Why am I getting an NaN value for my array?

n5 = [-5:5];
y0 = abs(Dn2f(0))

y0 = 0.5000

ys = abs(Dn2f(n5))

ys = 1×11

0.0900 0.0000 0.1501 0.3183 0.4502 NaN 0.4502 0.3183 0.1501 0.0000 0.0900

function Dn = Dn2f(n)
    if n == 0
       Dn = 1/2;
    else
       Dn = (1-exp(-1j*pi*n/2))./(1j*pi*n);
    end
end

I specifically defined the value of my function at 0 because of a division by 0, and it even returns the correct value at 0 when I call it for a single value, but in an array, the value at 0 is NaN?

Answer 1

[Walter Roberson]

In MATLAB if you test a non-scalar in an "if" statement, then the statement is considered true only if all of the outputs of the expression are non-zero. "if" does not act as a selector to only work on the elements that the test is true for.

You should learn how to use logical indexing.