'Not equal too' statement not working

I have a program that gives the user a 5x5 grid and asks them to click on the stated coordinate. If they respond correctly, a second coordinate is generated. If not, an error message is displayed. A correct response is tested using the following code:

            if UserResponse ~= RequiredCoordinate
                Error.String = 'INCORRECT';                
            else
                Error.String = '';
            end

The problem is that it doesn't always work.

By not suppressing the variables I can see that the values aren't equal, however the code behaves as if they are equal, treating it like a correct response. But this problem only occurs sometimes.

I've run the code on 3 different machines, all running the same version (R2015, 1 machine runs a student license if that makes a difference) and sometimes the code runs as expected and others this problem occurs.

Can anyone suggest a solution?

Thank you.

[Stephen23]

Please give us some values that show this behavior.

[Thorsten]

What is UserResponse? A single number, or two coordinates?

[Jonathan Riley]

Both variables are of type 1x2 double - e.g. [5,3]

[dpb]

Try

~all(UserResponse==RequiredCoordinate)

instead or if the values aren't integers see the FAQ (and will still need the above if is an array of coordinates rather than single value)--

Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero

Answer 1

[dpb]

As noted in the above comment prior to seeing your response...

 >> x=[5,3]; y=[5,2];
>> all(x==y)
ans =
     0
>> y(2)=3;
>> all(x==y)
ans =
     1
>>

Again, note the caution re: floating point comparisons if the values aren't integer; you'll have to use "fuzzy" comparison for a robust test.

Answer 2

[James Tursa]

Another method using the function isequal, which is useful for arrays:

            if ~isequal(UserResponse,RequiredCoordinate)