Output argument 'check_equal' is not assigned on some execution paths

This is the main function

Main_algo.m

x=7;

y=7;

check_equal_case(x,y)

it is called from function: check_equal_case.m

function check_equal=check_equal_case(x,y)

if (x==y)

final_seq = ones(1,y)

end

compilation is correct in matlab script.

when try to generate c ++ code, matlab throws error : Output argument 'check_equal' is not assigned on some execution paths

please help.

[Stephen23]

What do you expect the output to be if x does not equal y ?

[anshuman mishra]

no output message.

Answer 1

[Darshan Ramakant Bhat]

This is because output variable should have a value in each execution branch. Otherwise MATLAB Coder compiler will not be able to determine the value of the output when that branch is taken.

One potential soution for this issue is to initialize the output variable at the beginning of the function :

function check_equal=check_equal_case(x,y)
check_equal = false;
 if (x==y)
         final_seq = ones(1,y)     
 end
end

If the output variable is changing it's size in some of the branches, then you can make use of coder.varsize :

function [x,y] = usevarsize(n)
%#codegen
x = 1;
coder.varsize('x');
y = size(x);
if n > 10
    x = 1:10;
end

Hope this will help you.