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from manimlib.imports import *
class IterationMethods(GraphScene):
CONFIG = {
"x_min" : 0,
"x_max" : 1,
"y_min" : 0,
"y_max" : 1,
"x_tick_frequency" : 1,
"y_tick_frequency" : 1,
"x_labeled_nums": list(np.arange(0,2)),
"y_labeled_nums": list(np.arange(0 ,2)),
"x_axis_width": 6,
"y_axis_height": 6,
"graph_origin": ORIGIN+4*LEFT+3*DOWN,
"area_color": PINK ,
"area_opacity": .6,
}
def construct(self):
X = RIGHT*self.x_axis_width/(self.x_max- self.x_min)
Y = UP*self.y_axis_height/(self.y_max- self.y_min)
# self.intro_scene()
self.setup_axes(animate=True)
curve1= self.get_graph(
lambda x : x**2 ,
x_min = 0,
x_max = 1,
color = ORANGE)
c1_eqn=self.get_graph_label(
curve1,
label="y=x^2",
x_val=.5,
direction=RIGHT,
buff=MED_LARGE_BUFF,
color=ORANGE,
)
curve2= self.get_graph(
lambda x : x ,
x_min = 0,
x_max = 1,
color = YELLOW)
c2_eqn=self.get_graph_label(
curve2,
label="y=x",
x_val=.5,
direction=LEFT,
buff=MED_LARGE_BUFF,
color=YELLOW,
)
self.curve1=curve1
self.curve2=curve2
caption_y_int=TextMobject(r"Observe the limits\\ of integration").to_corner(UR)
int_lim=TextMobject(
"$$\\int_0^1$$"
).next_to(
caption_y_int,DOWN,buff=.5
).align_to(
caption_y_int,LEFT
)
self.play(ShowCreation(VGroup(curve1,curve2)),Write(VGroup(c2_eqn,c1_eqn)))
rects=self.get_rects()
self.play(Write(caption_y_int))
self.show_integral_values_at_different_x()
self.wait(1)
self.add(int_lim)
self.play(FadeOut(self.brace_group))
self.play(ApplyMethod(
self.y_int.next_to,
int_lim,RIGHT,buff=0))
self.play(ApplyMethod(
self.dx_label.next_to,
self.y_int,RIGHT))
self.show_area()
self.wait(2)
###################
def intro_scene(self):
text=TextMobject(r"How different orders of \textbf{iterated integral}\\ works over the same region ?" )
self.play(Write(text),run_time=4)
self.wait(2)
self.play(FadeOut(text))
def show_area(self):
area = self.bounded_riemann_rectangles(
self.curve1,
self.curve2,
x_min = 0,
x_max = 1,
dx =.001,
start_color = self.area_color,
end_color = self.area_color,
fill_opacity = 1,
stroke_width = 0,
)
self.play(ShowCreation(area))
# self.transform_between_riemann_rects(self.rects,area)
self.area = area
def get_rects(self):
rects = self.bounded_riemann_rectangles(
self.curve1,
self.curve2,
x_min = 0,
x_max = 1,
dx =.01,
start_color = self.area_color,
end_color = self.area_color,
fill_opacity =self.area_opacity,
stroke_width = 0,
)
# self.transform_between_riemann_rects(self.area,rects)
self.rects=rects
return rects
def show_integral_values_at_different_x(self):
rects=self.rects
rect = rects[len(rects)*1//10]
dx_brace = Brace(rect, DOWN, buff = 0)
dx_label = dx_brace.get_text("$dx$", buff = SMALL_BUFF)
dx_brace_group = VGroup(dx_brace,dx_label)
rp=int(len(rects)/10)
rects_subset = self.rects[4*rp:5*rp]
last_rect = None
for rect in rects_subset:
brace = Brace(rect, LEFT, buff =.1)
y_int = TexMobject("\\int_{x^2}^{x}dy")#.rotate(PI/2)
y_int.next_to(brace, LEFT, MED_SMALL_BUFF)
anims = [
rect.set_fill, self.area_color, 1,
dx_brace_group.next_to, rect, DOWN, SMALL_BUFF
]
if last_rect is not None:
anims += [
last_rect.set_fill, None, 0,
# last_rect.set_fill, self.area_color, self.area_opacity,
ReplacementTransform(last_brace, brace),
ReplacementTransform(last_y_int, y_int),
]
else:
anims += [
GrowFromCenter(brace),
Write(y_int)
]
self.play(*anims)
# self.wait(.2)
last_rect = rect
last_brace = brace
last_y_int = y_int
y_int = last_y_int
y_brace = last_brace
self.brace_group=VGroup(y_brace,dx_brace,rect)
self.y_int=y_int
self.dx_label=dx_label
def bounded_riemann_rectangles(
self,
graph1,
graph2,
x_min=None,
x_max=None,
dx=0.01,
input_sample_type="center",
stroke_width=1,
stroke_color=BLACK,
fill_opacity=1,
start_color=None,
end_color=None,
show_signed_area=True,
width_scale_factor=1.001
):
x_min = x_min if x_min is not None else self.x_min
x_max = x_max if x_max is not None else self.x_max
if start_color is None:
start_color = self.default_riemann_start_color
if end_color is None:
end_color = self.default_riemann_end_color
rectangles = VGroup()
x_range = np.arange(x_min, x_max, dx)
colors = color_gradient([start_color, end_color], len(x_range))
for x, color in zip(x_range, colors):
if input_sample_type == "left":
sample_input = x
elif input_sample_type == "right":
sample_input = x + dx
elif input_sample_type == "center":
sample_input = x + 0.5 * dx
else:
raise Exception("Invalid input sample type")
graph1_point = self.input_to_graph_point(sample_input, graph1)
graph1_point_dx= self.input_to_graph_point(sample_input + width_scale_factor * dx, graph1)
graph2_point = self.input_to_graph_point(sample_input, graph2)
points = VGroup(*list(map(VectorizedPoint, [
graph1_point,
graph1_point_dx,
graph2_point
])))
rect = Rectangle()
rect.replace(points, stretch=True)
if graph1_point[1] < self.graph_origin[1] and show_signed_area:
fill_color = invert_color(color)
else:
fill_color = color
rect.set_fill(fill_color, opacity=fill_opacity)
rect.set_stroke(stroke_color, width=stroke_width)
rectangles.add(rect)
return rectangles
#uploaded by Somnath Pandit.FSF2020_Fubini's_Theorem
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