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ManimML/manim_ml/decision_tree/decision_tree.py

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16 KiB
Python

"""
Module for visualizing decision trees in Manim.
It parses a decision tree classifier from sklearn.
TODO return a map from nodes to split animation for BFS tree expansion
TODO reimplement the decision 2D decision tree surface drawing.
"""
from manim import *
from manim_ml.decision_tree.classification_areas import compute_decision_areas, merge_overlapping_polygons
import manim_ml.decision_tree.helpers as helpers
from manim_ml.one_to_one_sync import OneToOneSync
import numpy as np
from PIL import Image
class LeafNode(Group):
"""Leaf node in tree"""
def __init__(self, class_index, display_type="image", class_image_paths=[],
class_colors=[]):
super().__init__()
self.display_type = display_type
self.class_image_paths = class_image_paths
self.class_colors = class_colors
assert self.display_type in ["image", "text"]
if self.display_type == "image":
self._construct_image_node(class_index)
else:
raise NotImplementedError()
def _construct_image_node(self, class_index):
"""Make an image node"""
# Get image
image_path = self.class_image_paths[class_index]
pil_image = Image.open(image_path)
node = ImageMobject(pil_image)
node.scale(1.5)
rectangle = Rectangle(
width=node.width + 0.05,
height=node.height + 0.05,
color=self.class_colors[class_index],
stroke_width=6
)
rectangle.move_to(node.get_center())
rectangle.shift([-0.02, 0.02, 0])
self.add(rectangle)
self.add(node)
class SplitNode(VGroup):
"""Node for splitting decision in tree"""
def __init__(self, feature, threshold):
super().__init__()
node_text = f"{feature}\n<= {threshold:.2f} cm"
# Draw decision text
decision_text = Text(
node_text,
color=WHITE
)
# Draw the surrounding box
bounding_box = SurroundingRectangle(
decision_text,
buff=0.3,
color=WHITE
)
self.add(bounding_box)
self.add(decision_text)
class DecisionTreeDiagram(Group):
"""Decision Tree Diagram Class for Manim"""
def __init__(self, sklearn_tree, feature_names=None,
class_names=None, class_images_paths=None,
class_colors=[RED, GREEN, BLUE]):
super().__init__()
self.tree = sklearn_tree
self.feature_names = feature_names
self.class_names = class_names
self.class_image_paths = class_images_paths
self.class_colors = class_colors
# Make graph container for the tree
self.tree_group, self.nodes_map, self.edge_map = self._make_tree()
self.add(self.tree_group)
def _make_node(
self,
node_index,
):
"""Make node"""
is_split_node = self.tree.children_left[node_index] != self.tree.children_right[node_index]
if is_split_node:
node_feature = self.tree.feature[node_index]
node_threshold = self.tree.threshold[node_index]
node = SplitNode(
self.feature_names[node_feature],
node_threshold
)
else:
# Get the most abundant class for the given leaf node
# Make the leaf node object
tree_class_index = np.argmax(self.tree.value[node_index])
node = LeafNode(
class_index=tree_class_index,
class_colors=self.class_colors,
class_image_paths=self.class_image_paths
)
return node
def _make_connection(self, top, bottom, is_leaf=False):
"""Make a connection from top to bottom"""
top_node_bottom_location = top.get_center()
top_node_bottom_location[1] -= top.height / 2
bottom_node_top_location = bottom.get_center()
bottom_node_top_location[1] += bottom.height / 2
line = Line(
top_node_bottom_location,
bottom_node_top_location,
color=WHITE
)
return line
def _make_tree(self):
"""Construct the tree diagram"""
tree_group = Group()
max_depth = self.tree.max_depth
# Make the root node
nodes_map = {}
root_node = self._make_node(
node_index=0,
)
nodes_map[0] = root_node
tree_group.add(root_node)
# Save some information
node_height = root_node.height
node_width = root_node.width
scale_factor = 1.0
edge_map = {}
# tree height
tree_height = scale_factor * node_height * max_depth
tree_width = scale_factor * 2 ** max_depth * node_width
# traverse tree
def recurse(node_index, depth, direction, parent_object, parent_node):
# make the node object
is_leaf = self.tree.children_left[node_index] == self.tree.children_right[node_index]
node_object = self._make_node(node_index=node_index)
nodes_map[node_index] = node_object
node_height = node_object.height
# set the node position
direction_factor = -1 if direction == "left" else 1
