def test_bisec():
def f(x):
if x < 5: return -1
elif x >= 6: return 1
else: return 0
r=bisec(f, 0, 10, 1)
print(r)
assert r==5
def test_result2():
f = lambda x: x
x = bisec(f, -2, 1)
assert abs(x) < 1e-4
def test_result4():
f = lambda x: -x**3 + 1
x = bisec(f, -2, 1.5)
assert abs(x) < 1e-4
def test_result3():
f = lambda x: x**3 - 1
x = bisec(f, -2, 1.5)
assert abs(x) < 1e-4
def test_result(tol):
f = lambda x: x
x = bisec(f, -1, 1, tol=tol)
assert abs(x) < tol
def test_a_equal_b_equal_root(tol):
f = lambda x: x**2 - 1
x = bisec(f, -1, -1, tol=tol)
assert abs(x) < tol
def test_a_equal_b(tol):
f = lambda x: x**2 - 1
with pytest.raises(ValueError):
x = bisec(f, -2, -2, tol=tol)
def test_discont(tol):
f = lambda x: -1 if x < 0 else 1
with pytest.raises(ValueError):
x = bisec(f, -2, 1.5, tol=tol)
def test_zero_right(tol):
f = lambda x: x**2
x = bisec(f, -1, 0, tol=tol)
assert abs(x) < tol
def test_zero_left(tol):
f = lambda x: x**2
x = bisec(f, 0, 1, tol=tol)
assert abs(x) < tol
def test_no_zero(tol):
f = lambda x: x**2 + 1
with pytest.raises(ValueError):
x = bisec(f, -2, 1.5, tol=tol)
def test_plus_minus(tol):
f = lambda x: -x**3 + 1
x = bisec(f, -2, 1.5, tol=tol)
assert abs(x) < tol
def test_zero_right():
f = lambda x: x**2
x = bisec(f, -1, 0)
assert abs(x) < 1e-4
def test_zero_left():
f = lambda x: x**2
x = bisec(f, 0, 1)
assert abs(x) < 1e-4
def test_plus_minus():
f = lambda x: -x**3 + 1
x = bisec(f, -2, 1.5)
assert abs(x) < 1e-4
def test_a_equal_b_equal_root():
f = lambda x: x**2 - 1
x = bisec(f, -1, -1)
assert abs(x) < 1e-4
