Output argument "variable" (and maybe others) not assigned during call to "function".

I'm new to MATLAB and have created a simple function. However, matlab shows me the following error: Output argument "val" (and maybe others) not assigned during call to "u".

Here is the code:

function val = f(n)
  val = u(n) - u(n - 4);
end

Here is u(x):

function val = u(x)

    if x < 0 
         val = 0;   
    end

    if x == 0
        val = 0.5;
    end

    if x > 1
        val = 1;
    end
end

[Stephen23]

The possibility that x is non-scalar should also be considered. This code would be much improved by being written completely vectorized.

Answer 1

[James Tursa]

Your code is calling a function named "u" and that function is not returning a value, so nothing gets assigned to val. What does the code for your "u" function look like? Or is "u" supposed to be a variable?

EDIT:

Your "u" function does not assign anything to the val output if the input x is between 0 and 1. So maybe you need to make that last test

if( x > 0 )

[Satyam Singh]

Ahh, it was supposed to be x>0 only..Oops.. It solved my problem thanks a lot!