[METRIC] all metric move finished

This commit is contained in:
tqchen
2015-12-31 04:36:41 -08:00
parent dedd87662b
commit b4d0bb5a6d
17 changed files with 784 additions and 770 deletions

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/*!
* Copyright 2015 by Contributors
* \file elementwise_metric.cc
* \brief evaluation metrics for elementwise binary or regression.
* \author Kailong Chen, Tianqi Chen
*/
#include <xgboost/metric.h>
#include <xgboost/sync.h>
#include <cmath>
#include "../common/math.h"
namespace xgboost {
namespace metric {
/*!
* \brief base class of element-wise evaluation
* \tparam Derived the name of subclass
*/
template<typename Derived>
struct EvalEWiseBase : public Metric {
float Eval(const std::vector<float>& preds,
const MetaInfo& info,
bool distributed) const override {
CHECK_NE(info.labels.size(), 0) << "label set cannot be empty";
CHECK_EQ(preds.size(), info.labels.size())
<< "label and prediction size not match, "
<< "hint: use merror or mlogloss for multi-class classification";
const bst_omp_uint ndata = static_cast<bst_omp_uint>(info.labels.size());
float sum = 0.0, wsum = 0.0;
#pragma omp parallel for reduction(+: sum, wsum) schedule(static)
for (bst_omp_uint i = 0; i < ndata; ++i) {
const float wt = info.GetWeight(i);
sum += Derived::EvalRow(info.labels[i], preds[i]) * wt;
wsum += wt;
}
float dat[2]; dat[0] = sum, dat[1] = wsum;
if (distributed) {
rabit::Allreduce<rabit::op::Sum>(dat, 2);
}
return Derived::GetFinal(dat[0], dat[1]);
}
/*!
* \brief to be implemented by subclass,
* get evaluation result from one row
* \param label label of current instance
* \param pred prediction value of current instance
*/
inline static float EvalRow(float label, float pred);
/*!
* \brief to be overridden by subclass, final transformation
* \param esum the sum statistics returned by EvalRow
* \param wsum sum of weight
*/
inline static float GetFinal(float esum, float wsum) {
return esum / wsum;
}
};
struct EvalRMSE : public EvalEWiseBase<EvalRMSE> {
const char *Name() const override {
return "rmse";
}
inline static float EvalRow(float label, float pred) {
float diff = label - pred;
return diff * diff;
}
inline static float GetFinal(float esum, float wsum) {
return std::sqrt(esum / wsum);
}
};
struct EvalLogLoss : public EvalEWiseBase<EvalLogLoss> {
const char *Name() const override {
return "logloss";
}
inline static float EvalRow(float y, float py) {
const float eps = 1e-16f;
const float pneg = 1.0f - py;
if (py < eps) {
return -y * std::log(eps) - (1.0f - y) * std::log(1.0f - eps);
} else if (pneg < eps) {
return -y * std::log(1.0f - eps) - (1.0f - y) * std::log(eps);
} else {
return -y * std::log(py) - (1.0f - y) * std::log(pneg);
}
}
};
struct EvalError : public EvalEWiseBase<EvalError> {
const char *Name() const override {
return "error";
}
inline static float EvalRow(float label, float pred) {
// assume label is in [0,1]
return pred > 0.5f ? 1.0f - label : label;
}
};
struct EvalPoissionNegLogLik : public EvalEWiseBase<EvalPoissionNegLogLik> {
const char *Name() const override {
return "poisson-nloglik";
}
inline static float EvalRow(float y, float py) {
const float eps = 1e-16f;
if (py < eps) py = eps;
return common::LogGamma(y + 1.0f) + py - std::log(py) * y;
}
};
XGBOOST_REGISTER_METRIC(RMSE, "rmse")
.describe("Rooted mean square error.")
.set_body([](const char* param) { return new EvalRMSE(); });
XGBOOST_REGISTER_METRIC(LogLoss, "logloss")
.describe("Negative loglikelihood for logistic regression.")
