Source code for manim.mobject.graphing.probability

"""Mobjects representing objects from probability theory and statistics."""

from __future__ import annotations

__all__ = ["SampleSpace", "BarChart"]

from typing import Iterable, MutableSequence, Sequence

import numpy as np

from manim import config, logger
from manim.constants import *
from manim.mobject.geometry.polygram import Rectangle
from manim.mobject.graphing.coordinate_systems import Axes
from manim.mobject.mobject import Mobject
from manim.mobject.opengl.opengl_mobject import OpenGLMobject
from manim.mobject.svg.brace import Brace
from manim.mobject.text.tex_mobject import MathTex, Tex
from manim.mobject.types.vectorized_mobject import VGroup, VMobject
from manim.utils.color import (
from manim.utils.iterables import tuplify

EPSILON = 0.0001

[docs]class SampleSpace(Rectangle): """A mobject representing a twodimensional rectangular sampling space. Examples -------- .. manim:: ExampleSampleSpace :save_last_frame: class ExampleSampleSpace(Scene): def construct(self): poly1 = SampleSpace(stroke_width=15, fill_opacity=1) poly2 = SampleSpace(width=5, height=3, stroke_width=5, fill_opacity=0.5) poly3 = SampleSpace(width=2, height=2, stroke_width=5, fill_opacity=0.1) poly3.divide_vertically(p_list=np.array([0.37, 0.13, 0.5]), colors=[BLACK, WHITE, GRAY], vect=RIGHT) poly_group = VGroup(poly1, poly2, poly3).arrange() self.add(poly_group) """ def __init__( self, height=3, width=3, fill_color=DARK_GREY, fill_opacity=1, stroke_width=0.5, stroke_color=LIGHT_GREY, default_label_scale_val=1, ): super().__init__( height=height, width=width, fill_color=fill_color, fill_opacity=fill_opacity, stroke_width=stroke_width, stroke_color=stroke_color, ) self.default_label_scale_val = default_label_scale_val def add_title(self, title="Sample space", buff=MED_SMALL_BUFF): # TODO, should this really exist in SampleSpaceScene title_mob = Tex(title) if title_mob.width > self.width: title_mob.width = self.width title_mob.next_to(self, UP, buff=buff) self.title = title_mob self.add(title_mob) def add_label(self, label): self.label = label def complete_p_list(self, p_list): new_p_list = list(tuplify(p_list)) remainder = 1.0 - sum(new_p_list) if abs(remainder) > EPSILON: new_p_list.append(remainder) return new_p_list def get_division_along_dimension(self, p_list, dim, colors, vect): p_list = self.complete_p_list(p_list) colors = color_gradient(colors, len(p_list)) last_point = self.get_edge_center(-vect) parts = VGroup() for factor, color in zip(p_list, colors): part = SampleSpace() part.set_fill(color, 1) part.replace(self, stretch=True) part.stretch(factor, dim) part.move_to(last_point, -vect) last_point = part.get_edge_center(vect) parts.add(part) return parts def get_horizontal_division(self, p_list, colors=[GREEN_E, BLUE_E], vect=DOWN): return self.get_division_along_dimension(p_list, 1, colors, vect) def get_vertical_division(self, p_list, colors=[MAROON_B, YELLOW], vect=RIGHT): return self.get_division_along_dimension(p_list, 0, colors, vect) def divide_horizontally(self, *args, **kwargs): self.horizontal_parts = self.get_horizontal_division(*args, **kwargs) self.add(self.horizontal_parts) def divide_vertically(self, *args, **kwargs): self.vertical_parts = self.get_vertical_division(*args, **kwargs) self.add(self.vertical_parts) def get_subdivision_braces_and_labels( self, parts, labels, direction, buff=SMALL_BUFF, min_num_quads=1, ): label_mobs = VGroup() braces = VGroup() for label, part in zip(labels, parts): brace = Brace(part, direction, min_num_quads=min_num_quads, buff=buff) if isinstance(label, (Mobject, OpenGLMobject)): label_mob = label else: label_mob = MathTex(label) label_mob.scale(self.default_label_scale_val) label_mob.next_to(brace, direction, buff) braces.add(brace) label_mobs.add(label_mob) parts.braces = braces parts.labels = label_mobs parts.label_kwargs = { "labels": label_mobs.copy(), "direction": direction, "buff": buff, } return VGroup(parts.braces, parts.labels) def get_side_braces_and_labels(self, labels, direction=LEFT, **kwargs): assert hasattr(self, "horizontal_parts") parts = self.horizontal_parts return self.get_subdivision_braces_and_labels( parts, labels, direction, **kwargs ) def get_top_braces_and_labels(self, labels, **kwargs): assert hasattr(self, "vertical_parts") parts = self.vertical_parts return self.get_subdivision_braces_and_labels(parts, labels, UP, **kwargs) def get_bottom_braces_and_labels(self, labels, **kwargs): assert hasattr(self, "vertical_parts") parts = self.vertical_parts return self.get_subdivision_braces_and_labels(parts, labels, DOWN, **kwargs) def add_braces_and_labels(self): for attr in "horizontal_parts", "vertical_parts": if not hasattr(self, attr): continue parts = getattr(self, attr) for subattr in "braces", "labels": if hasattr(parts, subattr): self.add(getattr(parts, subattr)) def __getitem__(self, index): if hasattr(self, "horizontal_parts"): return self.horizontal_parts[index] elif hasattr(self, "vertical_parts"): return self.vertical_parts[index] return self.split()[index]
