How to produce an 'if else' loop with an x starting at 1 and increasing to 3 by 1 at each end of the loop

x = [1:1:3];

if x == 2; f2 = inf elseif x > 2; f2 = NaN else f2 = log(5/2-x) end

I'm trying to input a value of x = 1, then x = 2, then x = 3 to get three different answers

[Roger Stafford]

You will get a complex answer for that third case of log(5/2-3) since you are taking the logarithm of a negative number.

Answer 1

[KSSV]

if x == 1; 
    f2 = inf 
elseif x == 2; 
    f2 = NaN 
elseif x ==3
    f2 = log(5/2-x) 
end

As Roger Stafford said, third case will be complex.