.set_body([](const char* param) { return new EvalLogLoss(); });
XGBOOST_REGISTER_METRIC(Error, "error")
.describe("Binary classification error.")
.set_body([](const char* param) { return new EvalError(); });
XGBOOST_REGISTER_METRIC(PossionNegLoglik, "poisson-nloglik")
.describe("Negative loglikelihood for poisson regression.")
.set_body([](const char* param) { return new EvalPoissionNegLogLik(); });
} // namespace metric
} // namespace xgboost

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/*!
* Copyright 2015 by Contributors
* \file multiclass_metric.cc
* \brief evaluation metrics for multiclass classification.
* \author Kailong Chen, Tianqi Chen
*/
#include <xgboost/metric.h>
#include <xgboost/sync.h>
#include <cmath>
#include "../common/math.h"
namespace xgboost {
namespace metric {
/*!
* \brief base class of multi-class evaluation
* \tparam Derived the name of subclass
*/
template<typename Derived>
struct EvalMClassBase : public Metric {
float Eval(const std::vector<float> &preds,
const MetaInfo &info,
bool distributed) const override {
CHECK_NE(info.labels.size(), 0) << "label set cannot be empty";
CHECK(preds.size() % info.labels.size() == 0)
<< "label and prediction size not match";
const size_t nclass = preds.size() / info.labels.size();
CHECK_GE(nclass, 1)
<< "mlogloss and merror are only used for multi-class classification,"
<< " use logloss for binary classification";
const bst_omp_uint ndata = static_cast<bst_omp_uint>(info.labels.size());
float sum = 0.0, wsum = 0.0;
int label_error = 0;
#pragma omp parallel for reduction(+: sum, wsum) schedule(static)
for (bst_omp_uint i = 0; i < ndata; ++i) {
const float wt = info.GetWeight(i);
int label = static_cast<int>(info.labels[i]);
if (label >= 0 && label < static_cast<int>(nclass)) {
sum += Derived::EvalRow(label,
dmlc::BeginPtr(preds) + i * nclass,
nclass) * wt;
wsum += wt;
} else {
label_error = label;
}
}
CHECK(label_error >= 0 && label_error < static_cast<int>(nclass))
<< "MultiClassEvaluation: label must be in [0, num_class),"
<< " num_class=" << nclass << " but found " << label_error << " in label";
float dat[2]; dat[0] = sum, dat[1] = wsum;
if (distributed) {
rabit::Allreduce<rabit::op::Sum>(dat, 2);
}
return Derived::GetFinal(dat[0], dat[1]);
}
/*!
* \brief to be implemented by subclass,
* get evaluation result from one row
* \param label label of current instance
* \param pred prediction value of current instance
* \param nclass number of class in the prediction
*/
inline static float EvalRow(int label,
const float *pred,
size_t nclass);
/*!
* \brief to be overridden by subclass, final transformation
* \param esum the sum statistics returned by EvalRow
* \param wsum sum of weight
*/
inline static float GetFinal(float esum, float wsum) {
return esum / wsum;
}
// used to store error message
const char *error_msg_;
};
/*! \brief match error */
struct EvalMatchError : public EvalMClassBase<EvalMatchError> {
const char* Name() const override {
return "merror";
}
inline static float EvalRow(int label,
const float *pred,
size_t nclass) {
return common::FindMaxIndex(pred, pred + nclass) != pred + static_cast<int>(label);
}
};
/*! \brief match error */
struct EvalMultiLogLoss : public EvalMClassBase<EvalMultiLogLoss> {
const char* Name() const override {
return "mlogloss";
}
inline static float EvalRow(int label,
const float *pred,
size_t nclass) {
const float eps = 1e-16f;
size_t k = static_cast<size_t>(label);
if (pred[k] > eps) {
return -std::log(pred[k]);
} else {
return -std::log(eps);
}
}
};
XGBOOST_REGISTER_METRIC(MatchError, "merror")
.describe("Multiclass classification error.")
