1 files changed, 76 insertions, 0 deletions
diff --git a/FSF-2020/calculus-of-several-variables/div-curl-grad-and-all-that/Curl and Div/DivCurl_file1_sources-and-sinks.py b/FSF-2020/calculus-of-several-variables/div-curl-grad-and-all-that/Curl and Div/DivCurl_file1_sources-and-sinks.py
new file mode 100644
index 0000000..d26525e
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/div-curl-grad-and-all-that/Curl and Div/DivCurl_file1_sources-and-sinks.py
@@ -0,0 +1,76 @@
+from manimlib.imports import *
+import numpy as np
+
+def divergence(coordinate):
+	x,y = coordinate[:2]
+	return np.array([
+			np.sin(x),
+			np.cos(y),
+			0
+		])
+
+def curl(coordinate):
+    x,y = coordinate[:2]
+    return np.array([
+            np.sin(y),
+            np.cos(x),
+            0
+        ])
+
+class fluid_flow(Scene):
+	def construct(self):
+
+
+
+		ball_a = Dot().set_color_by_gradient(["#F87666", "#F53A23", PURPLE_E]).move_to(np.array([-6,-1,0])).fade(0.2).scale(1.2)
+		ball_b = Dot().set_color_by_gradient(["#F87666", "#F53A23", PURPLE_E]).move_to(np.array([0.1,3,0])).fade(0.2).scale(1.2)
+		ball_c = Dot().set_color_by_gradient(["#F87666", "#F53A23", PURPLE_E]).move_to(np.array([-0.5,-1, 0])).fade(0.2).scale(1.2)
+		ball_d = Dot().set_color_by_gradient(["#F87666", "#F53A23", PURPLE_E]).move_to(np.array([4.5,-1.2,0])).fade(0.2).scale(1.2)
+		ball2 = Dot().set_color_by_gradient(["#F87666", "#F53A23", PURPLE_E]).move_to(np.array([-0.5,0,0])).fade(0.2).scale(1.2)
+		ball3 = Dot().set_color_by_gradient(["#F87666", "#F53A23", PURPLE_E]).move_to(np.array([-1.5,1.2,0])).fade(0.2).scale(1.2)
+		ball4 = Dot().set_color_by_gradient(["#F87666", "#F53A23", PURPLE_E]).move_to(np.array([-1.5,-1.2,0])).fade(0.2).scale(1.2)
+		ball5 = Sphere(radius = 0.2, chekerboard_colors =["#F87666", "#F53A23", PURPLE_E]).set_color_by_gradient(["#F87666", "#F53A23", PURPLE_E]).fade(0.2).move_to(np.array([-4.7,0,0]))
+
+		flow_one = StreamLines(
+			divergence,
+			virtual_time=3,
+			min_magnitude=0,
+			max_magnitude=1,
+		).set_color_by_gradient(["#003853", "#0478A1","#04AED9", WHITE])
+		flow_div =(AnimatedStreamLines(
+			flow_one,
+			line_anim_class=ShowPassingFlashWithThinningStrokeWidth
+		))
+
+		flow_two = StreamLines(
+			curl,
+			
+			virtual_time=3,
+			min_magnitude=0,
+			max_magnitude=1,
+		).set_color_by_gradient(["#003853", "#0478A1","#04AED9", WHITE])
+		flow_curl =(AnimatedStreamLines(
+			flow_two,
+			line_anim_class=ShowPassingFlashWithThinningStrokeWidth
+		))
+
+		label_div = TexMobject(r"\textit{Fluid flows out from }", r"\textit{sources }", r"\textit{and into }", r"\textit{sinks}" ).move_to(np.array([0,3.5, 0])).set_stroke(width = 1.5).scale(0.7)
+		label_div[1].set_color("#F87666")
+		label_div[3].set_color("#F87666")
+		title_div = TexMobject(r"Divergence").set_stroke(width = 1.5).move_to(3*DOWN).set_color("#F87666").scale(1.2)
+		label_curl = TexMobject(r"\textit{Fluid also rotates }", r"\textit{clockwise }", r"\textit{and }", r"\textit{counter-clockwise}" ).move_to(np.array([0,3.5, 0])).set_stroke(width = 1.5).scale(0.7)
+		label_curl[1].set_color("#F87666")
+		label_curl[3].set_color("#F87666")
+		title_curl = TexMobject(r"Curl").set_stroke(width = 1.5).move_to(3*DOWN).set_color("#F87666").scale(1.2)
+
+
+
+
+		self.add(flow_div, label_div)
+		self.play(Write(title_div))
+		self.wait(5)
+		self.remove(flow_div)
+		self.wait()
+		self.add(flow_curl)
+		self.play(ReplacementTransform(label_div, label_curl), ReplacementTransform(title_div, title_curl))
+		self.wait(6)