Module tests.moog.physics.test_tether_physics
Tests for moog/physics/tether_physics.py.
To run this test, navigate to this directory and run
$ pytest test_tether_physics.py --capture=tee-sys
Note: The –capture=tee-sys routes print statements to stdout, which is useful for debugging.
Alternatively, to run this test and any others, navigate to any parent directory and simply run
$ pytest --capture=tee-sys
This will run all test_* files in children directories.
Expand source code
"""Tests for moog/physics/tether_physics.py.
To run this test, navigate to this directory and run
```bash
$ pytest test_tether_physics.py --capture=tee-sys
```
Note: The --capture=tee-sys routes print statements to stdout, which is useful
for debugging.
Alternatively, to run this test and any others, navigate to any parent directory
and simply run
```bash
$ pytest --capture=tee-sys
```
This will run all test_* files in children directories.
"""
import sys
sys.path.insert(0, '...') # Allow imports from moog codebase
import collections
import matplotlib
from matplotlib import pyplot as plt
import numpy as np
import pytest
from moog import physics as physics_lib
from moog import shapes
from moog import sprite
from moog.physics import collisions
from moog.observers import pil_renderer
# Absolute error tolerance for testing scalars (positions, velocities, etc.)
_ATOL = 0.001
class MatplotlibUI():
"""Matplotlib UI.
This can be used to visualize test conditions.
"""
def __init__(self, image_size=128, anti_aliasing=3):
"""Constructor."""
plt.ion()
self._fig, self._ax = plt.subplots()
self._ax.axis('off')
self._imshow = self._ax.imshow(
np.zeros((image_size, image_size, 3)), interpolation='none')
self._renderer = pil_renderer.PILRenderer(
image_size=(image_size, image_size), anti_aliasing=anti_aliasing)
self._ax.set_xticks([])
self._ax.set_yticks([])
plt.show(block=False)
plt.pause(0.1)
def _render(self, state):
"""Renderer a state (ordereddict of iterables of sprites)."""
self._imshow.set_data(self._renderer(state))
plt.draw()
plt.pause(0.1)
def _simulate_video(self, physics, state, steps):
"""Simulate and display video."""
physics.step(state)
for i, s in enumerate(state['sprites']):
print('')
print(f'Sprite {i}')
print(f'position: [{s.position[0]:.4f}, {s.position[1]:.4f}]')
print(f'velocity: [{s.velocity[0]:.4f}, {s.velocity[1]:.4f}]')
print(f'angle_vel: {s.angle_vel:.4f}')
for _ in range(steps - 1):
physics.step(state)
self._render(state)
# Print the true positions, velocities, and angular velocities of the
# sprites, rounded to 4 decimal places.
for i, s in enumerate(state['sprites']):
print('')
print(f'Sprite {i}')
print(f'position: [{s.position[0]:.4f}, {s.position[1]:.4f}]')
print(f'velocity: [{s.velocity[0]:.4f}, {s.velocity[1]:.4f}]')
print(f'angle_vel: {s.angle_vel:.4f}')
def get_state():
"""Get initial state."""
sprite_0 = sprite.Sprite(
x=0.5, y=0.7, scale=0.1, shape='triangle',
x_vel=0.04, y_vel=-0.02, c0=255, angle=2.)
sprite_1 = sprite.Sprite(
x=0.2, y=0.6, scale=0.1, shape='triangle',
x_vel=0., y_vel=0., c1=255, angle=1.)
sprite_2 = sprite.Sprite(
x=0.6, y=0.3, scale=0.1, shape='triangle',
x_vel=0., y_vel=0., c2=255)
sprites = [sprite_0, sprite_1, sprite_2]
walls = shapes.border_walls(
visible_thickness=0.05, c0=128, c1=128, c2=128)
state = collections.OrderedDict([('walls', walls), ('sprites', sprites)])
return state
class TestTether():
"""Test Tether."""
def _run_test(self, tether, step_1_state, final_state, plot=False):
"""Run test.
Set plot = True to display videos of the test conditions.
