// sampleSetSlice converts a sample set into a slice
// of Samples.
func sampleSetSlice(s sgd.SampleSet) []Sample {
res := make([]Sample, s.Len())
for i := 0; i < s.Len(); i++ {
res[i] = s.GetSample(i).(Sample)
}
return res
}
func (b *SingleRGradienter) RGradient(rv autofunc.RVector, s sgd.SampleSet) (autofunc.Gradient,
autofunc.RGradient) {
if b.gradCache == nil {
b.gradCache = autofunc.NewGradient(b.Learner.Parameters())
} else {
b.gradCache.Zero()
}
if b.rgradCache == nil {
b.rgradCache = autofunc.NewRGradient(b.Learner.Parameters())
} else {
b.rgradCache.Zero()
}
for i := 0; i < s.Len(); i++ {
sample := s.GetSample(i)
vs := sample.(VectorSample)
output := vs.Output
inVar := &autofunc.Variable{vs.Input}
rVar := autofunc.NewRVariable(inVar, rv)
result := b.Learner.ApplyR(rv, rVar)
cost := b.CostFunc.CostR(rv, output, result)
cost.PropagateRGradient(linalg.Vector{1}, linalg.Vector{0},
b.rgradCache, b.gradCache)
}
return b.gradCache, b.rgradCache
}
// TotalCost returns the total cost of a layer on a
// set of VectorSamples.
// The elements of s must be VectorSamples.
func TotalCost(c CostFunc, layer autofunc.Func, s sgd.SampleSet) float64 {
var totalCost float64
for i := 0; i < s.Len(); i++ {
sample := s.GetSample(i)
vs := sample.(VectorSample)
inVar := &autofunc.Variable{vs.Input}
result := layer.Apply(inVar)
costOut := c.Cost(vs.Output, result)
totalCost += costOut.Output()[0]
}
return totalCost
}
func countCorrect(n neuralnet.Network, s sgd.SampleSet) int {
var count int
for i := 0; i < s.Len(); i++ {
sample := s.GetSample(i).(neuralnet.VectorSample)
output := n.Apply(&autofunc.Variable{Vector: sample.Input}).Output()
var maxIdx int
var maxVal float64
for j, x := range output {
if x > maxVal || j == 0 {
maxIdx = j
maxVal = x
}
}
if sample.Output[maxIdx] == 1 {
count++
}
}
return count
}
func (b *SingleRGradienter) Gradient(s sgd.SampleSet) autofunc.Gradient {
if b.gradCache == nil {
b.gradCache = autofunc.NewGradient(b.Learner.Parameters())
} else {
b.gradCache.Zero()
}
for i := 0; i < s.Len(); i++ {
sample := s.GetSample(i)
vs := sample.(VectorSample)
output := vs.Output
inVar := &autofunc.Variable{vs.Input}
result := b.Learner.Apply(inVar)
cost := b.CostFunc.Cost(output, result)
cost.PropagateGradient(linalg.Vector{1}, b.gradCache)
}
return b.gradCache
}
func (g *GradHelper) batch(rv autofunc.RVector, s sgd.SampleSet) (grad autofunc.Gradient,
rgrad autofunc.RGradient) {
g.gradCache.variables = g.Learner.Parameters()
if g.lastGradResult != nil {
g.gradCache.Free(g.lastGradResult)
}
if g.lastRGradResult != nil {
g.gradCache.FreeR(g.lastRGradResult)
}
batchSize := g.batchSize()
maxGos := g.goroutineCount()
if s.Len() < batchSize || maxGos < 2 {
grad, rgrad = g.runSync(rv, s)
} else {
grad, rgrad = g.runAsync(rv, s)
}
g.lastGradResult = grad
g.lastRGradResult = rgrad
return
}
func (g *GradHelper) subBatches(s sgd.SampleSet) <-chan sgd.SampleSet {
batchSize := g.batchSize()
res := make(chan sgd.SampleSet, s.Len()/batchSize+1)
for i := 0; i < s.Len(); i += batchSize {
bs := batchSize
if bs > s.Len()-i {
bs = s.Len() - i
}
res <- s.Subset(i, i+bs)
}
close(res)
return res
}
func (b *BatchRGradienter) runBatch(rv autofunc.RVector, rgrad autofunc.RGradient,
grad autofunc.Gradient, s sgd.SampleSet) {
if s.Len() == 0 {
return
}
sampleCount := s.Len()
firstSample := s.GetSample(0).(VectorSample)
inputSize := len(firstSample.Input)
outputSize := len(firstSample.Output)
inVec := make(linalg.Vector, sampleCount*inputSize)
outVec := make(linalg.Vector, sampleCount*outputSize)
for i := 0; i < s.Len(); i++ {
sample := s.GetSample(i)
vs := sample.(VectorSample)
copy(inVec[i*inputSize:], vs.Input)
copy(outVec[i*outputSize:], vs.Output)
}
inVar := &autofunc.Variable{inVec}
if rgrad != nil {
rVar := autofunc.NewRVariable(inVar, rv)
result := b.Learner.BatchR(rv, rVar, sampleCount)
cost := b.CostFunc.CostR(rv, outVec, result)
cost.PropagateRGradient(linalg.Vector{1}, linalg.Vector{0},
rgrad, grad)
} else {
result := b.Learner.Batch(inVar, sampleCount)
cost := b.CostFunc.Cost(outVec, result)
cost.PropagateGradient(linalg.Vector{1}, grad)
}
}
// TotalCostBlock runs an rnn.Block on a set of Samples
// and evaluates the total output cost.
