Graph Scene

class manimlib.scene.graph_scene.GraphScene(**kwargs)

Type: Scene

CONFIG parameters

"x_min": -1,
"x_max": 10,
"x_axis_width": 9,
"x_tick_frequency": 1,
"x_leftmost_tick": None,  # Change if different from x_min
"x_labeled_nums": None,
"x_axis_label": "$x$",
"y_min": -1,
"y_max": 10,
"y_axis_height": 6,
"y_tick_frequency": 1,
"y_bottom_tick": None,  # Change if different from y_min
"y_labeled_nums": None,
"y_axis_label": "$y$",
"axes_color": GREY,
"graph_origin": 2.5 * DOWN + 4 * LEFT,
"exclude_zero_label": True,
"num_graph_anchor_points": 25,
"default_graph_colors": [BLUE, GREEN, YELLOW],
"default_derivative_color": GREEN,
"default_input_color": YELLOW,
"default_riemann_start_color": BLUE,
"default_riemann_end_color": GREEN,
"area_opacity": 0.8,
"num_rects": 50,

get_graph(func, color=None, x_min=None, x_max=None)

Parameters

• func (Function) -- This function must be continuous

• color (Hexadecimal color) -- Color

• x_min (float) -- TODO

• x_max (float) -- TODO

get_riemann_rectangles(graph, x_min=None, x_max=None, dx=0.1, input_sample_type='left', stroke_width=1, stroke_color='#000000', fill_opacity=1, start_color=None, end_color=None, show_signed_area=True, width_scale_factor=1.001)

Riemman rectangles.

Parameters

• graph (VMobject) -- Graph from get_graph

• x_min (float) -- TODO

• x_max (float) -- TODO

• dx (float) -- TODO

• input_sample_type (str) -- Can be "left", "center", "right"

get_riemann_rectangles_list(graph, n_iterations, max_dx=0.5, power_base=2, stroke_width=1, **kwargs)

Parameters

• graph (VMobject) -- Graph from get_graph

• n_iterations (int) -- TODO

• max_dx (float) -- TODO

• power_base (int) -- TODO

setup()

This is meant to be implement by any scenes which are comonly subclassed, and have some common setup involved before the construct method is called.

Riemann rectangles

class RiemannRectangles(GraphScene):
    CONFIG = {
        "y_max": 8,
        "y_axis_height": 5,
    }
    def construct(self):
        self.setup_axes()
        def func(x):
            return 0.1 * (x + 3-5) * (x - 3-5) * (x-5) + 5

        graph=self.get_graph(func,x_min=0.3,x_max=9.2)
        riemann_rectangles=self.get_riemann_rectangles(
                                    graph,
                                    x_min=2,
                                    x_max=8,
                                    dx=0.5
                                    )
        self.add(graph,riemann_rectangles)

Riemann rectangles animation

class RiemannRectanglesAnimation(GraphScene):
    CONFIG = {
        "y_max": 8,
        "y_axis_height": 5,
        "init_dx":0.5,
    }
    def construct(self):
        self.setup_axes()
        def func(x):
            return 0.1 * (x + 3-5) * (x - 3-5) * (x-5) + 5

        graph=self.get_graph(func,x_min=0.3,x_max=9.2)
        kwargs = {
            "x_min" : 2,
            "x_max" : 8,
            "fill_opacity" : 0.75,
            "stroke_width" : 0.25,
        }
        flat_rectangles = self.get_riemann_rectangles(
                                self.get_graph(lambda x : 0),
                                dx=self.init_dx,
                                start_color=invert_color(PURPLE),
                                end_color=invert_color(ORANGE),
                                **kwargs
        )
        riemann_rectangles_list = self.get_riemann_rectangles_list(
                                graph,
                                6,
                                max_dx=self.init_dx,
                                power_base=2,
                                start_color=PURPLE,
                                end_color=ORANGE,
                                 **kwargs
        )
        self.add(graph)
        # Show Riemann rectangles
        self.play(ReplacementTransform(flat_rectangles,riemann_rectangles_list[0]))
        self.wait()
        for r in range(1,len(riemann_rectangles_list)):
            self.transform_between_riemann_rects(
                    riemann_rectangles_list[r-1],
                    riemann_rectangles_list[r],
                    replace_mobject_with_target_in_scene = True,
                )
        self.wait()