def test_truncate_equivalent_to_scale(x: Vector, max_length: float):
"""Vector.scale_to and truncate are equivalent when max_length <= x.length"""
assume(max_length <= x.length)
note(f"x.length = {x.length}")
if max_length > 0:
note(f"x.length = {x.length / max_length} * max_length")
scale: Union[Vector, Type[Exception]]
truncate: Union[Vector, Type[Exception]]
try:
truncate = x.truncate(max_length)
except Exception as e:
truncate = type(e)
try:
scale = x.scale_to(max_length)
except Exception as e:
event(f"Exception {type(e).__name__} thrown")
scale = type(e)
if isinstance(scale, Vector) and x.length == max_length:
# Permit some edge-case where truncation and scaling aren't equivalent
assert isinstance(truncate, Vector)
assert scale.isclose(truncate, abs_tol=0, rel_tol=1e-12)
else:
assert scale == truncate
def test_truncate_length(x: Vector, max_length: float):
assert x.truncate(max_length).length <= (1 + 1e-14) * max_length
def test_truncate_invariant(x: Vector, max_length: float):
assume(x.length <= max_length)
assert x.truncate(max_length) == x
