Finished with preliminary chapter 2 animations

animation/transform.py

@@ -92,14 +92,19 @@ class ApplyMethod(Transform):
             **kwargs
         )
 
-class FadeOut(ApplyMethod):
+class FadeOut(Transform):
     CONFIG = {
         "remover" : True, 
     }
     def __init__(self, mobject, **kwargs):
-        ApplyMethod.__init__(self, mobject.fade, 1, **kwargs)
+        target = mobject.copy()
+        target.fade(1)
+        if isinstance(mobject, VMobject):
+            target.set_stroke(width = 0)
+            target.set_fill(opacity = 0)
+        Transform.__init__(self, mobject, target, **kwargs)
 
-    def cleanup(self):
+    def clean_up(self):
         self.update(0)
 
 class FadeIn(Transform):

eola/chapter1.py

@@ -25,6 +25,12 @@ from eola.chapter0 import UpcomingSeriesOfVidoes
 import random
 
 
+def plane_wave_homotopy(x, y, z, t):
+    norm = np.linalg.norm([x, y])
+    tau = interpolate(5, -5, t) + norm/SPACE_WIDTH
+    alpha = sigmoid(tau)
+    return [x, y + 0.5*np.sin(2*np.pi*alpha), z]
+
 class Physicist(PiCreature):
     CONFIG = {
         "color" : PINK,
@@ -319,7 +325,7 @@ class DifferentConceptions(Scene):
             v_array, TexMobject("+"), w_array, TexMobject("="), sum_array
         )
         arrays.arrange_submobjects(RIGHT)
-        arrays.scale(0.5)
+        arrays.scale(0.75)
         arrays.to_edge(RIGHT).shift(UP)
 
         v_sym = TexMobject("\\vec{\\textbf{v}}")
@@ -331,8 +337,7 @@ class DifferentConceptions(Scene):
         statement = TextMobject("We'll ignore him \\\\ for now")
         statement.highlight(PINK)
         statement.scale_to_fit_width(arrays.get_width())
-        statement.next_to(arrays, DOWN, buff = 2)
+        statement.next_to(arrays, DOWN, buff = 1.5)
-        arrow_to_mathy = Arrow(statement, mathy, color = PINK, buff = 0)
         circle = Circle()
         circle.shift(syms.get_bottom())
 
@@ -349,7 +354,6 @@ class DifferentConceptions(Scene):
         self.play(Blink(mathy))
         self.add_scaling(arrows, syms, arrays)
         self.play(Write(statement))
-        self.play(ShowCreation(arrow_to_mathy, submobject_mode = "one_at_a_time"))
         self.play(ApplyMethod(mathy.change_mode, "sad"))
         self.dither()
         self.play(
@@ -375,7 +379,7 @@ class DifferentConceptions(Scene):
             matrix_to_mobject(["2(3)", "2(-5)"])
         )
         s_arrays.arrange_submobjects(RIGHT)
-        s_arrays.scale(0.5)
+        s_arrays.scale(0.75)
         s_arrays.next_to(arrays, DOWN)
 
         s_syms = TexMobject(["2", "\\vec{\\textbf{v}}"])
@@ -797,7 +801,7 @@ class VectorAdditionNumerically(VectorScene):
         x_axis, y_axis = axes.split()
 
         v1 = self.add_vector([1, 2])
-        coords1, x_line1, y_line1 = self.vector_to_coords(v1, cleanup = False)
+        coords1, x_line1, y_line1 = self.vector_to_coords(v1, clean_up = False)
         self.play(ApplyFunction(
             lambda m : m.next_to(y_axis, RIGHT).to_edge(UP),
             coords1
@@ -805,7 +809,7 @@ class VectorAdditionNumerically(VectorScene):
         plus.next_to(coords1, RIGHT)
 
