Vector Field

The defined vector field VMobject in vector_field.py

• Class VectorField(VGroup)
• Class StreamLines(VGroup)
• ShowPassingFlashWithThinningStrokeWidth(AnimationGroup)
• AnimatedStreamLines(VGroup)

Class VectorField(VGroup)

VectorField is used to generate a vector field of specifed function for given parameters.

Example

Code

# folder/file: tut/manim_mobject_vectorfield_001a.py

from manimlib.scene.scene import Scene
from manimlib.mobject.vector_field import VectorField
from manimlib.animation.creation import ShowCreation
from manimlib.utils.space_ops import rotate_vector

class manim_mobject_vectorfield_001a(Scene):
    def construct(self):
        self.play(ShowCreation(VectorField(lambda p: rotate_vector(p, 3.1416 / 4)).scale(0.35).move_to([3,2,0])),run_time=2)
        self.play(ShowCreation(VectorField(lambda p: rotate_vector(p, 0.04)).scale(0.35).move_to([-3,2,0])),run_time=2)
        self.play(ShowCreation(VectorField(lambda p: rotate_vector(p, 3.1416 / 4),x_min=-6,x_max=-0.5,y_min=-4,y_max=0)),run_time=2)
        self.play(ShowCreation(VectorField(lambda p: rotate_vector(p, 0.04),x_min=0.5,x_max=6,y_min=-4,y_max=0)),run_time=2)

Output

Class StreamLines(VGroup)

StreamLines is used to generate stream lines of specifed function for given parameters.

Example

Code

# folder/file: tut/manim_mobject_streamlines_001a.py

from manimlib.scene.scene import Scene
from manimlib.mobject.vector_field import StreamLines
from manimlib.animation.creation import ShowCreation
from manimlib.utils.space_ops import rotate_vector

class manim_mobject_streamlines_001a(Scene):
    def construct(self):
        self.play(ShowCreation(StreamLines(lambda p: rotate_vector(p, 3.1416 / 4)).scale(0.15).move_to([3,2,0])),run_time=2)
        self.play(ShowCreation(StreamLines(lambda p: rotate_vector(p, 0.04)).scale(0.15).move_to([-3,2,0])),run_time=2)
        self.play(ShowCreation(StreamLines(lambda p: rotate_vector(p, 3.1416 / 4),x_min=-6,x_max=-0.5,y_min=-4,y_max=0)),run_time=2)
        self.play(ShowCreation(StreamLines(lambda p: rotate_vector(p, 0.04),x_min=0.5,x_max=6,y_min=-4,y_max=0)),run_time=2)

Output

Class ShowPassingFlashWithThinningStrokeWidth(AnimationGroup)

ShowPassingFlashWithThinningStrokeWidth is used to generate a show passing flash with thinning stroke width of specified animation for given parameters.

Example

Code

# folder/file: tut/manim_mobject_showpassingflashwiththinningstrokewidth_001a.py

from manimlib.scene.scene import Scene
from manimlib.mobject.vector_field import ShowPassingFlashWithThinningStrokeWidth
from manimlib.mobject.vector_field import StreamLines
from manimlib.utils.space_ops import rotate_vector

class manim_mobject_showpassingflashwiththinningstrokewidth_001a(Scene):
    def construct(self):
        streamlines1=StreamLines(lambda p: rotate_vector(p, 3.1416 / 4),x_min=-1.5,x_max=1.5,y_min=-1,y_max=1).scale(0.15).move_to([3,2,0])
        self.add(streamlines1)
        self.play(ShowPassingFlashWithThinningStrokeWidth(streamlines1),run_time=2)
        streamlines2=StreamLines(lambda p: rotate_vector(p, 0),x_min=-1.5,x_max=1.5,y_min=-1,y_max=1).scale(0.15).move_to([-3,2,0])
        self.add(streamlines2)
        self.play(ShowPassingFlashWithThinningStrokeWidth(streamlines2),run_time=2)
        streamlines3=StreamLines(lambda p: rotate_vector(p, 3.1416 / 4),x_min=-6,x_max=-0.5,y_min=-4,y_max=0)
        self.add(streamlines3)
        self.play(ShowPassingFlashWithThinningStrokeWidth(streamlines3),run_time=2)
        streamlines4=StreamLines(lambda p: rotate_vector(p, 0.04),x_min=0.5,x_max=6,y_min=-4,y_max=0)
        self.add(streamlines4)
        self.play(ShowPassingFlashWithThinningStrokeWidth(streamlines4),run_time=2)

Output

Class AnimatedStreamLines(VGroup)

AnimatedStreamLines is used to generate an animated stream lines of specified function for given parameters.

Example

Code

# folder/file: tut/manim_mobject_animatedstreamlines_001a.py

from manimlib.scene.scene import Scene
from manimlib.mobject.vector_field import StreamLines
from manimlib.mobject.vector_field import AnimatedStreamLines
from manimlib.utils.space_ops import rotate_vector

class manim_mobject_animatedstreamlines_001a(Scene):
    def construct(self):
        self.add(AnimatedStreamLines(StreamLines(lambda p: rotate_vector(p, 3.1416 / 4)).scale(0.15).move_to([3,2,0])))
        self.wait(2)
        self.add(AnimatedStreamLines(StreamLines(lambda p: rotate_vector(p, 0.04)).scale(0.15).move_to([-3,2,0])))
        self.wait(2)
        self.add(AnimatedStreamLines(StreamLines(lambda p: rotate_vector(p, 3.1416 / 4),x_min=-6,x_max=-0.5,y_min=-4,y_max=0)))
        self.wait(2)
        self.add(AnimatedStreamLines(StreamLines(lambda p:  rotate_vector(p, 0.04),x_min=0.5,x_max=6,y_min=-4,y_max=0)))
        self.wait(2)

Output