.set_body([](const char* param) { return new EvalMatchError(); });
XGBOOST_REGISTER_METRIC(MultiLogLoss, "mlogloss")
.describe("Multiclass negative loglikelihood.")
.set_body([](const char* param) { return new EvalMultiLogLoss(); });
} // namespace metric
} // namespace xgboost

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src/metric/rank_metric.cc Normal file
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/*!
* Copyright 2015 by Contributors
* \file rank_metric.cc
* \brief prediction rank based metrics.
* \author Kailong Chen, Tianqi Chen
*/
#include <xgboost/metric.h>
#include <xgboost/sync.h>
#include <cmath>
#include "../common/math.h"
namespace xgboost {
namespace metric {
/*! \brief AMS: also records best threshold */
struct EvalAMS : public Metric {
public:
explicit EvalAMS(const char* param) {
CHECK(param != nullptr)
<< "AMS must be in format ams@k";
ratio_ = atof(param);
std::ostringstream os;
os << "ams@" << ratio_;
name_ = os.str();
}
float Eval(const std::vector<float> &preds,
const MetaInfo &info,
bool distributed) const override {
CHECK(!distributed) << "metric AMS do not support distributed evaluation";
using namespace std; // NOLINT(*)
const bst_omp_uint ndata = static_cast<bst_omp_uint>(info.labels.size());
CHECK_EQ(info.weights.size(), ndata) << "we need weight to evaluate ams";
std::vector<std::pair<float, unsigned> > rec(ndata);
#pragma omp parallel for schedule(static)
for (bst_omp_uint i = 0; i < ndata; ++i) {
rec[i] = std::make_pair(preds[i], i);
}
std::sort(rec.begin(), rec.end(), common::CmpFirst);
unsigned ntop = static_cast<unsigned>(ratio_ * ndata);
if (ntop == 0) ntop = ndata;
const double br = 10.0;
unsigned thresindex = 0;
double s_tp = 0.0, b_fp = 0.0, tams = 0.0;
for (unsigned i = 0; i < static_cast<unsigned>(ndata-1) && i < ntop; ++i) {
const unsigned ridx = rec[i].second;
const float wt = info.weights[ridx];
if (info.labels[ridx] > 0.5f) {
s_tp += wt;
} else {
b_fp += wt;
}
if (rec[i].first != rec[i + 1].first) {
double ams = sqrt(2 * ((s_tp + b_fp + br) * log(1.0 + s_tp / (b_fp + br)) - s_tp));
if (tams < ams) {
thresindex = i;
tams = ams;
}
}
}
if (ntop == ndata) {
LOG(INFO) << "best-ams-ratio=" << static_cast<float>(thresindex) / ndata;
return static_cast<float>(tams);
} else {
return static_cast<float>(
sqrt(2 * ((s_tp + b_fp + br) * log(1.0 + s_tp/(b_fp + br)) - s_tp)));
}
}
const char* Name() const override {
return name_.c_str();
}
private:
std::string name_;
float ratio_;
};
/*! \brief Area Under Curve, for both classification and rank */
struct EvalAuc : public Metric {
float Eval(const std::vector<float> &preds,
const MetaInfo &info,
bool distributed) const override {
CHECK_NE(info.labels.size(), 0) << "label set cannot be empty";
CHECK_EQ(preds.size(), info.labels.size())
<< "label size predict size not match";
std::vector<unsigned> tgptr(2, 0);
tgptr[1] = static_cast<unsigned>(info.labels.size());
const std::vector<unsigned> &gptr = info.group_ptr.size() == 0 ? tgptr : info.group_ptr;
CHECK_EQ(gptr.back(), info.labels.size())
<< "EvalAuc: group structure must match number of prediction";
const bst_omp_uint ngroup = static_cast<bst_omp_uint>(gptr.size() - 1);
// sum statistics
double sum_auc = 0.0f;