//
// The batchSize specifies how many samples to run in
// batches while computing the cost.
func TotalCostBlock(b rnn.Block, batchSize int, s sgd.SampleSet, c neuralnet.CostFunc) float64 {
runner := &rnn.Runner{Block: b}
var cost float64
for i := 0; i < s.Len(); i += batchSize {
var inSeqs, outSeqs [][]linalg.Vector
for j := i; j < i+batchSize && j < s.Len(); j++ {
seq := s.GetSample(j).(Sample)
inSeqs = append(inSeqs, seq.Inputs)
outSeqs = append(outSeqs, seq.Outputs)
}
output := runner.RunAll(inSeqs)
for j, outSeq := range outSeqs {
for t, actual := range output[j] {
expected := outSeq[t]
actualVar := &autofunc.Variable{Vector: actual}
cost += c.Cost(expected, actualVar).Output()[0]
}
}
}
return cost
}
// TotalCostSeqFunc runs a seqfunc.RFunc on a set of
// Samples and evaluates the total output cost.
//
// The batchSize specifies how many samples to run in
// batches while computing the cost.
func TotalCostSeqFunc(f seqfunc.RFunc, batchSize int, s sgd.SampleSet,
c neuralnet.CostFunc) float64 {
var totalCost float64
for i := 0; i < s.Len(); i += batchSize {
var inSeqs [][]linalg.Vector
var outSeqs [][]linalg.Vector
for j := i; j < i+batchSize && j < s.Len(); j++ {
seq := s.GetSample(j).(Sample)
inSeqs = append(inSeqs, seq.Inputs)
outSeqs = append(outSeqs, seq.Outputs)
}
output := f.ApplySeqs(seqfunc.ConstResult(inSeqs))
for j, actualSeq := range output.OutputSeqs() {
expectedSeq := outSeqs[j]
for k, actual := range actualSeq {
expected := expectedSeq[k]
actualVar := &autofunc.Variable{Vector: actual}
totalCost += c.Cost(expected, actualVar).Output()[0]
}
}
}
return totalCost
}
func createNetwork(samples sgd.SampleSet) *rnn.Bidirectional {
means := make(linalg.Vector, FeatureCount)
var count float64
for i := 0; i < samples.Len(); i++ {
inputSeq := samples.GetSample(i).(ctc.Sample).Input
for _, vec := range inputSeq {
means.Add(vec)
count++
}
}
means.Scale(-1 / count)
stddevs := make(linalg.Vector, FeatureCount)
for i := 0; i < samples.Len(); i++ {
inputSeq := samples.GetSample(i).(ctc.Sample).Input
for _, vec := range inputSeq {
for j, v := range vec {
stddevs[j] += math.Pow(v+means[j], 2)
}
}
}
stddevs.Scale(1 / count)
for i, x := range stddevs {
stddevs[i] = 1 / math.Sqrt(x)
}
outputNet := neuralnet.Network{
&neuralnet.DropoutLayer{
KeepProbability: HiddenDropout,
Training: false,
},
&neuralnet.DenseLayer{
InputCount: HiddenSize * 2,
OutputCount: OutHiddenSize,
},
&neuralnet.HyperbolicTangent{},
&neuralnet.DenseLayer{
InputCount: OutHiddenSize,
OutputCount: len(cubewhisper.Labels) + 1,
},
&neuralnet.LogSoftmaxLayer{},
}
outputNet.Randomize()
inputNet := neuralnet.Network{
&neuralnet.VecRescaleLayer{
Biases: means,
Scales: stddevs,
},
&neuralnet.GaussNoiseLayer{
Stddev: InputNoise,
Training: false,
},
}
netBlock := rnn.NewNetworkBlock(inputNet, 0)
forwardBlock := rnn.StackedBlock{
netBlock,
rnn.NewGRU(FeatureCount, HiddenSize),
}
backwardBlock := rnn.StackedBlock{
netBlock,
rnn.NewGRU(FeatureCount, HiddenSize),
}
for _, block := range []rnn.StackedBlock{forwardBlock, backwardBlock} {
for i, param := range block.Parameters() {
if i%2 == 0 {
for i := range param.Vector {
param.Vector[i] = rand.NormFloat64() * WeightStddev
}
}
}
}
return &rnn.Bidirectional{
Forward: &rnn.BlockSeqFunc{Block: forwardBlock},
Backward: &rnn.BlockSeqFunc{Block: backwardBlock},
Output: &rnn.NetworkSeqFunc{Network: outputNet},
}
}