         v2 = self.add_vector([3, -1], color = MAROON_B)
-        coords2, x_line2, y_line2 = self.vector_to_coords(v2, cleanup = False)
+        coords2, x_line2, y_line2 = self.vector_to_coords(v2, clean_up = False)
         self.dither()
         self.play(
             ApplyMethod(coords2.next_to, plus, RIGHT),
@@ -1020,7 +1024,7 @@ class ScalingNumerically(VectorScene):
         equals = TexMobject("=")
         self.add_axes()
         v = self.add_vector([3, 1])
-        v_coords, vx_line, vy_line = self.vector_to_coords(v, cleanup = False)
+        v_coords, vx_line, vy_line = self.vector_to_coords(v, clean_up = False)
         self.play(ApplyMethod(v_coords.to_edge, UP))
         two_dot.next_to(v_coords, LEFT)
         equals.next_to(v_coords, RIGHT)
@@ -1031,7 +1035,7 @@ class ScalingNumerically(VectorScene):
             Write(two_dot, run_time = 1)
         )
         two_v_coords, two_v_x_line, two_v_y_line = self.vector_to_coords(
-            two_v, cleanup = False
+            two_v, clean_up = False
         )
         self.play(
             ApplyMethod(two_v_coords.next_to, equals, RIGHT),
@@ -1233,12 +1237,6 @@ class ManipulateSpace(LinearTransformationScene):
         pi_creature.shift(-pi_creature.get_corner(DOWN+LEFT))
         self.plane.prepare_for_nonlinear_transform()
 
-        def homotopy(x, y, z, t):
-            norm = np.linalg.norm([x, y])
-            tau = interpolate(5, -5, t) + norm/SPACE_WIDTH
-            alpha = sigmoid(tau)
-            return [x, y + 0.5*np.sin(2*np.pi*alpha), z]
-
         self.play(ShowCreation(
             self.plane, 
             submobject_mode = "one_at_a_time",
@@ -1247,7 +1245,7 @@ class ManipulateSpace(LinearTransformationScene):
         self.play(FadeIn(pi_creature))
         self.play(Blink(pi_creature))
         self.plane.add(pi_creature)
-        self.play(Homotopy(homotopy, self.plane, run_time = 3))
+        self.play(Homotopy(plane_wave_homotopy, self.plane, run_time = 3))
         self.dither(2)
         self.apply_matrix([[2, 1], [1, 2]])
         self.dither()

eola/two_d_space.py

@@ -127,6 +127,15 @@ class VectorScene(Scene):
         self.add(axes)
         return axes
 
+    def lock_in_dim_grid(self, dimness = 0.7, axes_dimness = 0.5):
+        plane = self.add_plane()
+        axes = plane.get_axes()
+        plane.fade(dimness)
+        axes.highlight(WHITE)
+        axes.fade(axes_dimness)
+        self.add(axes)
+        self.freeze_background()
+
     def add_vector(self, vector, animate = True, color = YELLOW):
         if not isinstance(vector, Arrow):
             vector = Vector(vector, color = color)
@@ -202,7 +211,7 @@ class VectorScene(Scene):
         y_coord.highlight(Y_COLOR)
         return y_coord
 
-    def coords_to_vector(self, vector, coords_start = 2*RIGHT+2*UP, cleanup = True):
+    def coords_to_vector(self, vector, coords_start = 2*RIGHT+2*UP, clean_up = True):
         starting_mobjects = list(self.mobjects)
         array = Matrix(vector)
         array.shift(coords_start)
@@ -231,11 +240,11 @@ class VectorScene(Scene):
         self.play(ShowCreation(y_line))
         self.play(ShowCreation(arrow))
         self.dither()
-        if cleanup:
+        if clean_up:
             self.clear()
             self.add(*starting_mobjects)
 