#pragma omp parallel reduction(+:sum_auc)
{
// each thread takes a local rec
std::vector< std::pair<float, unsigned> > rec;
#pragma omp for schedule(static)
for (bst_omp_uint k = 0; k < ngroup; ++k) {
rec.clear();
for (unsigned j = gptr[k]; j < gptr[k + 1]; ++j) {
rec.push_back(std::make_pair(preds[j], j));
}
std::sort(rec.begin(), rec.end(), common::CmpFirst);
// calculate AUC
double sum_pospair = 0.0;
double sum_npos = 0.0, sum_nneg = 0.0, buf_pos = 0.0, buf_neg = 0.0;
for (size_t j = 0; j < rec.size(); ++j) {
const float wt = info.GetWeight(rec[j].second);
const float ctr = info.labels[rec[j].second];
// keep bucketing predictions in same bucket
if (j != 0 && rec[j].first != rec[j - 1].first) {
sum_pospair += buf_neg * (sum_npos + buf_pos *0.5);
sum_npos += buf_pos;
sum_nneg += buf_neg;
buf_neg = buf_pos = 0.0f;
}
buf_pos += ctr * wt;
buf_neg += (1.0f - ctr) * wt;
}
sum_pospair += buf_neg * (sum_npos + buf_pos *0.5);
sum_npos += buf_pos;
sum_nneg += buf_neg;
// check weird conditions
CHECK(sum_npos > 0.0 && sum_nneg > 0.0)
<< "AUC: the dataset only contains pos or neg samples";
// this is the AUC
sum_auc += sum_pospair / (sum_npos*sum_nneg);
}
}
if (distributed) {
float dat[2];
dat[0] = static_cast<float>(sum_auc);
dat[1] = static_cast<float>(ngroup);
// approximately estimate auc using mean
rabit::Allreduce<rabit::op::Sum>(dat, 2);
return dat[0] / dat[1];
} else {
return static_cast<float>(sum_auc) / ngroup;
}
}
const char* Name() const override {
return "auc";
}
};
/*! \brief Evaluate rank list */
struct EvalRankList : public Metric {
public:
float Eval(const std::vector<float> &preds,
const MetaInfo &info,
bool distributed) const override {
CHECK_EQ(preds.size(), info.labels.size())
<< "label size predict size not match";
// quick consistency when group is not available
std::vector<unsigned> tgptr(2, 0);
tgptr[1] = static_cast<unsigned>(preds.size());
const std::vector<unsigned> &gptr = info.group_ptr.size() == 0 ? tgptr : info.group_ptr;
CHECK_NE(gptr.size(), 0) << "must specify group when constructing rank file";
CHECK_EQ(gptr.back(), preds.size())
<< "EvalRanklist: group structure must match number of prediction";
const bst_omp_uint ngroup = static_cast<bst_omp_uint>(gptr.size() - 1);
// sum statistics
double sum_metric = 0.0f;
#pragma omp parallel reduction(+:sum_metric)
{
// each thread takes a local rec
std::vector< std::pair<float, unsigned> > rec;
#pragma omp for schedule(static)
for (bst_omp_uint k = 0; k < ngroup; ++k) {
rec.clear();
for (unsigned j = gptr[k]; j < gptr[k + 1]; ++j) {
rec.push_back(std::make_pair(preds[j], static_cast<int>(info.labels[j])));
}
sum_metric += this->EvalMetric(rec);
}
}
if (distributed) {
float dat[2];
dat[0] = static_cast<float>(sum_metric);
dat[1] = static_cast<float>(ngroup);
// approximately estimate the metric using mean
rabit::Allreduce<rabit::op::Sum>(dat, 2);
return dat[0] / dat[1];
} else {
return static_cast<float>(sum_metric) / ngroup;
}
}
const char* Name() const override {
return name_.c_str();
}
protected:
explicit EvalRankList(const char* name, const char* param) {
using namespace std; // NOLINT(*)
minus_ = false;
if (param != nullptr) {
std::ostringstream os;
os << name << '@' << param;
name_ = os.str();
