[Gnuplot-info] Step function not starting at absolute 0

[GOO C. <goo...@gm...>]

Hi all,

I'm trying to create a simple step function. I have this weird problem 
that the x-values of my function do not start at absolute 0, therefore 
creating a skew function. Here is my code:

    /set xzeroaxis lc "black"//
    //set yzeroaxis lc "black"//
    //set terminal pdf//
    //set output "step.pdf"//
    //f(x)= x <= 0 ? -1 : 1//
    //plot f(x) lw 2 lc "black"//
    /


I've also attached the output PDF. As you can see the middle part of the 
function is not parrallel with the y-axis. Does anyone know what I'm missing

Chris