xgboost/src/objective/hinge.cu
Jiaming Yuan 5b1161bb64
Convert labels into tensor. (#7456)
* Add a new ctor to tensor for `initilizer_list`.
* Change labels from host device vector to tensor.
* Rename the field from `labels_` to `labels` since it's a public member.
2021-12-17 00:58:35 +08:00

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/*!
* Copyright 2018-2019 by Contributors
* \file hinge.cc
* \brief Provides an implementation of the hinge loss function
* \author Henry Gouk
*/
#include "xgboost/objective.h"
#include "xgboost/json.h"
#include "xgboost/span.h"
#include "xgboost/host_device_vector.h"
#include "../common/math.h"
#include "../common/transform.h"
#include "../common/common.h"
namespace xgboost {
namespace obj {
#if defined(XGBOOST_USE_CUDA)
DMLC_REGISTRY_FILE_TAG(hinge_obj_gpu);
#endif // defined(XGBOOST_USE_CUDA)
class HingeObj : public ObjFunction {
public:
HingeObj() = default;
void Configure(
const std::vector<std::pair<std::string, std::string> > &args) override {}
ObjInfo Task() const override { return {ObjInfo::kRegression, false}; }
void GetGradient(const HostDeviceVector<bst_float> &preds,
const MetaInfo &info,
int iter,
HostDeviceVector<GradientPair> *out_gpair) override {
CHECK_NE(info.labels.Size(), 0U) << "label set cannot be empty";
CHECK_EQ(preds.Size(), info.labels.Size())
<< "labels are not correctly provided"
<< "preds.size=" << preds.Size()
<< ", label.size=" << info.labels.Size();
const size_t ndata = preds.Size();
const bool is_null_weight = info.weights_.Size() == 0;
if (!is_null_weight) {
CHECK_EQ(info.weights_.Size(), ndata)
<< "Number of weights should be equal to number of data points.";
}
out_gpair->Resize(ndata);
common::Transform<>::Init(
[=] XGBOOST_DEVICE(size_t _idx,
common::Span<GradientPair> _out_gpair,
common::Span<const bst_float> _preds,
common::Span<const bst_float> _labels,
common::Span<const bst_float> _weights) {
bst_float p = _preds[_idx];
bst_float w = is_null_weight ? 1.0f : _weights[_idx];
bst_float y = _labels[_idx] * 2.0 - 1.0;
bst_float g, h;
if (p * y < 1.0) {
g = -y * w;
h = w;
} else {
g = 0.0;
h = std::numeric_limits<bst_float>::min();
}
_out_gpair[_idx] = GradientPair(g, h);
},
common::Range{0, static_cast<int64_t>(ndata)},
tparam_->gpu_id).Eval(
out_gpair, &preds, info.labels.Data(), &info.weights_);
}
void PredTransform(HostDeviceVector<bst_float> *io_preds) const override {
common::Transform<>::Init(
[] XGBOOST_DEVICE(size_t _idx, common::Span<bst_float> _preds) {
_preds[_idx] = _preds[_idx] > 0.0 ? 1.0 : 0.0;
},
common::Range{0, static_cast<int64_t>(io_preds->Size()), 1},
io_preds->DeviceIdx())
.Eval(io_preds);
}
const char* DefaultEvalMetric() const override {
return "error";
}
void SaveConfig(Json* p_out) const override {
auto& out = *p_out;
out["name"] = String("binary:hinge");
}
void LoadConfig(Json const& in) override {}
};
// register the objective functions
XGBOOST_REGISTER_OBJECTIVE(HingeObj, "binary:hinge")
.describe("Hinge loss. Expects labels to be in [0,1f]")
.set_body([]() { return new HingeObj(); });
} // namespace obj
} // namespace xgboost