ClaudeandClaude Opus 5.5
f626cbcda2
Save -> load into a fresh Simulation must restore populations (bitwise), flags, body and step counts, and both copies must stay bitwise identical after 40 further steps. Jets remain non-checkpointable (documented). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
67 lines
2.2 KiB
Python
67 lines
2.2 KiB
Python
"""Checkpoint save -> load round trip for a scene with passive bodies. Requires GPU.
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A fresh Simulation restored from the checkpoint must hold the same populations,
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flags, body count and step count, and must stay bitwise identical to the original
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after both continue for the same number of steps. Checkpoints with Jets are
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refused (documented limitation) and are not covered here.
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"""
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import os
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import tempfile
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import unittest
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import numpy as np
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from ._cases import make_sim
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# Three separated cylinders (pinball-like); cut-link receivers stay in bulk fluid.
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CIRCLES = (((40, 32), 6), ((56, 22), 6), ((56, 42), 6))
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def scene():
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sim = make_sim()
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sim.initialize()
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for center, radius in CIRCLES:
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sim.add_body("circle", center=center, radius=radius)
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sim.sync_bodies()
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return sim
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class CheckpointBodiesGPU(unittest.TestCase):
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def test_round_trip_is_bitwise_and_continues_identically(self):
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sim = scene()
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sim.run(60)
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with tempfile.NamedTemporaryFile(suffix=".h5", delete=False) as f:
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path = f.name
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restored = None
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try:
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saved = sim.save_checkpoint(path)
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restored = make_sim()
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restored.initialize()
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restored.load_checkpoint(saved)
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self.assertEqual(restored.bodies.count, len(CIRCLES))
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self.assertEqual(restored.stepper.step_count, sim.stepper.step_count)
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np.testing.assert_array_equal(restored.get_flags(), sim.get_flags())
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a, b = sim.get_ddf(), restored.get_ddf()
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self.assertEqual(a.dtype, b.dtype)
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self.assertEqual(a.tobytes(), b.tobytes())
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sim.run(40)
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restored.run(40)
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self.assertEqual(restored.stepper.step_count, sim.stepper.step_count)
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a, b = sim.get_ddf(), restored.get_ddf()
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self.assertTrue(np.isfinite(a).all())
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self.assertEqual(a.tobytes(), b.tobytes())
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for i in range(len(CIRCLES)):
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self.assertTrue(np.all(np.isfinite(restored.read_force(i))))
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finally:
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if restored is not None:
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restored.close()
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os.unlink(path)
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sim.close()
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if __name__ == "__main__":
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unittest.main()
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