def test_success():
f.calls = 0
result = rootfinding.bracket_root(f, (0, -0.1))
check_result(result, f, f_calls=f.calls, has_bracket=True, has_root=False)
assert result.iterations >= 1
rootfinding.bisect(f, result.bracket, f_bracket=result.f_bracket)
def test_notabracket():
interval = (-1.00001, -2)
f.calls = 0
with pytest.raises(rootfinding.NotABracketError) as exc_info:
rootfinding.bisect(f, interval, maxiter=0)
exc = exc_info.value
check_notabracketerror(exc, f, interval, f_calls=f.calls)
def test_iterationlimit():
f.calls = 0
with pytest.raises(rootfinding.IterationLimitReached) as exc_info:
result = rootfinding.bracket_root(f, (-1, -2))
exc = exc_info.value
check_iterationlimitreached(exc, f, f_calls=f.calls)
with pytest.raises(rootfinding.NotABracketError):
rootfinding.bisect(f, exc.interval, f_bracket=exc.f_interval)
def test_instantbracket():
interval = (0, 2)
f_interval = (None, f(interval[1]))
f.calls = 0
result = rootfinding.bracket_root(f,
interval,
f_interval=f_interval,
maxiter=0)
assert f.calls == 1
check_result(result, f, f_calls=f.calls, has_bracket=True, has_root=False)
rootfinding.bisect(f, result.bracket, f_bracket=result.f_bracket)
def test_instant2():
bracket = (1, -1.00001)
f_bracket = (f(bracket[0]), None)
f.calls = 0
result = rootfinding.bisect(f, bracket, f_bracket=f_bracket, maxiter=0)
assert f.calls == 1
check_result(result, f, f_calls=f.calls, has_bracket=True, has_root=True)
assert result.root == 1
def test_instantrootwithbracket():
interval = (0, -1.00001)
f_interval = (f(interval[0]), None)
ftol = 1e-3
f.calls = 0
result = rootfinding.bracket_root(f,
interval,
f_interval=f_interval,
ftol=ftol,
maxiter=0)
assert f.calls == 1
check_result(result,
f,
ftol=ftol,
f_calls=f.calls,
has_bracket=True,
has_root=True)
rootfinding.bisect(f, result.bracket)
def test_iterationlimit():
bracket = (0.1, -1.5)
f.calls = 0
with pytest.raises(rootfinding.IterationLimitReached) as exc_info:
result = rootfinding.bisect(f, bracket, maxiter=1)
exc = exc_info.value
assert f.calls == 3
check_iterationlimitreached(exc, f, f_calls=f.calls)
assert any(a == b for a, b in zip(bracket, exc.interval))
def test_success():
ftol = 4 * sys.float_info.epsilon
f.calls = 0
result = rootfinding.bisect(f, (0.1, -1.5), ftol=ftol)
check_result(result,
f,
ftol=ftol,
f_calls=f.calls,
has_bracket=True,
has_root=True)
assert result.root == pytest.approx(-1)
def test_invalidmaxiter():
with pytest.raises(ValueError):
rootfinding.bisect(f, (0, -0.1), maxiter=-0.5)
def test_invalidftol():
with pytest.raises(ValueError):
rootfinding.bisect(f, (0, -0.1), ftol=-1e-3)