shift_right_amount = 0.9 * direction_factor * scale_factor * tree_width / (2 ** depth) / 2
if is_leaf:
shift_down_amount = -1.0 * scale_factor * node_height
else:
shift_down_amount = -1.8 * scale_factor * node_height
node_object \
.match_x(parent_object) \
.match_y(parent_object) \
.shift([shift_right_amount, shift_down_amount, 0])
tree_group.add(node_object)
# make a connection
connection = self._make_connection(parent_object, node_object, is_leaf=is_leaf)
edge_name = str(parent_node)+","+str(node_index)
edge_map[edge_name] = connection
tree_group.add(connection)
# recurse
if not is_leaf:
recurse(self.tree.children_left[node_index], depth + 1, "left", node_object, node_index)
recurse(self.tree.children_right[node_index], depth + 1, "right", node_object, node_index)
recurse(self.tree.children_left[0], 1, "left", root_node, 0)
recurse(self.tree.children_right[0], 1, "right", root_node, 0)
tree_group.scale(0.35)
return tree_group, nodes_map, edge_map
def create_level_order_expansion_decision_tree(self, tree):
"""Expands the decision tree in level order"""
raise NotImplementedError()
def create_bfs_expansion_decision_tree(self, tree):
"""Expands the tree using BFS"""
animations = []
# Compute parent mapping
parent_mapping = helpers.compute_node_to_parent_mapping(self.tree)
# Create the root node
animations.append(
Create(self.nodes_map[0])
)
# Iterate through the nodes
queue = [0]
while len(queue) > 0:
node_index = queue.pop(0)
# Check if a node is a split node or not
left_child = self.tree.children_left[node_index]
right_child = self.tree.children_right[node_index]
is_leaf_node = left_child == right_child
if not is_leaf_node:
# Split the node by creating the children and connecting them
# to the parent
# Get the nodes
left_node = self.nodes_map[left_child]
right_node = self.nodes_map[right_child]
# Get the parent edges
left_parent_edge = self.edge_map[f"{node_index},{left_child}"]
right_parent_edge = self.edge_map[f"{node_index},{right_child}"]
# Create the children
split_animation = AnimationGroup(
FadeIn(left_node),
FadeIn(right_node),
Create(left_parent_edge),
Create(right_parent_edge),
lag_ratio=0.0
)
animations.append(
split_animation
)
# Add the children to the queue
if left_child != -1:
queue.append(left_child)
if right_child != -1:
queue.append(right_child)
return AnimationGroup(
*animations,
lag_ratio=1.0
)
@override_animation(Create)
def create_decision_tree(self, traversal_order="bfs"):
"""Makes a create animation for the decision tree"""
if traversal_order == "level":
return self.create_level_order_expansion_decision_tree(self.tree)
elif traversal_order == "bfs":
return self.create_bfs_expansion_decision_tree(self.tree)
else:
raise Exception(f"Uncrecognized traversal: {traversal_order}")
class IrisDatasetPlot(VGroup):
def __init__(self, iris):
points = iris.data[:, 0:2]
labels = iris.feature_names
targets = iris.target
# Make points
self.point_group = self._make_point_group(points, targets)
# Make axes
self.axes_group = self._make_axes_group(points, labels)
# Make legend
self.legend_group = self._make_legend(
[BLUE, ORANGE, GREEN],
iris.target_names,
self.axes_group
)
# Make title
#title_text = "Iris Dataset Plot"
#self.title = Text(title_text).match_y(self.axes_group).shift([0.5, self.axes_group.height / 2 + 0.5, 0])
# Make all group
self.all_group = Group(
self.point_group,
self.axes_group,
self.legend_group
)
# scale the groups
self.point_group.scale(1.6)
self.point_group.match_x(self.axes_group)
self.point_group.match_y(self.axes_group)
self.point_group.shift([0.2, 0, 0])
self.axes_group.scale(0.7)
self.all_group.shift([0, 0.2, 0])
@override_animation(Create)
def create_animation(self):
animation_group = AnimationGroup(
# Perform the animations
Create(self.point_group, run_time=2),
Wait(0.5),
Create(self.axes_group, run_time=2),
# add title
#Create(self.title),
Create(self.legend_group)
)
return animation_group
def _make_point_group(self, points, targets, class_colors=[BLUE, ORANGE, GREEN]):
point_group = VGroup()
for point_index, point in enumerate(points):
# draw the dot
current_target = targets[point_index]
color = class_colors[current_target]
dot = Dot(point=np.array([point[0], point[1], 0])).set_color(color)
dot.scale(0.5)
point_group.add(dot)
return point_group
