Added loss_epsilon_insensitive_ layer

This commit is contained in:
Davis King 2017-11-10 18:10:51 -05:00
parent 6137540b27
commit 2b0a4a6f6d
3 changed files with 279 additions and 0 deletions

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@ -1677,6 +1677,137 @@ namespace dlib
template <typename SUBNET>
using loss_mean_squared = add_loss_layer<loss_mean_squared_, SUBNET>;
// ----------------------------------------------------------------------------------------
class loss_epsilon_insensitive_
{
public:
typedef float training_label_type;
typedef float output_label_type;
loss_epsilon_insensitive_() = default;
loss_epsilon_insensitive_(double eps) : eps(eps)
{
DLIB_CASSERT(eps >= 0, "You can't set a negative error epsilon.");
}
double get_epsilon () const { return eps; }
void set_epsilon(double e)
{
DLIB_CASSERT(e >= 0, "You can't set a negative error epsilon.");
eps = e;
}
template <
typename SUB_TYPE,
typename label_iterator
>
void to_label (
const tensor& input_tensor,
const SUB_TYPE& sub,
label_iterator iter
) const
{
DLIB_CASSERT(sub.sample_expansion_factor() == 1);
const tensor& output_tensor = sub.get_output();
DLIB_CASSERT(output_tensor.nr() == 1 &&
output_tensor.nc() == 1 &&
output_tensor.k() == 1);
DLIB_CASSERT(input_tensor.num_samples() == output_tensor.num_samples());
const float* out_data = output_tensor.host();
for (long i = 0; i < output_tensor.num_samples(); ++i)
{
*iter++ = out_data[i];
}
}
template <
typename const_label_iterator,
typename SUBNET
>
double compute_loss_value_and_gradient (
const tensor& input_tensor,
const_label_iterator truth,
SUBNET& sub
) const
{
const tensor& output_tensor = sub.get_output();
tensor& grad = sub.get_gradient_input();
DLIB_CASSERT(sub.sample_expansion_factor() == 1);
DLIB_CASSERT(input_tensor.num_samples() != 0);
DLIB_CASSERT(input_tensor.num_samples()%sub.sample_expansion_factor() == 0);
DLIB_CASSERT(input_tensor.num_samples() == grad.num_samples());
DLIB_CASSERT(input_tensor.num_samples() == output_tensor.num_samples());
DLIB_CASSERT(output_tensor.nr() == 1 &&
output_tensor.nc() == 1 &&
output_tensor.k() == 1);
DLIB_CASSERT(grad.nr() == 1 &&
grad.nc() == 1 &&
grad.k() == 1);
// The loss we output is the average loss over the mini-batch.
const double scale = 1.0/output_tensor.num_samples();
double loss = 0;
float* g = grad.host_write_only();
const float* out_data = output_tensor.host();
for (long i = 0; i < output_tensor.num_samples(); ++i)
{
const float y = *truth++;
const float err = out_data[i]-y;
if (err > eps)
{
loss += scale*(err-eps);
g[i] = scale;
}
else if (err < -eps)
{
loss += scale*(eps-err);
g[i] = -scale;
}
}
return loss;
}
friend void serialize(const loss_epsilon_insensitive_& item, std::ostream& out)
{
serialize("loss_epsilon_insensitive_", out);
serialize(item.eps, out);
}
friend void deserialize(loss_epsilon_insensitive_& item, std::istream& in)
{
std::string version;
deserialize(version, in);
if (version != "loss_epsilon_insensitive_")
throw serialization_error("Unexpected version found while deserializing dlib::loss_epsilon_insensitive_.");
deserialize(item.eps, in);
}
friend std::ostream& operator<<(std::ostream& out, const loss_epsilon_insensitive_& item)
{
out << "loss_epsilon_insensitive epsilon: " << item.eps;
return out;
}
friend void to_xml(const loss_epsilon_insensitive_& item, std::ostream& out)
{
out << "<loss_epsilon_insensitive_ epsilon='" << item.eps << "'/>";
}
private:
double eps = 1;
};
template <typename SUBNET>
using loss_epsilon_insensitive = add_loss_layer<loss_epsilon_insensitive_, SUBNET>;
// ----------------------------------------------------------------------------------------
class loss_mean_squared_multioutput_

