def test_Tensor_repr():
x, y, z = symbols("x y z")
test_list = [[[x, y], [y, sin(2 * z) - 2 * sin(z) * cos(z)]],
[[z**2, x], [y, z]]]
obj1 = Tensor(test_list, config="ull")
machine_representation = repr(obj1)
assert not "object at 0x" in machine_representation
def test_Tensor():
x, y, z = symbols("x y z")
test_list = [[[x, y], [y, sin(2 * z) - 2 * sin(z) * cos(z)]], [[z ** 2, x], [y, z]]]
test_arr = Array(test_list)
obj1 = Tensor(test_arr)
obj2 = Tensor(test_list)
assert obj1.tensor() == obj2.tensor()
assert isinstance(obj1.tensor(), Array)
assert obj1.simplify()[0, 1, 1] == 0
def test_Tensor_getitem():
x, y, z = symbols("x y z")
test_list = [[[x, y], [y, sin(2 * z) - 2 * sin(z) * cos(z)]], [[z ** 2, x], [y, z]]]
obj = Tensor(test_list)
n = 2
for i in range(n ** 3):
p, q, r = i % n, int(i / n) % n, int(i / n ** 2) % n
assert obj[p, q, r] - test_list[p][q][r] == 0
def test_TypeError3():
scht = schwarzschild_tensor().tensor()
# pass string containing elements other than 'l' or 'u'
try:
obj = Tensor(scht, config="al")
assert False
except TypeError:
assert True
def test_TypeError2():
scht = schwarzschild_tensor().tensor()
# pass non str object
try:
obj = Tensor(scht, config=0)
assert False
except TypeError:
assert True
def test_Tensor():
x, y, z = symbols("x y z")
test_list = [[[x, y], [y, sin(2 * z) - 2 * sin(z) * cos(z)]],
[[z**2, x], [y, z]]]
test_arr = Array(test_list)
obj1 = Tensor(test_arr, config="ull")
obj2 = Tensor(test_list, config="ull")
assert obj1.tensor() == obj2.tensor()
assert isinstance(obj1.tensor(), Array)
def test_Tensor_simplify():
x, y, z = symbols("x y z")
test_list = [[[x, y], [y, sin(2 * z) - 2 * sin(z) * cos(z)]], [[z ** 2, x], [y, z]]]
obj = Tensor(test_list)
# with set_self = False
assert obj.simplify(set_self=False)[0, 1, 1] == 0
assert not obj.tensor()[0, 1, 1] == 0
# with set_self = True
obj.simplify(set_self=True)
assert obj.tensor()[0, 1, 1] == 0
def schwarzschild_tensor():
symbolstr = "t r theta phi"
syms = symbols(symbolstr)
G, M, c, a = symbols("G M c a")
# using metric values of schwarschild space-time
# a is schwarzschild radius
list2d = np.zeros((4, 4), dtype=int).tolist()
list2d[0][0] = 1 - (a / syms[1])
list2d[1][1] = -1 / ((1 - (a / syms[1])) * (c ** 2))
list2d[2][2] = -1 * (syms[1] ** 2) / (c ** 2)
list2d[3][3] = -1 * (syms[1] ** 2) * (sin(syms[2]) ** 2) / (c ** 2)
sch = Tensor(list2d)
return sch
def test_tensor_scalar(scalar):
scalar_tensor = Tensor(scalar)
assert scalar_tensor.tensor().rank() == 0
def test_TypeError3():
scht = schwarzschild_tensor().tensor()
# pass string containing elements other than 'l' or 'u'
obj = Tensor(scht, config="al")
def test_TypeError2():
scht = schwarzschild_tensor().tensor()
# pass non str object
obj = Tensor(scht, config=0)
def test_Tensor_str():
x, y, z = symbols("x y z")
test_list = [[[x, y], [y, x]], [[z, x], [y, z]]]
obj1 = Tensor(test_list)
assert "object at 0x" not in str(obj1)
def test_ValueError1():
x, y = symbols("x y")
test_list = [[x, y], [y, x]]
# pass array with shape (2,2) when (2,2,2) implied by argument syms
obj = Tensor(test_list, config="lll")
def test_TypeError1():
# pass non array, number or expression in arr
obj = Tensor("value", config="ll")
def test_Tensor_str():
x, y, z = symbols("x y z")
test_list = [[[x, y], [y, x]], [[z, x], [y, z]]]
obj1 = Tensor(test_list, config="ull", name="Test")
assert "object at 0x" not in str(obj1)
assert "Test" in str(obj1)