Is there an efficient way to graph the imaginary outputs of y for the real in puts of x (a 3D graph)? I would prefer to use free software such as Maxima, Octave or Sage online, but if necessary I am willing to invest in Maple, Mathcad, or Mathematica.
Sincerely,
Joe Hobbit
Depends on if you include the real parts as well or not. But both are easy,
$(x,realpart(y),imagpart(y))$ will work for maxima for graphing the real part of $y$ on the second axis and the imaginary part on the third (I don't know the notation for functions with three outputs, but realpart and imagpart will give you the real and imaginary parts).
If you don't want the imaginary part, just do $(x,realpart(y))$.
I may not have answered your entire question; if so, just mention it and me or someone else will answer the rest.
Edit: The graph in the onion your comments is a very exceptional graph which is generally not achievable; the xy plane is a single complex variable, while the z axis is a real output. They only graphed $t^2+t+1$ on two lines in the xy plane because those two planes are the only places where the output is real. It would be impossible to graph what happens over the imaginary y-axis in the same picture.
Edit 2: The following wolfram alpha equation plots a function with complex outputs and real inputs. It plots the complex output values as the y and z coordinates and the real input as the x coordinate. The function is $e^{it}$.
parametric plot (t,re(e^(it)),im(e^(it))) -12...12
Alternatively, you can plot just the real part or just the imaginary part of a function with a complex input and a complex output:
plot Re((x+iy)^2+x+iy+1) for the real part and plot Im((x+iy)^2+x+iy+1) for the imaginary part.
To get the exact picture you had in that link, you would input
parametric plot (t,0,t^2+t+1) and parametric plot (-1/2,t,(-1+it)^2+(-1+it)+1) and try to get them on the same window.