mat/gradfn/transpose.go
// Copyright 2019 spaGO Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package gradfn
import (
"fmt"
"github.com/nlpodyssey/spago/mat"
)
// Transpose is a Function to calculate the transpose of the matrix-operand.
type Transpose[O mat.Tensor] struct {
x O
}
// NewTranspose returns a new Transpose Function.
func NewTranspose[O mat.Tensor](x O) *Transpose[O] {
return &Transpose[O]{
x: x,
}
}
// Operands returns the list of operands.
func (r *Transpose[O]) Operands() []mat.Tensor {
return []mat.Tensor{r.x}
}
// Forward computes the output of the node.
func (r *Transpose[O]) Forward() (mat.Tensor, error) {
return r.x.Value().(mat.Matrix).T(), nil
}
// Backward computes the backward pass.
func (r *Transpose[O]) Backward(gy mat.Tensor) error {
if r.x.Value().Shape()[1] != gy.Shape()[0] && r.x.Value().Shape()[0] != gy.Shape()[1] {
return fmt.Errorf("fn: matrices have incompatible dimensions")
}
if r.x.RequiresGrad() {
gx := gy.(mat.Matrix).T()
r.x.AccGrad(gx)
}
return nil
}