started histogram class

active_projects/eop/histograms.py

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+from helpers import *
+from mobject import Mobject
+from mobject.vectorized_mobject import *
+from animation.animation import Animation
+from animation.transform import *
+from animation.simple_animations import *
+from topics.geometry import *
+from scene import Scene
+from camera import *
+from topics.number_line import *
+from topics.three_dimensions import *
+from topics.light import *
+from topics.characters import *
+from topics.numerals import *
+
+
+
+class Histogram(VMobject):
+
+	CONFIG = {
+		"start_color" : YELLOW,
+		"end_color" : BLUE,
+		"x_scale" : 1.0,
+		"y_scale" : 1.0,
+	}
+
+	def __init__(self, x_values, y_values, **kwargs):
+
+		digest_config(self, kwargs)
+
+		# preliminaries
+		self.x_values = x_values
+		self.y_values = y_values
+
+		self.x_steps = x_values[1:] - x_values[:-1]
+		self.x_min = x_values[0] - self.x_steps[0] * 0.5
+		self.x_posts = (x_values[1:] + x_values[:-1]) * 0.5
+		self.x_max = x_values[-1] + self.x_steps[-1] * 0.5
+		self.x_posts = np.insert(self.x_posts,0,self.x_min)
+		self.x_posts = np.append(self.x_posts,self.x_max)
+
+		self.x_widths = self.x_posts[1:] - self.x_posts[:-1]
+
+		self.x_values_scaled = self.x_scale * x_values
+		self.x_steps_scaled = self.x_scale * self.x_steps
+		self.x_posts_scaled = self.x_scale * self.x_posts
+		self.x_min_scaled = self.x_scale * self.x_min
+		self.x_max_scaled = self.x_scale * self.x_max
+		self.x_widths_scaled = self.x_scale * self.x_widths
+
+		self.y_values_scaled = self.y_scale * self.y_values
+
+		VMobject.__init__(self, **kwargs)
+		
+	def generate_points(self):
+
+		previous_bar = ORIGIN
+
+		outline_points = []
+
+		for (i,x) in enumerate(self.x_values):
+
+			bar = Rectangle(
+				width = self.x_widths_scaled[i],
+				height = self.y_values_scaled[i],
+			)
+			t = float(x - self.x_values[0])/(self.x_values[-1] - self.x_values[0])
+			bar_color = interpolate_color(
+				self.start_color,
+				self.end_color,
+				t
+			)
+			bar.set_fill(color = bar_color, opacity = 1)
+			bar.set_stroke(width = 0)
+			bar.next_to(previous_bar,RIGHT,buff = 0)
+			if i != 0:
+				height_diff = previous_bar.get_height() - bar.get_height()
+				bar.shift(height_diff * 0.5 * DOWN)
+			
+			self.add(bar)
+
+			if i == 0:
+				# start with the lower left
+				outline_points.append(bar.get_anchors()[-2])
+
+			# upper two points of each bar
+			outline_points.append(bar.get_anchors()[0])
+			outline_points.append(bar.get_anchors()[1])
+
+			previous_bar = bar
+
+		# close the outline
+			# lower right
+		outline_points.append(bar.get_anchors()[2])
+			# lower left
+		outline_points.append(outline_points[0])
+
+		self.outline = Polygon(*outline_points)
+		self.outline.set_stroke(color = WHITE)
+		self.add(self.outline)
+
+
+
+class SampleScene(Scene):
+
+	def construct(self):
+
+		x_values = np.array([1,3,6,10,15])
+		y_values = np.array([15,10,6,3,1])
+
+		hist = Histogram(
+			x_values = x_values,
+			y_values = y_values,
+			x_scale = 0.2,
+			y_scale = 0.2,
+		)
+		self.add(hist)
+		self.wait()
+
+
+
+
+
+
+
+
+
+
+
+
+