-    def vector_to_coords(self, vector, integer_labels = True, cleanup = True):
+    def vector_to_coords(self, vector, integer_labels = True, clean_up = True):
         starting_mobjects = list(self.mobjects)
         show_creation = False
         if isinstance(vector, Arrow):
@@ -281,7 +290,7 @@ class VectorScene(Scene):
 
         self.remove(x_coord_start, y_coord_start, brackets)
         self.add(array)
-        if cleanup:
+        if clean_up:
             self.clear()
             self.add(*starting_mobjects)
         return array, x_line, y_line

mobject/tex_mobject.py

@@ -31,8 +31,7 @@ class TexMobject(SVGMobject):
         "fill_opacity"      : 1.0,
         "fill_color"        : WHITE,
         "should_center"     : True,
-        "next_to_direction" : RIGHT,
+        "separate_list_arg_with_spaces" : True,
-        "next_to_buff"      : 0.25,
         "initial_scale_val" : TEX_MOB_SCALE_VAL,
         "organize_left_to_right" : False,
         "propogate_style_to_family" : True,
@@ -51,30 +50,28 @@ class TexMobject(SVGMobject):
 
 
     def generate_points(self):
-        if isinstance(self.expression, list):
+        is_list = isinstance(self.expression, list)
-            self.handle_list_expression()
+        separator = ""
-        else:
+        if is_list and self.separate_list_arg_with_spaces:
-            self.svg_file = tex_to_svg_file(
+            separator = " "
-                "".join(self.expression),
+        expression = separator.join(self.expression)
-                self.template_tex_file
+        self.svg_file = tex_to_svg_file(expression, self.template_tex_file)
-            )
         SVGMobject.generate_points(self)
+        if is_list:
+            self.handle_list_expression(self.expression)
 
 
-    def handle_list_expression(self):
+    def handle_list_expression(self, list_expression):
-        #TODO, next_to not sufficient?
+        new_submobjects = []
-        subs = [
+        curr_index = 0
-            TexMobject(expr)
+        for expr in list_expression:
-            for expr in self.expression
+            model = TexMobject(expr, **self.CONFIG)
-        ]
+            new_index = curr_index + len(model.submobjects)
-        self.initial_scale_val = 1
+            new_submobjects.append(VMobject(
-        for sm1, sm2 in zip(subs, subs[1:]):
+                *self.submobjects[curr_index:new_index]
-            sm2.next_to(
+            ))
-                sm1,
+            curr_index = new_index
-                self.next_to_direction, 
+        self.submobjects = new_submobjects
-                buff = self.next_to_buff
-            )
-        self.submobjects = subs
         return self
 
     def organize_submobjects_left_to_right(self):

mobject/vectorized_mobject.py

@@ -93,8 +93,7 @@ class VMobject(Mobject):
 
     def get_stroke_color(self):
         try:
-            self.stroke_rgb[self.stroke_rgb<0] = 0
+            self.stroke_rgb = np.clip(self.stroke_rgb, 0, 1)
-            self.stroke_rgb[self.stroke_rgb>1] = 1
             return Color(rgb = self.stroke_rgb)
         except:
             return Color(WHITE)

scene/scene.py

@@ -104,7 +104,12 @@ class Scene(object):
         mobjects = list(it.chain(*[m.submobject_family() for m in mobjects]))
         if len(mobjects) == 0:
             return
-        self.mobjects = filter(lambda m : m not in mobjects, self.mobjects)
+        self.mobjects = filter(
+            lambda m : not set(
+                m.family_members_with_points()
+            ).issubset(mobjects),
+            self.mobjects
+        )
         return self
 
     def bring_to_front(self, mobject):

topics/numerals.py

@@ -1,12 +1,13 @@
 
 
+from mobject.vectorized_mobject import VMobject
 from mobject.tex_mobject import TexMobject
 from animation import Animation
 from helpers import *
 
 
 
-class DecimalNumber(TexMobject):
+class DecimalNumber(VMobject):
     CONFIG = {
         "num_decimal_points" : 2,
         "digit_to_digit_buff" : 0.05
@@ -14,7 +15,10 @@ class DecimalNumber(TexMobject):
     def __init__(self, float_num, **kwargs):
         digest_config(self, kwargs)
         num_string = '%.*f' % (self.num_decimal_points, float_num)
-        TexMobject.__init__(self, list(num_string))
+        VMobject.__init__(self, *[
+            TexMobject(char)
+            for char in num_string
+        ], **kwargs)
         self.arrange_submobjects(
             buff = self.digit_to_digit_buff,
             aligned_edge = DOWN