Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

PREP: migrate lgamma gradient to c++ side #12720

Merged
merged 6 commits into from
Sep 8, 2017
Merged

PREP: migrate lgamma gradient to c++ side #12720

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
3a93953
ENH: migrate LgammaGrad to c side
facaiy Aug 31, 2017
af72384
CLN: typo, output -> input
facaiy Sep 4, 2017
fefa6d2
TST: add unit test
facaiy Sep 4, 2017
fe48780
merge master from upstream
facaiy Sep 4, 2017
22e1e2f
CLN: typo
facaiy Sep 4, 2017
f7b8c38
TST: add note for complex values
facaiy Sep 4, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
12 changes: 12 additions & 0 deletions tensorflow/cc/gradients/math_grad.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -687,6 +687,18 @@ Status MeanGrad(const Scope& scope, const Operation& op,
}
REGISTER_GRADIENT_OP("Mean", MeanGrad);

Status LgammaGrad(const Scope& scope, const Operation& op,
const std::vector<Output>& grad_inputs,
std::vector<Output>* grad_outputs) {
auto grad = grad_inputs[0];
Scope grad_scope = scope.WithControlDependencies(grad);
auto x = ConjugateHelper(grad_scope, op.input(0));
auto dx = Mul(scope, grad, Digamma(scope, x));
grad_outputs->push_back(dx);
return scope.status();
}
REGISTER_GRADIENT_OP("Lgamma", LgammaGrad);

Status MinOrMaxGrad(const Scope& scope, const Operation& op,
const std::vector<Output>& grad_inputs,
std::vector<Output>* grad_outputs) {
Expand Down
12 changes: 12 additions & 0 deletions tensorflow/cc/gradients/math_grad_test.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1091,5 +1091,17 @@ TEST_F(NaryGradTest, Minimum) {
RunTest(x, x_init_value, y, shape);
}

TEST_F(NaryGradTest, Lgamma) {
TensorShape shape({3, 2});
auto x = Placeholder(scope_, DT_FLOAT, Placeholder::Shape(shape));
auto y = Lgamma(scope_, x);
// Select values to avoid instability when computing finite differences.
// Ref: https://en.wikipedia.org/wiki/File:Gamma_plot.svg
Tensor x_init_value =
test::AsTensor<float>({-3.5f, -2.5f, -1.5f, 1.0f, 2.0f, 3.5f}, {3, 2});
Copy link
Member Author

@facaiy facaiy Sep 4, 2017 •
edited

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Since lgamma is the log of the absolute value of Gamma(x), the values are referred from Wiki:

RunTest(x, x_init_value, y, shape);
// TODO(suharshs): add test case for complex values
}

} // namespace
} // namespace tensorflow