Args:
tether: Tether force.
step_1_state: Iterable of lists, one for each sprite. Each element
is a list of [position, velocity, angle_vel] for the sprite
after the first physics step.
final_state: Same as step_1_state, except for the final step.
plot: Bool. Whether to display video or run test.
"""
state = get_state()
collision = physics_lib.Collision(
elasticity=0., symmetric=False, update_angle_vel=True)
physics = physics_lib.Physics(
(collision, 'sprites', 'walls'),
corrective_physics=[tether],
updates_per_env_step=10,
)
steps = 45
if plot:
MatplotlibUI()._simulate_video(physics, state, steps=steps)
else:
physics.step(state)
for s, pred in zip(state['sprites'], step_1_state):
assert np.allclose(s.position, pred[0], atol=_ATOL)
assert np.allclose(s.velocity, pred[1], atol=_ATOL)
assert np.allclose(s.angle_vel, pred[2], atol=_ATOL)
for _ in range(steps - 1):
physics.step(state)
for s, pred in zip(state['sprites'], final_state):
assert np.allclose(s.position, pred[0], atol=_ATOL)
assert np.allclose(s.velocity, pred[1], atol=_ATOL)
assert np.allclose(s.angle_vel, pred[2], atol=_ATOL)
def testTetherNoAngleUpdate(self, plot=False):
"""Tether.
Set plot = True to display videos of the test conditions.
"""
tether = physics_lib.Tether('sprites', update_angle_vel=False)
step_1_state = [
[[0.5133, 0.6933], [0.0133, -0.0067], 0.],
[[0.2133, 0.5933], [0.0133, -0.0067], 0.],
[[0.6133, 0.2933], [0.0133, -0.0067], 0.],
]
final_state = [
[[0.7710, 0.4900], [-0.0005, 0.], 0.],
[[0.4710, 0.3900], [-0.0005, 0.], 0.],
[[0.8671, 0.0939], [-0.0005, 0.], 0.],
]
self._run_test(tether, step_1_state, final_state, plot=plot)
def testTetherAngleUpdate(self, plot=False):
"""Tether.
Set plot = True to display videos of the test conditions.
"""
tether = physics_lib.Tether('sprites', update_angle_vel=True)
step_1_state = [
[[0.5206, 0.6900], [0.0205, -0.0103], -0.0447],
[[0.2165, 0.6035], [0.0166, 0.0033], -0.0447],
[[0.6027, 0.2860], [0.0025, -0.0140], -0.0447],
]
final_state = [
[[0.8341, 0.3401], [-0.0028, -0.0046], -0.0229],
[[0.7139, 0.6271], [0.0037, -0.0018], -0.0229],
[[0.4545, 0.2062], [-0.0059, 0.0041], -0.0229],
]
self._run_test(tether, step_1_state, final_state, plot=plot)
def testTetherAnchor(self, plot=False):
"""Tether.
Set plot = True to display videos of the test conditions.
"""
tether = physics_lib.Tether('sprites', anchor=np.array([0.2, 0.2]))
step_1_state = [
[[0.5190, 0.6881], [0.0188, -0.0122], -0.0385],
[[0.2154, 0.5997], [0.0154, -0.0006], -0.0385],
[[0.6036, 0.2845], [0.0033, -0.0155], -0.0385],
]
final_state = [
[[0.6927, 0.5118], [0., 0.], 0.],
[[0.3798, 0.5573], [0., 0.], 0.],
[[0.6025, 0.1233], [0., 0.], 0.]
]
self._run_test(tether, step_1_state, final_state, plot=plot)Functions
def get_state()-
Get initial state.
Expand source code
def get_state(): """Get initial state.""" sprite_0 = sprite.Sprite( x=0.5, y=0.7, scale=0.1, shape='triangle', x_vel=0.04, y_vel=-0.02, c0=255, angle=2.) sprite_1 = sprite.Sprite( x=0.2, y=0.6, scale=0.1, shape='triangle', x_vel=0., y_vel=0., c1=255, angle=1.) sprite_2 = sprite.Sprite( x=0.6, y=0.3, scale=0.1, shape='triangle', x_vel=0., y_vel=0., c2=255) sprites = [sprite_0, sprite_1, sprite_2] walls = shapes.border_walls( visible_thickness=0.05, c0=128, c1=128, c2=128) state = collections.OrderedDict([('walls', walls), ('sprites', sprites)]) return state
Classes
class MatplotlibUI (image_size=128, anti_aliasing=3)-
Matplotlib UI.
