def testGraphModeEagerGradError(self):
with context.graph_mode():
def f():
x = variable_scope.get_variable(
'v', initializer=constant_op.constant(1.0))
return x * constant_op.constant(2.0)
with self.assertRaisesRegexp(ValueError,
'No trainable variables were accessed'):
backprop.implicit_val_and_grad(f)()
def testCustomGradient(self):
@custom_gradient.custom_gradient
def my_mul(x, y):
result = x * y
def grad(dr):
return [dr * y, dr * x]
return result, grad
lr = 0.25
x = resource_variable_ops.ResourceVariable(2., name='x')
def loss(x):
return my_mul(2., x.read_value())
loss_grads_fn = backprop.implicit_val_and_grad(loss)
losses = []
for _ in range(5):
loss, grads_and_vars = loss_grads_fn(x)
losses.append(loss.numpy())
for (grad, var) in grads_and_vars:
var.assign_sub(lr * grad)
self.assertAllEqual(losses, [4.0, 3., 2., 1., 0.])
def testCustomGradient(self):
@custom_gradient.custom_gradient
def my_mul(x, y):
result = x*y
def grad(dr):
return [dr*y, dr*x]
return result, grad
lr = 0.25
x = resource_variable_ops.ResourceVariable(2., name='x')
def loss(x):
return my_mul(2., x.read_value())
loss_grads_fn = backprop.implicit_val_and_grad(loss)
losses = []
for _ in range(5):
loss, grads_and_vars = loss_grads_fn(x)
losses.append(loss.numpy())
for (grad, var) in grads_and_vars:
var.assign_sub(lr*grad)
self.assertAllEqual(losses, [4.0, 3., 2., 1., 0.])
def testDifferentiatingFunctionThatReturnsNone(self):
def fn(x, y):
result = x*y # pylint: disable=unused-variable
x = constant_op.constant(1)
y = constant_op.constant(2)
loss_grads_fn = backprop.implicit_val_and_grad(fn)
with self.assertRaisesRegexp(
ValueError, 'Cannot differentiate a function that returns None; '
'did you forget to return a value from fn?'):
loss_grads_fn(x, y)
val_and_grads_fn = backprop.val_and_grad_function(fn)
with self.assertRaisesRegexp(
ValueError, 'Cannot differentiate a function that returns None; '
'did you forget to return a value from fn?'):
val_and_grads_fn(x, y)
def testDifferentiatingFunctionThatReturnsNone(self):
def fn(x, y):
result = x*y # pylint: disable=unused-variable
x = constant_op.constant(1)
y = constant_op.constant(2)
loss_grads_fn = backprop.implicit_val_and_grad(fn)
with self.assertRaisesRegexp(
ValueError, 'Cannot differentiate a function that returns None; '
'did you forget to return a value from fn?'):
loss_grads_fn(x, y)
val_and_grads_fn = backprop.val_and_grad_function(fn)
with self.assertRaisesRegexp(
ValueError, 'Cannot differentiate a function that returns None; '
'did you forget to return a value from fn?'):
val_and_grads_fn(x, y)
