[Python] Matplotlib: How does it work and why does it only show the positive x-axis?...

I have code where I want the user to be able to give a function, which will then be graphed with Matplotlib. So I look up online how Matplotlib works, and I end up with this code:

framegraph = Frame(master=window)
fig = Figure(figsize = (5, 5), dpi = 100)
y = [x**2 for x in range(101)]
plot1 = fig.add_subplot(111)
plot1.plot(y)
canvas = FigureCanvasTkAgg(fig, master = framegraph)
canvas.draw()
canvas.get_tk_widget().pack()
toolbar = NavigationToolbar2Tk(canvas, framegraph)
toolbar.update()
canvas.get_tk_widget().pack()
framegraph.grid(row=0, column=0,padx=10, pady=10)

def update():
global entryfunc, canvas, plot1, framegraph, window, y
x = var('x')
func = entryfunc.get()
func = sympify(func)
y = [func.subs(x, z) for z in range(101)]
plot1.clear()
plot1.plot(y)
canvas.draw()
canvas.get_tk_widget().pack()


And it works well, except, the graph looks like this:

Graph output

It's the squared function, so it should also be graphed on the negative x-axis, but I cannot figure out how to do it.

Continue reading...