This can be used to visualize test conditions.
Constructor.
Expand source code
class MatplotlibUI(): """Matplotlib UI. This can be used to visualize test conditions. """ def __init__(self, image_size=128, anti_aliasing=3): """Constructor.""" plt.ion() self._fig, self._ax = plt.subplots() self._ax.axis('off') self._imshow = self._ax.imshow( np.zeros((image_size, image_size, 3)), interpolation='none') self._renderer = pil_renderer.PILRenderer( image_size=(image_size, image_size), anti_aliasing=anti_aliasing) self._ax.set_xticks([]) self._ax.set_yticks([]) plt.show(block=False) plt.pause(0.1) def _render(self, state): """Renderer a state (ordereddict of iterables of sprites).""" self._imshow.set_data(self._renderer(state)) plt.draw() plt.pause(0.1) def _simulate_video(self, physics, state, steps): """Simulate and display video.""" physics.step(state) for i, s in enumerate(state['sprites']): print('') print(f'Sprite {i}') print(f'position: [{s.position[0]:.4f}, {s.position[1]:.4f}]') print(f'velocity: [{s.velocity[0]:.4f}, {s.velocity[1]:.4f}]') print(f'angle_vel: {s.angle_vel:.4f}') for _ in range(steps - 1): physics.step(state) self._render(state) # Print the true positions, velocities, and angular velocities of the # sprites, rounded to 4 decimal places. for i, s in enumerate(state['sprites']): print('') print(f'Sprite {i}') print(f'position: [{s.position[0]:.4f}, {s.position[1]:.4f}]') print(f'velocity: [{s.velocity[0]:.4f}, {s.velocity[1]:.4f}]') print(f'angle_vel: {s.angle_vel:.4f}') class TestTether-
Test Tether.
Expand source code
class TestTether(): """Test Tether.""" def _run_test(self, tether, step_1_state, final_state, plot=False): """Run test. Set plot = True to display videos of the test conditions. Args: tether: Tether force. step_1_state: Iterable of lists, one for each sprite. Each element is a list of [position, velocity, angle_vel] for the sprite after the first physics step. final_state: Same as step_1_state, except for the final step. plot: Bool. Whether to display video or run test. """ state = get_state() collision = physics_lib.Collision( elasticity=0., symmetric=False, update_angle_vel=True) physics = physics_lib.Physics( (collision, 'sprites', 'walls'), corrective_physics=[tether], updates_per_env_step=10, ) steps = 45 if plot: MatplotlibUI()._simulate_video(physics, state, steps=steps) else: physics.step(state) for s, pred in zip(state['sprites'], step_1_state): assert np.allclose(s.position, pred[0], atol=_ATOL) assert np.allclose(s.velocity, pred[1], atol=_ATOL) assert np.allclose(s.angle_vel, pred[2], atol=_ATOL) for _ in range(steps - 1): physics.step(state) for s, pred in zip(state['sprites'], final_state): assert np.allclose(s.position, pred[0], atol=_ATOL) assert np.allclose(s.velocity, pred[1], atol=_ATOL) assert np.allclose(s.angle_vel, pred[2], atol=_ATOL) def testTetherNoAngleUpdate(self, plot=False): """Tether. Set plot = True to display videos of the test conditions. """ tether = physics_lib.Tether('sprites', update_angle_vel=False) step_1_state = [ [[0.5133, 0.6933], [0.0133, -0.0067], 0.], [[0.2133, 0.5933], [0.0133, -0.0067], 0.], [[0.6133, 0.2933], [0.0133, -0.0067], 0.], ] final_state = [ [[0.7710, 0.4900], [-0.0005, 0.], 0.], [[0.4710, 