fprintf Displays the wrong value

The following command returns the wrong value when using the command:

fprintf('\ny = %1.2f\n\n',y);

Enter a value for x: 5

y = 45.00

y = 52.00

Here is the code:

    clear all; clc

    x = input('Enter a value for x: ');

    if x == -2 || x == -6 || x == -4;
        y = '3';
    elseif x == 2;
        y = '0';
    else
        error('Error');
    end

    clc

    % display(y);

    fprintf('\ny = %1.2f\n\n',y);

Answer 1

[Image Analyst]

You're setting y equal to a character string but using %1.2f (which doesn't make sense even if y were a double) instead of %s to display a character string. So it displays the ASCII values of the string. Instead of

y = '0'; % y is a character.

and so on, try

y = 0;  % y is a double.

and use %d to display it, not %1.2f, in your fprintf() call.

[J]

I can't believe I missed that. Thank you.

Answer 2

[Roger Stafford]

You are assigning y string values, not numerical values, but you are displaying them using 'fprintf' for numerical values (%1.2f), so you have to expect strange results. For example the string value of y = '3' has a corresponding numerical value of 51.

Also you have written

   if x == -2 x == -6 x == -4;

but that will not behave as I think you expect. Better read up on the 'if' function to see how to write a valid 'if' condition.

[Image Analyst]

That's what I thought at first, but no, what he really needs to read is this http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup. I went ahead and formatted it properly so that the || show up now.