def test_ipow_banned():
x = Var([1, 2, 3])
with pytest.raises(TypeError):
x **= 3
def test_rdiv_vars():
x = Var([3, 3, 3])
y = 6 / x
y.backward()
assert np.all(y == Var([2, 2, 2]))
assert np.all(y.grad(x) == np.array([-2 / 3, -2 / 3, -2 / 3]))
def test_rdiv_var_fails_with_divide_by_zero():
with pytest.raises((ZeroDivisionError, FloatingPointError)):
1 / Var([0, 2, 3])
def test_mul_var_number():
x = Var([3, 2, 1])
y = x * 5
y.backward()
assert np.all(y == Var([15, 10, 5]))
assert np.all(y.grad(x) == np.array([5, 5, 5]))
def test_div_var_number():
x = Var([10, 10])
y = x / 5
y.backward()
assert np.all(y == Var([2, 2]))
assert np.all(y.grad(x) == np.array([0.2, .2]))
def test_cosh():
var1 = Var(0.)
var2 = ops.cosh(var1)
var2.backward()
assert var2.val == pytest.approx(1)
assert var2.grad(var1) == np.array([0])
def test_atanh():
var1 = Var(0.)
var2 = ops.arctanh(var1)
var2.backward()
assert var2.val == pytest.approx(0)
assert var2.grad(var1) == np.array([1])
def test_rsub_var():
x = Var([1, 2, 3])
y = 6 - x
x.forward()
assert np.all(y == Var([5, 4, 3]))
assert np.all(y.grad(x) == np.array([-1, -1, -1]))
def test_exp():
var1 = Var(0)
var2 = ops.exp(var1)
var2.backward()
assert var2.val == pytest.approx(1)
assert var2.grad(var1) == np.array([1])
def test_radd_var():
x = Var([1, 2, 3])
y = 6 + x
x.forward()
assert np.all(y == Var([7, 8, 9]))
assert np.all(y.grad(x) == np.array([1, 1, 1]))
def test_sub_var_number():
x = Var([1, 2, 3])
y = x - 5
x.forward()
assert np.all(y == Var([-4, -3, -2]))
assert np.all(y.grad(x) == np.array([1, 1, 1]))
def test_init_var():
var = Var([1, 2, 3])
assert np.all(var.val == [1, 2, 3])
def test_add_var_number():
x = Var([1, 2, 3])
y = x + 5
x.forward()
assert np.all(y == Var([6, 7, 8]))
assert np.all(y.grad(x) == np.array([1, 1, 1]))
def test_abs():
x = Var([1, 2, -3])
y = abs(x)
x.forward()
assert np.all(y == Var([1, 2, 3]))
assert np.all(y.grad(x) == np.array([1, 1, -1]))
def test_acos():
var1 = Var(0.)
var2 = ops.arccos(var1)
var2.backward()
assert var2.val == pytest.approx(1.570796, abs=1e-2)
assert var2.grad(var1) == np.array([-1])
def test_log():
var1 = Var(1.)
var2 = ops.log(var1)
var2.backward()
assert var2.val == pytest.approx(0)
assert var2.grad(var1) == np.array([1])
def test_sin():
var1 = Var(np.pi)
var2 = ops.sin(var1)
var2.backward()
assert var2.val == pytest.approx(0)
assert var2.grad(var1) == np.array([-1])
def test_logistic():
var1 = Var(0)
var2 = ops.logistic(var1)
var2.backward()
assert var2.val == pytest.approx(0.5)
assert var2.grad(var1) == var2.val * (1 - var2.val)
def test_acosh():
var1 = Var(2.)
var2 = ops.arccosh(var1)
var2.backward()
assert var2.val == np.arccosh(2.)
assert var2.grad(var1) == np.array([1 / np.sqrt(3)])
def test_sqrt():
var1 = Var(4)
var2 = ops.sqrt(var1)
var2.backward()
assert var2.val == pytest.approx(2)
assert var2.grad(var1) == .5 * 1 / var2.val
def test_invalid_arg_raises_error():
var = Var([1, 2, 3])
with pytest.raises(TypeError):
var.grad('invalid value')
def test_neg():
var1 = Var(1)
var2 = ops.neg(var1)
var2.backward()
assert var2.val == pytest.approx(-1)
assert var2.grad(var1) == -1
def test_rmul_vars():
x = Var([3, 3, 3])
y = 6 * x
y.backward()
assert np.all(y == Var([18, 18, 18]))
assert np.all(y.grad(x) == np.array([6, 6, 6]))
def test_cos():
var1 = Var(np.pi)
var2 = ops.cos(var1)
var2.backward()
assert var2.val == pytest.approx(-1)
assert np.array([var2.grad(var1)]) == pytest.approx([0])
def test_div_var_number_fails_with_divide_by_zero():
with pytest.raises((ZeroDivisionError, FloatingPointError)):
Var([1, 2, 3]) / 0.
def test_abs():
var1 = Var(-1)
var2 = ops.abs(var1)
var2.backward()
assert var2.val == 1.
assert var2.grad(var1) == -1
def test_neg():
x = Var([1, 2, 3])
y = -x
y.backward()
assert np.all(y == Var([-1, -2, -3]))
assert np.all(y.grad(x) == np.array([-1, -1, -1]))
def test_composite_logexp():
x = Var(5)
y = ops.log(ops.exp(x))
y.backward()
assert np.all(x.val == pytest.approx(y.val))
assert np.all(y.grad(x) == 1)
def test_div_var_non_number():
with pytest.raises(TypeError):
Var([1, 2, 3]) / 'string'
def test_idiv_banned():
x = Var([1, 2, 3])
with pytest.raises(TypeError):
x /= 3