[docs]class BarChart(Axes): """Creates a bar chart. Inherits from :class:`~.Axes`, so it shares its methods and attributes. Each axis inherits from :class:`~.NumberLine`, so pass in ``x_axis_config``/``y_axis_config`` to control their attributes. Parameters ---------- values A sequence of values that determines the height of each bar. Accepts negative values. bar_names A sequence of names for each bar. Does not have to match the length of ``values``. y_range The y_axis range of values. If ``None``, the range will be calculated based on the min/max of ``values`` and the step will be calculated based on ``y_length``. x_length The length of the x-axis. If ``None``, it is automatically calculated based on the number of values and the width of the screen. y_length The length of the y-axis. bar_colors The color for the bars. Accepts a sequence of colors (can contain just one item). If the length of``bar_colors`` does not match that of ``values``, intermediate colors will be automatically determined. bar_width The length of a bar. Must be between 0 and 1. bar_fill_opacity The fill opacity of the bars. bar_stroke_width The stroke width of the bars. Examples -------- .. manim:: BarChartExample :save_last_frame: class BarChartExample(Scene): def construct(self): chart = BarChart( values=[-5, 40, -10, 20, -3], bar_names=["one", "two", "three", "four", "five"], y_range=[-20, 50, 10], y_length=6, x_length=10, x_axis_config={"font_size": 36}, ) c_bar_lbls = chart.get_bar_labels(font_size=48) self.add(chart, c_bar_lbls) """ def __init__( self, values: MutableSequence[float], bar_names: Sequence[str] | None = None, y_range: Sequence[float] | None = None, x_length: float | None = None, y_length: float | None = None, bar_colors: Iterable[str] = [ "#003f5c", "#58508d", "#bc5090", "#ff6361", "#ffa600", ], bar_width: float = 0.6, bar_fill_opacity: float = 0.7, bar_stroke_width: float = 3, **kwargs, ): if isinstance(bar_colors, str): logger.warning( "Passing a string to `bar_colors` has been deprecated since v0.15.2 and will be removed after v0.17.0, the parameter must be a list. " ) bar_colors = list(bar_colors) y_length = y_length if y_length is not None else config.frame_height - 4 self.values = values self.bar_names = bar_names self.bar_colors = bar_colors self.bar_width = bar_width self.bar_fill_opacity = bar_fill_opacity self.bar_stroke_width = bar_stroke_width x_range = [0, len(self.values), 1] if y_range is None: y_range = [ min(0, min(self.values)), max(0, max(self.values)), round(max(self.values) / y_length, 2), ] elif len(y_range) == 2: y_range = [*y_range, round(max(self.values) / y_length, 2)] if x_length is None: x_length = min(len(self.values), config.frame_width - 2) x_axis_config = {"font_size": 24, "label_constructor": Tex} self._update_default_configs( (x_axis_config,), (kwargs.pop("x_axis_config", None),) ) self.bars: VGroup = VGroup() self.x_labels: VGroup | None = None self.bar_labels: VGroup | None = None super().__init__( x_range=x_range, y_range=y_range, x_length=x_length, y_length=y_length, x_axis_config=x_axis_config, tips=kwargs.pop("tips", False), **kwargs, ) self._add_bars() if self.bar_names is not None: self._add_x_axis_labels() self.y_axis.add_numbers()
[docs] def _update_colors(self): """Initialize the colors of the bars of the chart. Sets the color of ``self.bars`` via ``self.bar_colors``. Primarily used when the bars are initialized with ``self._add_bars`` or updated via ``self.change_bar_values``. """ self.bars.set_color_by_gradient(*self.bar_colors)