if (sscanf(param, "%u[-]?", &topn_) != 1) {
topn_ = std::numeric_limits<unsigned>::max();
}
if (param[strlen(param) - 1] == '-') {
minus_ = true;
}
} else {
topn_ = std::numeric_limits<unsigned>::max();
}
}
/*! \return evaluation metric, given the pair_sort record, (pred,label) */
virtual float EvalMetric(std::vector<std::pair<float, unsigned> > &pair_sort) const = 0; // NOLINT(*)
protected:
unsigned topn_;
std::string name_;
bool minus_;
};
/*! \brief Precision at N, for both classification and rank */
struct EvalPrecision : public EvalRankList{
public:
explicit EvalPrecision(const char *name) : EvalRankList("pre", name) {}
protected:
virtual float EvalMetric(std::vector< std::pair<float, unsigned> > &rec) const {
// calculate Precision
std::sort(rec.begin(), rec.end(), common::CmpFirst);
unsigned nhit = 0;
for (size_t j = 0; j < rec.size() && j < this->topn_; ++j) {
nhit += (rec[j].second != 0);
}
return static_cast<float>(nhit) / topn_;
}
};
/*! \brief NDCG: Normalized Discounted Cumulative Gain at N */
struct EvalNDCG : public EvalRankList{
public:
explicit EvalNDCG(const char *name) : EvalRankList("ndcg", name) {}
protected:
inline float CalcDCG(const std::vector<std::pair<float, unsigned> > &rec) const {
double sumdcg = 0.0;
for (size_t i = 0; i < rec.size() && i < this->topn_; ++i) {
const unsigned rel = rec[i].second;
if (rel != 0) {
sumdcg += ((1 << rel) - 1) / std::log(i + 2.0);
}
}
return static_cast<float>(sumdcg);
}
virtual float EvalMetric(std::vector<std::pair<float, unsigned> > &rec) const { // NOLINT(*)
std::stable_sort(rec.begin(), rec.end(), common::CmpFirst);
float dcg = this->CalcDCG(rec);
std::stable_sort(rec.begin(), rec.end(), common::CmpSecond);
float idcg = this->CalcDCG(rec);
if (idcg == 0.0f) {
if (minus_) {
return 0.0f;
} else {
return 1.0f;
}
}
return dcg/idcg;
}
};
/*! \brief Mean Average Precision at N, for both classification and rank */
struct EvalMAP : public EvalRankList {
public:
explicit EvalMAP(const char *name) : EvalRankList("map", name) {}
protected:
virtual float EvalMetric(std::vector< std::pair<float, unsigned> > &rec) const {
std::sort(rec.begin(), rec.end(), common::CmpFirst);
unsigned nhits = 0;
double sumap = 0.0;
for (size_t i = 0; i < rec.size(); ++i) {
if (rec[i].second != 0) {
nhits += 1;
if (i < this->topn_) {
sumap += static_cast<float>(nhits) / (i + 1);
}
}
}
if (nhits != 0) {
sumap /= nhits;
return static_cast<float>(sumap);
} else {
if (minus_) {
return 0.0f;
} else {
return 1.0f;
}
}
}
};
XGBOOST_REGISTER_METRIC(AMS, "ams")
.describe("AMS metric for higgs.")
.set_body([](const char* param) { return new EvalAMS(param); });
XGBOOST_REGISTER_METRIC(Auc, "auc")
.describe("Area under curve for both classification and rank.")
.set_body([](const char* param) { return new EvalAuc(); });
XGBOOST_REGISTER_METRIC(Precision, "pre")
.describe("precision@k for rank.")
.set_body([](const char* param) { return new EvalPrecision(param); });
XGBOOST_REGISTER_METRIC(NDCG, "ndcg")
.describe("ndcg@k for rank.")
.set_body([](const char* param) { return new EvalNDCG(param); });
XGBOOST_REGISTER_METRIC(MAP, "map")
.describe("map@k for rank.")
.set_body([](const char* param) { return new EvalMAP(param); });
} // namespace metric
} // namespace xgboost