def main():
    x, y, z = symbols('x,y,z')

    # toggle axes visibility with F5, colors with F6
    axes_options = 'visible=false; colored=true; label_ticks=true; label_axes=true; overlay=true; stride=0.5'
    # axes_options = 'colored=false; overlay=false; stride=(1.0, 0.5, 0.5)'

    p = PygletPlot(
        width=600,
        height=500,
        ortho=False,
        invert_mouse_zoom=False,
        axes=axes_options,
        antialiasing=True)

    examples = []

    def example_wrapper(f):
        examples.append(f)
        return f

    @example_wrapper
    def mirrored_saddles():
        p[5] = x**2 - y**2, [20], [20]
        p[6] = y**2 - x**2, [20], [20]

    @example_wrapper
    def mirrored_saddles_saveimage():
        p[5] = x**2 - y**2, [20], [20]
        p[6] = y**2 - x**2, [20], [20]
        p.wait_for_calculations()
        # although the calculation is complete,
        # we still need to wait for it to be
        # rendered, so we'll sleep to be sure.
        sleep(1)
        p.saveimage("plot_example.png")

    @example_wrapper
    def mirrored_ellipsoids():
        p[2] = x**2 + y**2, [40], [40], 'color=zfade'
        p[3] = -x**2 - y**2, [40], [40], 'color=zfade'

    @example_wrapper
    def saddle_colored_by_derivative():
        f = x**2 - y**2
        p[1] = f, 'style=solid'
        p[1].color = abs(f.diff(x)), abs(f.diff(x) + f.diff(y)), abs(f.diff(y))

    @example_wrapper
    def ding_dong_surface():
        f = sqrt(1.0 - y)*y
        p[1] = f, [x, 0, 2*pi,
                   40], [y, -
                             1, 4, 100], 'mode=cylindrical; style=solid; color=zfade4'

    @example_wrapper
    def polar_circle():
        p[7] = 1, 'mode=polar'

    @example_wrapper
    def polar_flower():
        p[8] = 1.5*sin(4*x), [160], 'mode=polar'
        p[8].color = z, x, y, (0.5, 0.5, 0.5), (
            0.8, 0.8, 0.8), (x, y, None, z)  # z is used for t

    @example_wrapper
    def simple_cylinder():
        p[9] = 1, 'mode=cylindrical'

    @example_wrapper
    def cylindrical_hyperbola():
        # (note that polar is an alias for cylindrical)
        p[10] = 1/y, 'mode=polar', [x], [y, -2, 2, 20]

    @example_wrapper
    def extruded_hyperbolas():
        p[11] = 1/x, [x, -10, 10, 100], [1], 'style=solid'
        p[12] = -1/x, [x, -10, 10, 100], [1], 'style=solid'

    @example_wrapper
    def torus():
        a, b = 1, 0.5  # radius, thickness
        p[13] = (a + b*cos(x))*cos(y), (a + b*cos(x)) *\
            sin(y), b*sin(x), [x, 0, pi*2, 40], [y, 0, pi*2, 40]

    @example_wrapper
    def warped_torus():
        a, b = 2, 1  # radius, thickness
        p[13] = (a + b*cos(x))*cos(y), (a + b*cos(x))*sin(y), b *\
            sin(x) + 0.5*sin(4*y), [x, 0, pi*2, 40], [y, 0, pi*2, 40]

    @example_wrapper
    def parametric_spiral():
        p[14] = cos(y), sin(y), y / 10.0, [y, -4*pi, 4*pi, 100]
        p[14].color = x, (0.1, 0.9), y, (0.1, 0.9), z, (0.1, 0.9)

    @example_wrapper
    def multistep_gradient():
        p[1] = 1, 'mode=spherical', 'style=both'
        # p[1] = exp(-x**2-y**2+(x*y)/4), [-1.7,1.7,100], [-1.7,1.7,100], 'style=solid'
        # p[1] = 5*x*y*exp(-x**2-y**2), [-2,2,100], [-2,2,100]
        gradient = [0.0, (0.3, 0.3, 1.0),
                    0.30, (0.3, 1.0, 0.3),
                    0.55, (0.95, 1.0, 0.2),
                    0.65, (1.0, 0.95, 0.2),
                    0.85, (1.0, 0.7, 0.2),
                    1.0, (1.0, 0.3, 0.2)]
        p[1].color = z, [None, None, z], gradient
        # p[1].color = 'zfade'
        # p[1].color = 'zfade3'

    @example_wrapper
    def lambda_vs_sympy_evaluation():
        start = clock()
        p[4] = x**2 + y**2, [100], [100], 'style=solid'
        p.wait_for_calculations()
        print("lambda-based calculation took %s seconds." % (clock() - start))

        start = clock()
        p[4] = x**2 + y**2, [100], [100], 'style=solid; use_sympy_eval'
        p.wait_for_calculations()
        print(
            "sympy substitution-based calculation took %s seconds." %
            (clock() - start))

    @example_wrapper
    def gradient_vectors():
        def gradient_vectors_inner(f, i):
            from sympy import lambdify
            from sympy.plotting.plot_interval import PlotInterval
            from pyglet.gl import glBegin, glColor3f
            from pyglet.gl import glVertex3f, glEnd, GL_LINES

            def draw_gradient_vectors(f, iu, iv):
                """
                Create a function which draws vectors
                representing the gradient of f.
                """
                dx, dy, dz = f.diff(x), f.diff(y), 0
                FF = lambdify([x, y], [x, y, f])
                FG = lambdify([x, y], [dx, dy, dz])
                iu.v_steps /= 5
                iv.v_steps /= 5
                Gvl = list(list([FF(u, v), FG(u, v)]
                                for v in iv.frange())
                           for u in iu.frange())

                def draw_arrow(p1, p2):
                    """
                    Draw a single vector.
                    """
                    glColor3f(0.4, 0.4, 0.9)
                    glVertex3f(*p1)

                    glColor3f(0.9, 0.4, 0.4)
                    glVertex3f(*p2)

                def draw():
                    """
                    Iterate through the calculated
                    vectors and draw them.
                    """
                    glBegin(GL_LINES)
                    for u in Gvl:
                        for v in u:
                            point = [[v[0][0], v[0][1], v[0][2]],
                                     [v[0][0] + v[1][0], v[0][1] + v[1][1], v[0][2] + v[1][2]]]
                            draw_arrow(point[0], point[1])
                    glEnd()

                return draw
            p[i] = f, [-0.5, 0.5, 25], [-0.5, 0.5, 25], 'style=solid'
            iu = PlotInterval(p[i].intervals[0])
            iv = PlotInterval(p[i].intervals[1])
            p[i].postdraw.append(draw_gradient_vectors(f, iu, iv))

        gradient_vectors_inner(x**2 + y**2, 1)
        gradient_vectors_inner(-x**2 - y**2, 2)

    def help_str():
        s = ("\nPlot p has been created. Useful commands: \n"
             "    help(p), p[1] = x**2, print p, p.clear() \n\n"
             "Available examples (see source in plotting.py):\n\n")
        for i in range(len(examples)):
            s += "(%i) %s\n" % (i, examples[i].__name__)
        s += "\n"
        s += "e.g. >>> example(2)\n"
        s += "     >>> ding_dong_surface()\n"
        return s

    def example(i):
        if callable(i):
            p.clear()
            i()
        elif i >= 0 and i < len(examples):
            p.clear()
            examples[i]()
        else:
            print("Not a valid example.\n")
        print(p)

    example(0)  # 0 - 15 are defined above
    print(help_str())
dataset/ETHPy150Open sympy/sympy/examples/advanced/pyglet_plotting.py/main/original