[docs] def _add_x_axis_labels(self): """Essentially :meth`:~.NumberLine.add_labels`, but differs in that the direction of the label with respect to the x_axis changes to UP or DOWN depending on the value. UP for negative values and DOWN for positive values. """ val_range = np.arange( 0.5, len(self.bar_names), 1 ) # 0.5 shifted so that labels are centered, not on ticks labels = VGroup() for i, (value, bar_name) in enumerate(zip(val_range, self.bar_names)): # to accommodate negative bars, the label may need to be # below or above the x_axis depending on the value of the bar if self.values[i] < 0: direction = UP else: direction = DOWN bar_name_label = self.x_axis.label_constructor(bar_name) bar_name_label.font_size = self.x_axis.font_size bar_name_label.next_to( self.x_axis.number_to_point(value), direction=direction, buff=self.x_axis.line_to_number_buff, ) labels.add(bar_name_label) self.x_axis.labels = labels self.x_axis.add(labels)
[docs] def _create_bar(self, bar_number: int, value: float) -> Rectangle: """Creates a positioned bar on the chart. Parameters ---------- bar_number Determines the x-position of the bar. value The value that determines the height of the bar. Returns ------- Rectangle A positioned rectangle representing a bar on the chart. """ # bar measurements relative to the axis # distance from between the y-axis and the top of the bar bar_h = abs(self.c2p(0, value)[1] - self.c2p(0, 0)[1]) # width of the bar bar_w = self.c2p(self.bar_width, 0)[0] - self.c2p(0, 0)[0] bar = Rectangle( height=bar_h, width=bar_w, stroke_width=self.bar_stroke_width, fill_opacity=self.bar_fill_opacity, ) pos = UP if (value >= 0) else DOWN bar.next_to(self.c2p(bar_number + 0.5, 0), pos, buff=0) return bar
def _add_bars(self) -> None: for i, value in enumerate(self.values): tmp_bar = self._create_bar(bar_number=i, value=value) self.bars.add(tmp_bar) self._update_colors() self.add_to_back(self.bars)
[docs] def get_bar_labels( self, color: ParsableManimColor | None = None, font_size: float = 24, buff: float = MED_SMALL_BUFF, label_constructor: type[VMobject] = Tex, ): """Annotates each bar with its corresponding value. Use ``self.bar_labels`` to access the labels after creation. Parameters ---------- color The color of each label. By default ``None`` and is based on the parent's bar color. font_size The font size of each label. buff The distance from each label to its bar. By default 0.4. label_constructor The Mobject class to construct the labels, by default :class:`~.Tex`. Examples -------- .. manim:: GetBarLabelsExample :save_last_frame: class GetBarLabelsExample(Scene): def construct(self): chart = BarChart(values=[10, 9, 8, 7, 6, 5, 4, 3, 2, 1], y_range=[0, 10, 1]) c_bar_lbls = chart.get_bar_labels( color=WHITE, label_constructor=MathTex, font_size=36 ) self.add(chart, c_bar_lbls) """ bar_labels = VGroup() for bar, value in zip(self.bars, self.values): bar_lbl = label_constructor(str(value)) if color is None: bar_lbl.set_color(bar.get_fill_color()) else: bar_lbl.set_color(color) bar_lbl.font_size = font_size pos = UP if (value >= 0) else DOWN bar_lbl.next_to(bar, pos, buff=buff) bar_labels.add(bar_lbl) return bar_labels
[docs] def change_bar_values(self, values: Iterable[float], update_colors: bool = True): """Updates the height of the bars of the chart. Parameters ---------- values The values that will be used to update the height of the bars. Does not have to match the number of bars. update_colors Whether to re-initalize the colors of the bars based on ``self.bar_colors``. Examples -------- .. manim:: ChangeBarValuesExample :save_last_frame: class ChangeBarValuesExample(Scene): def construct(self): values=[-10, -8, -6, -4, -2, 0, 2, 4, 6, 8, 10] chart = BarChart( values, y_range=[-10, 10, 2], y_axis_config={"font_size": 24}, ) self.add(chart) chart.change_bar_values(list(reversed(values))) self.add(chart.get_bar_labels(font_size=24)) """ for i, (bar, value) in enumerate(zip(self.bars, values)): chart_val = self.values[i] if chart_val > 0: bar_lim = bar.get_bottom() aligned_edge = DOWN else: bar_lim = bar.get_top() aligned_edge = UP # check if the bar has height if chart_val != 0: quotient = value / chart_val if quotient < 0: aligned_edge = UP if chart_val > 0 else DOWN # if the bar is already positive, then we now want to move it # so that it is negative. So, we move the top edge of the bar # to the location of the previous bottom # if already negative, then we move the bottom edge of the bar # to the location of the previous top bar.stretch_to_fit_height(abs(quotient) * bar.height) else: # create a new bar since the current one has a height of zero (doesn't exist) temp_bar = self._create_bar(i, value) self.bars.remove(bar) self.bars.insert(i, temp_bar) bar.move_to(bar_lim, aligned_edge) if update_colors: self._update_colors() self.values[: len(values)] = values