>> A(2).vect=[4 5 2 1]';
>> A(3).vect=[7 5 3 8]';

And I wrote a function to find average of vectors which are in this "A.vect" structure. And stored in a separate .m file with the same name avg_fun.m

%-------------------------------------
function [avg]=avg_fun(X,no_of_vect)

avg=0;
for i=1:no_of_vect
avg=avg+(X(1,i));
end

avg=avg/nofv;
%-------------------------------------

Then I tried my test:

>>avg_fun(A.vect,3)

Error showing:

Function definitions are not permitted at the prompt or
in scripts.

My doubt here is: How to pass a structure to a funtion ? What I have written in the funtion arguments

function [avg]=avg_fun(X,no_of_vect)

is correct ? (i.e writing X is correct ?)

Expecting right answer... And right code...

Answer 1

[Andrew Newell]

You seem to have a number of problems here. First, you need to save the function to a separate file called avg_fun.m. Second, you need to pass the structure rather than its subfield because A.vect is interpreted as three inputs. Third, you are normalizing by the undefined variable nofv, which should be no_of_vect.

Here is the corrected function:

function [avg]=avg_fun(X,no_of_vect)

avg=0; 

for i=1:no_of_vect 
    avg=avg+(X(1,i).vect); 
end

avg=avg/no_of_vect;

and here is the script to call it:

A(1).vect=[1 2 3 4]';
A(2).vect=[4 5 2 1]';
A(3).vect=[7 5 3 8]';

avg_fun(A,3)

EDIT: You could also use a built-in function to do this:

mean([A.vect],2)

This collects the vectors into a matrix and sums across each row.

Answer 2

[Raviteja]

Dear Andrew,

Thank you very very much! Iam struggling from 2 days!

Your guidance helped me a lot!

[Andrew Newell]

Glad to help.