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@ -779,6 +779,106 @@ namespace dlib
template <typename SUBNET>
using loss_ranking = add_loss_layer<loss_ranking_, SUBNET>;
// ----------------------------------------------------------------------------------------
class loss_epsilon_insensitive_
{
/*!
WHAT THIS OBJECT REPRESENTS
This object implements the loss layer interface defined above by
EXAMPLE_LOSS_LAYER_. In particular, it implements the epsilon insensitive
loss, which is appropriate for regression problems. In particular, this
loss function is;
loss(y1,y2) = abs(y1-y2)<epsilon ? 0 : abs(y1-y2)-epsilon
Therefore, the loss is basically just the abs() loss except there is a dead
zone around zero, causing the loss to not care about mistakes of magnitude
smaller than epsilon.
!*/
public:
typedef float training_label_type;
typedef float output_label_type;
loss_epsilon_insensitive_(
) = default;
/*!
ensures
- #get_epsilon() == 1
!*/
loss_epsilon_insensitive_(
double eps
);
/*!
requires
- eps >= 0
ensures
- #get_epsilon() == eps
!*/
double get_epsilon (
) const;
/*!
ensures
- returns the epsilon value used in the loss function. Mistakes in the
regressor smaller than get_epsilon() are ignored by the loss function.
!*/
void set_epsilon(
double eps
);
/*!
requires
- eps >= 0
ensures
- #get_epsilon() == eps
!*/
template <
typename SUB_TYPE,
typename label_iterator
>
void to_label (
const tensor& input_tensor,
const SUB_TYPE& sub,
label_iterator iter
) const;
/*!
This function has the same interface as EXAMPLE_LOSS_LAYER_::to_label() except
it has the additional calling requirements that:
- sub.get_output().nr() == 1
- sub.get_output().nc() == 1
- sub.get_output().k() == 1
- sub.get_output().num_samples() == input_tensor.num_samples()
- sub.sample_expansion_factor() == 1
and the output label is the predicted continuous variable.
!*/
template <
typename const_label_iterator,
typename SUBNET
>
double compute_loss_value_and_gradient (
const tensor& input_tensor,
const_label_iterator truth,
SUBNET& sub
) const;
/*!
This function has the same interface as EXAMPLE_LOSS_LAYER_::compute_loss_value_and_gradient()
except it has the additional calling requirements that:
- sub.get_output().nr() == 1
- sub.get_output().nc() == 1
- sub.get_output().k() == 1
- sub.get_output().num_samples() == input_tensor.num_samples()
- sub.sample_expansion_factor() == 1
!*/
};
template <typename SUBNET>
using loss_epsilon_insensitive = add_loss_layer<loss_epsilon_insensitive_, SUBNET>;
// ----------------------------------------------------------------------------------------
class loss_mean_squared_

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@ -2116,6 +2116,53 @@ namespace
}
// ----------------------------------------------------------------------------------------
void test_simple_linear_regression_eil()
{
print_spinner();
const int num_samples = 1000;
::std::vector<matrix<double>> x(num_samples);
::std::vector<float> y(num_samples);
::std::default_random_engine generator(16);
::std::normal_distribution<float> distribution(0,0.0001);
const float true_intercept = 50.0;
const float true_slope = 10.0;
for ( int ii = 0; ii < num_samples; ++ii )
{
const double val = static_cast<double>(ii)/10;
matrix<double> tmp(1,1);
tmp = val;
x[ii] = tmp;
y[ii] = (true_intercept + true_slope*static_cast<float>(val) + distribution(generator));
}
using net_type = loss_epsilon_insensitive<fc<1, input<matrix<double>>>>;
net_type net(0.01);
layer<1>(net).layer_details().set_bias_learning_rate_multiplier(300);
sgd defsolver(0,0.9);
dnn_trainer<net_type> trainer(net, defsolver);
trainer.set_learning_rate(1e-5);
trainer.set_min_learning_rate(1e-8);
trainer.set_mini_batch_size(50);
trainer.set_max_num_epochs(570);
trainer.train(x, y);
const float slope = layer<1>(net).layer_details().get_weights().host()[0];
const float slope_error = abs(true_slope - slope);
const float intercept = layer<1>(net).layer_details().get_biases().host()[0];
const float intercept_error = abs(true_intercept - intercept);
const float eps_slope = 0.01, eps_intercept = 0.1;
dlog << LINFO << "slope_error: "<< slope_error;
dlog << LINFO << "intercept_error: "<< intercept_error;
DLIB_TEST_MSG(slope_error <= eps_slope,
"Expected slope = " << true_slope << " Estimated slope = " << slope << " Error limit = " << eps_slope);
DLIB_TEST_MSG(intercept_error <= eps_intercept,
"Expected intercept = " << true_intercept << " Estimated intercept = " << intercept << " Error limit = " << eps_intercept);
}
// ----------------------------------------------------------------------------------------
void test_simple_linear_regression_with_mult_prev()
@ -2950,6 +2997,7 @@ namespace
test_copy_tensor_add_to_cpu();
test_concat();
test_simple_linear_regression();
test_simple_linear_regression_eil();
test_simple_linear_regression_with_mult_prev();
test_multioutput_linear_regression();
test_simple_autoencoder();