1/* 2Copyright 2016 The TensorFlow Authors. All Rights Reserved. 3 4Licensed under the Apache License, Version 2.0 (the "License"); 5you may not use this file except in compliance with the License. 6You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10Unless required by applicable law or agreed to in writing, software 11distributed under the License is distributed on an "AS IS" BASIS, 12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13See the License for the specific language governing permissions and 14limitations under the License. 15*/ 16 17package op 18 19import ( 20 "fmt" 21 22 tf "github.com/tensorflow/tensorflow/tensorflow/go" 23) 24 25// Gradients adds gradients computation ops to the graph according to scope. 26// 27// Arguments: 28// y: output of the function to derive 29// x: inputs of the function for which partial derivatives are computed 30// dx: if not null, the partial derivatives of some loss function L w.r.t. y 31// 32// return the partial derivatives 33func Gradients(scope *Scope, y []tf.Output, x []tf.Output, dx ...tf.Output) (output []tf.Output) { 34 if len(scope.controlDependencies) > 0 { 35 scope.UpdateErr("Gradients", fmt.Errorf("Gradients does not currently support control dependencies (via Scope.WithControlDependencies).")) 36 return 37 } 38 if scope.device != "" { 39 scope.UpdateErr("Gradients", fmt.Errorf("Gradients does not currently support device annotations (via Scope.WithDevice).")) 40 return 41 } 42 43 var err error 44 if output, err = scope.graph.AddGradients(scope.opName("Gradients"), y, x, dx); err != nil { 45 scope.UpdateErr("Gradients", err) 46 return 47 } 48 return output 49} 50