clear
val scale = 100
def f(x: Double): Double = x * x
runInBackground {
    val t = newTurtle(0, -1 * scale)
    t.moveTo(0, 1 * scale)
}
runInBackground {
    val t = newTurtle(-1 * scale, 0)
    t.moveTo(1 * scale, 0)
}
runInBackground {
    jumpTo(-1 * scale, f(-1) * scale)
    for (n <- -1.0 to 1 by 0.1)
        moveTo(n * scale, f(n) * scale)

}