0.3900], [-0.0005, 0.], 0.], [[0.8671, 0.0939], [-0.0005, 0.], 0.], ] self._run_test(tether, step_1_state, final_state, plot=plot) def testTetherAngleUpdate(self, plot=False): """Tether. Set plot = True to display videos of the test conditions. """ tether = physics_lib.Tether('sprites', update_angle_vel=True) step_1_state = [ [[0.5206, 0.6900], [0.0205, -0.0103], -0.0447], [[0.2165, 0.6035], [0.0166, 0.0033], -0.0447], [[0.6027, 0.2860], [0.0025, -0.0140], -0.0447], ] final_state = [ [[0.8341, 0.3401], [-0.0028, -0.0046], -0.0229], [[0.7139, 0.6271], [0.0037, -0.0018], -0.0229], [[0.4545, 0.2062], [-0.0059, 0.0041], -0.0229], ] self._run_test(tether, step_1_state, final_state, plot=plot) def testTetherAnchor(self, plot=False): """Tether. Set plot = True to display videos of the test conditions. """ tether = physics_lib.Tether('sprites', anchor=np.array([0.2, 0.2])) step_1_state = [ [[0.5190, 0.6881], [0.0188, -0.0122], -0.0385], [[0.2154, 0.5997], [0.0154, -0.0006], -0.0385], [[0.6036, 0.2845], [0.0033, -0.0155], -0.0385], ] final_state = [ [[0.6927, 0.5118], [0., 0.], 0.], [[0.3798, 0.5573], [0., 0.], 0.], [[0.6025, 0.1233], [0., 0.], 0.] ] self._run_test(tether, step_1_state, final_state, plot=plot)Methods
def testTetherAnchor(self, plot=False)-
Tether.
Set plot = True to display videos of the test conditions.
Expand source code
def testTetherAnchor(self, plot=False): """Tether. Set plot = True to display videos of the test conditions. """ tether = physics_lib.Tether('sprites', anchor=np.array([0.2, 0.2])) step_1_state = [ [[0.5190, 0.6881], [0.0188, -0.0122], -0.0385], [[0.2154, 0.5997], [0.0154, -0.0006], -0.0385], [[0.6036, 0.2845], [0.0033, -0.0155], -0.0385], ] final_state = [ [[0.6927, 0.5118], [0., 0.], 0.], [[0.3798, 0.5573], [0., 0.], 0.], [[0.6025, 0.1233], [0., 0.], 0.] ] self._run_test(tether, step_1_state, final_state, plot=plot) def testTetherAngleUpdate(self, plot=False)-
Tether.
Set plot = True to display videos of the test conditions.
Expand source code
def testTetherAngleUpdate(self, plot=False): """Tether. Set plot = True to display videos of the test conditions. """ tether = physics_lib.Tether('sprites', update_angle_vel=True) step_1_state = [ [[0.5206, 0.6900], [0.0205, -0.0103], -0.0447], [[0.2165, 0.6035], [0.0166, 0.0033], -0.0447], [[0.6027, 0.2860], [0.0025, -0.0140], -0.0447], ] final_state = [ [[0.8341, 0.3401], [-0.0028, -0.0046], -0.0229], [[0.7139, 0.6271], [0.0037, -0.0018], -0.0229], [[0.4545, 0.2062], [-0.0059, 0.0041], -0.0229], ] self._run_test(tether, step_1_state, final_state, plot=plot) def testTetherNoAngleUpdate(self, plot=False)-
Tether.
Set plot = True to display videos of the test conditions.
Expand source code
def testTetherNoAngleUpdate(self, plot=False): """Tether. Set plot = True to display videos of the test conditions. """ tether = physics_lib.Tether('sprites', update_angle_vel=False) step_1_state = [ [[0.5133, 0.6933], [0.0133, -0.0067], 0.], [[0.2133, 0.5933], [0.0133, -0.0067], 0.], [[0.6133, 0.2933], [0.0133, -0.0067], 0.], ] final_state = [ [[0.7710, 0.4900], [-0.0005, 0.], 0.], [[0.4710, 0.3900], [-0.0005, 0.], 0.], [[0.8671, 0.0939], [-0.0005, 0.], 0.], ] self._run_test(tether, step_1_state, final_state, plot=plot)