def _make_legend(self, class_colors, feature_labels, axes):
legend_group = VGroup()
# Make Text
setosa = Text("Setosa", color=BLUE)
verisicolor = Text("Verisicolor", color=ORANGE)
virginica = Text("Virginica", color=GREEN)
labels = VGroup(setosa, verisicolor, virginica).arrange(direction=RIGHT, aligned_edge=LEFT, buff=2.0)
labels.scale(0.5)
legend_group.add(labels)
# surrounding rectangle
surrounding_rectangle = SurroundingRectangle(labels, color=WHITE)
surrounding_rectangle.move_to(labels)
legend_group.add(surrounding_rectangle)
# shift the legend group
legend_group.move_to(axes)
legend_group.shift([0, -3.0, 0])
legend_group.match_x(axes[0][0])
return legend_group
def _make_axes_group(self, points, labels, font='Source Han Sans', font_scale=0.75):
axes_group = VGroup()
# make the axes
x_range = [np.amin(points, axis=0)[0] - 0.2, np.amax(points, axis=0)[0] - 0.2, 0.5]
y_range = [np.amin(points, axis=0)[1] - 0.2, np.amax(points, axis=0)[1], 0.5]
axes = Axes(
x_range=x_range,
y_range=y_range,
x_length=9,
y_length=6.5,
# axis_config={"number_scale_value":0.75, "include_numbers":True},
tips=False,
).shift([0.5, 0.25, 0])
axes_group.add(axes)
# make axis labels
# x_label
x_label = Text(labels[0], font=font) \
.match_y(axes.get_axes()[0]) \
.shift([0.5, -0.75, 0]) \
.scale(font_scale)
axes_group.add(x_label)
# y_label
y_label = Text(labels[1], font=font) \
.match_x(axes.get_axes()[1]) \
.shift([-0.75, 0, 0]) \
.rotate(np.pi / 2) \
.scale(font_scale)
axes_group.add(y_label)
return axes_group
class DecisionTreeSurface(VGroup):
def __init__(self, tree_clf, data, axes, class_colors=[BLUE, ORANGE, GREEN]):
# take the tree and construct the surface from it
self.tree_clf = tree_clf
self.data = data
self.axes = axes
self.class_colors = class_colors
self.surface_rectangles = self.generate_surface_rectangles()
def generate_surface_rectangles(self):
# compute data bounds
left = np.amin(self.data[:, 0]) - 0.2
right = np.amax(self.data[:, 0]) - 0.2
top = np.amax(self.data[:, 1])
bottom = np.amin(self.data[:, 1]) - 0.2
maxrange = [left, right, bottom, top]
rectangles = compute_decision_areas(
self.tree_clf,
maxrange,
x=0,
y=1,
n_features=2
)
# turn the rectangle objects into manim rectangles
def convert_rectangle_to_polygon(rect):
# get the points for the rectangle in the plot coordinate frame
bottom_left = [rect[0], rect[3]]
bottom_right = [rect[1], rect[3]]
top_right = [rect[1], rect[2]]
top_left = [rect[0], rect[2]]
# convert those points into the entire manim coordinates
bottom_left_coord = self.axes.coords_to_point(*bottom_left)
bottom_right_coord = self.axes.coords_to_point(*bottom_right)
top_right_coord = self.axes.coords_to_point(*top_right)
top_left_coord = self.axes.coords_to_point(*top_left)
points = [bottom_left_coord, bottom_right_coord, top_right_coord, top_left_coord]
# construct a polygon object from those manim coordinates
rectangle = Polygon(*points, color=color, fill_opacity=0.3, stroke_opacity=0.0)
return rectangle
manim_rectangles = []
for rect in rectangles:
color = self.class_colors[int(rect[4])]
rectangle = convert_rectangle_to_polygon(rect)
manim_rectangles.append(rectangle)
manim_rectangles = merge_overlapping_polygons(manim_rectangles, colors=[BLUE, GREEN, ORANGE])
return manim_rectangles
@override_animation(Create)
def create_override(self):
# play a reveal of all of the surface rectangles
animations = []
for rectangle in self.surface_rectangles:
animations.append(Create(rectangle))
animation_group = AnimationGroup(*animations)
return animation_group
@override_animation(Uncreate)
def uncreate_override(self):
# play a reveal of all of the surface rectangles
animations = []
for rectangle in self.surface_rectangles:
animations.append(Uncreate(rectangle))
animation_group = AnimationGroup(*animations)
return animation_group
class DecisionTreeContainer(OneToOneSync):
"""Connects the DecisionTreeDiagram to the DecisionTreeEmbedding"""
def __init__(self, sklearn_tree, points, classes):
self.sklearn_tree = sklearn_tree
self.points = points
self.classes = classes
def make_unfold_tree_animation(self):
"""Unfolds the tree through an in order traversal
This animations unfolds the tree diagram as well as showing the splitting
of a shaded region in the Decision Tree embedding.
"""
# Draw points in the embedding
# Start the tree splitting animation
pass