Latest animations for diffyq part 3

Author: 3b1b

active_projects/ode/all_part3_scenes.py

@@ -39,6 +39,16 @@
     FlatEdgesForDiscreteEvolutionTinySteps,
     FlatEdgesContinuousEvolution,
     FlatAtBoundaryWords,
+    SlopeToHeatFlow,
+    CloserLookAtStraightLine,
+    WriteOutBoundaryCondition,
+    TeacherStudentsScene,
+    ManipulateSinExpSurface,
+    HeatEquationFrame,
+    ShowFreq1CosExpDecay,
+    ShowFreq2CosExpDecay,
+    ShowFreq4CosExpDecay,
+    CompareFreqDecays,
 
     # SimpleCosExpGraph,
     # AddMultipleSolutions,

active_projects/ode/part2/heat_equation.py

@@ -523,25 +523,24 @@ def update_arrows(arrows):
         self.arrows = arrows
 
     def initialize_updaters(self):
-        graph = self.graph
-        rod = self.rod
-        time_label = self.time_label
-
-        graph.add_updater(self.update_graph)
-        time_label.add_updater(
-            lambda d, dt: d.increment_value(dt)
-        )
-        rod.add_updater(self.color_rod_by_graph)
+        if hasattr(self, "graph"):
+            self.graph.add_updater(self.update_graph)
+        if hasattr(self, "rod"):
+            self.rod.add_updater(self.color_rod_by_graph)
+        if hasattr(self, "time_label"):
+            self.time_label.add_updater(
+                lambda d, dt: d.increment_value(dt)
+            )
 
     def let_play(self):
-        clock = self.clock
+        self.run_clock(self.wait_time)
 
-        # return
+    def run_clock(self, time):
         self.play(
             ClockPassesTime(
-                clock,
-                run_time=self.wait_time,
-                hours_passed=self.wait_time,
+                self.clock,
+                run_time=time,
+                hours_passed=time,
             ),
         )
 

active_projects/ode/part3/pi_creature_scenes.py

@@ -137,3 +137,39 @@ def construct(self):
         )
         self.wait(3)
 
+
+class SoWeGotNowhere(TeacherStudentsScene):
+    def construct(self):
+        self.student_says(
+            "So we've gotten\\\\nowhere!",
+            target_mode="angry",
+            added_anims=[
+                self.teacher.change, "guilty"
+            ]
+        )
+        self.change_all_student_modes("angry")
+        self.wait()
+        text = TexMobject(
+            "&\\text{Actually,}\\\\",
+            "&\\sin\\left({x}\\right)"
+            "e^{-\\alpha {t}}\\\\",
+            "&\\text{isn't far off.}",
+            tex_to_color_map={
+                "{x}": GREEN,
+                "{t}": YELLOW,
+            }
+        )
+        text.scale(0.8)
+        self.teacher_says(
+            text,
+            content_introduction_class=FadeIn,
+            bubble_kwargs={
+                "width": 4,
+                "height": 3.5,
+            }
+        )
+        self.change_all_student_modes(
+            "pondering",
+            look_at_arg=self.screen
+        )
+        self.wait(3)