# coding: utf8 from __future__ import division, print_function, unicode_literals import numpy as np from .gold import tags_to_entities, GoldParse from .errors import Errors class PRFScore(object): """ A precision / recall / F score """ def __init__(self): self.tp = 0 self.fp = 0 self.fn = 0 def score_set(self, cand, gold): self.tp += len(cand.intersection(gold)) self.fp += len(cand - gold) self.fn += len(gold - cand) @property def precision(self): return self.tp / (self.tp + self.fp + 1e-100) @property def recall(self): return self.tp / (self.tp + self.fn + 1e-100) @property def fscore(self): p = self.precision r = self.recall return 2 * ((p * r) / (p + r + 1e-100)) class ROCAUCScore(object): """ An AUC ROC score. """ def __init__(self): self.golds = [] self.cands = [] self.saved_score = 0.0 self.saved_score_at_len = 0 def score_set(self, cand, gold): self.cands.append(cand) self.golds.append(gold) @property def score(self): if len(self.golds) == self.saved_score_at_len: return self.saved_score try: self.saved_score = _roc_auc_score(self.golds, self.cands) # catch ValueError: Only one class present in y_true. # ROC AUC score is not defined in that case. except: self.saved_score = -float("inf") self.saved_score_at_len = len(self.golds) return self.saved_score class Scorer(object): """Compute evaluation scores.""" def __init__(self, eval_punct=False, pipeline=None): """Initialize the Scorer. eval_punct (bool): Evaluate the dependency attachments to and from punctuation. RETURNS (Scorer): The newly created object. DOCS: https://spacy.io/api/scorer#init """ self.tokens = PRFScore() self.sbd = PRFScore() self.unlabelled = PRFScore() self.labelled = PRFScore() self.tags = PRFScore() self.ner = PRFScore() self.ner_per_ents = dict() self.eval_punct = eval_punct self.textcat = None self.textcat_per_cat = dict() self.textcat_positive_label = None self.textcat_multilabel = False if pipeline: for name, model in pipeline: if name == "textcat": self.textcat_positive_label = model.cfg.get("positive_label", None) if self.textcat_positive_label: self.textcat = PRFScore() if not model.cfg.get("exclusive_classes", False): self.textcat_multilabel = True for label in model.cfg.get("labels", []): self.textcat_per_cat[label] = ROCAUCScore() else: for label in model.cfg.get("labels", []): self.textcat_per_cat[label] = PRFScore() @property def tags_acc(self): """RETURNS (float): Part-of-speech tag accuracy (fine grained tags, i.e. `Token.tag`). """ return self.tags.fscore * 100 @property def token_acc(self): """RETURNS (float): Tokenization accuracy.""" return self.tokens.precision * 100 @property def uas(self): """RETURNS (float): Unlabelled dependency score.""" return self.unlabelled.fscore * 100 @property def las(self): """RETURNS (float): Labelled depdendency score.""" return self.labelled.fscore * 100 @property def ents_p(self): """RETURNS (float): Named entity accuracy (precision).""" return self.ner.precision * 100 @property def ents_r(self): """RETURNS (float): Named entity accuracy (recall).""" return self.ner.recall * 100 @property def ents_f(self): """RETURNS (float): Named entity accuracy (F-score).""" return self.ner.fscore * 100 @property def ents_per_type(self): """RETURNS (dict): Scores per entity label. """ return { k: {"p": v.precision * 100, "r": v.recall * 100, "f": v.fscore * 100} for k, v in self.ner_per_ents.items() } @property def textcat_score(self): """RETURNS (float): f-score on positive label for binary exclusive, macro-averaged f-score for 3+ exclusive, macro-averaged AUC ROC score for multilabel (-1 if undefined) """ if not self.textcat_multilabel: # binary multiclass if self.textcat_positive_label: return self.textcat.fscore * 100 # other multiclass return ( sum([score.fscore for label, score in self.textcat_per_cat.items()]) / (len(self.textcat_per_cat) + 1e-100) * 100 ) # multilabel return max( sum([score.score for label, score in self.textcat_per_cat.items()]) / (len(self.textcat_per_cat) + 1e-100), -1, ) @property def textcats_per_cat(self): """RETURNS (dict): Scores per textcat label. """ if not self.textcat_multilabel: return { k: {"p": v.precision * 100, "r": v.recall * 100, "f": v.fscore * 100} for k, v in self.textcat_per_cat.items() } return { k: {"roc_auc_score": max(v.score, -1)} for k, v in self.textcat_per_cat.items() } @property def scores(self): """RETURNS (dict): All scores with keys `uas`, `las`, `ents_p`, `ents_r`, `ents_f`, `tags_acc`, `token_acc`, and `textcat_score`. """ return { "uas": self.uas, "las": self.las, "ents_p": self.ents_p, "ents_r": self.ents_r, "ents_f": self.ents_f, "ents_per_type": self.ents_per_type, "tags_acc": self.tags_acc, "token_acc": self.token_acc, "textcat_score": self.textcat_score, "textcats_per_cat": self.textcats_per_cat, } def score(self, doc, gold, verbose=False, punct_labels=("p", "punct")): """Update the evaluation scores from a single Doc / GoldParse pair. doc (Doc): The predicted annotations. gold (GoldParse): The correct annotations. verbose (bool): Print debugging information. punct_labels (tuple): Dependency labels for punctuation. Used to evaluate dependency attachments to punctuation if `eval_punct` is `True`. DOCS: https://spacy.io/api/scorer#score """ if len(doc) != len(gold): gold = GoldParse.from_annot_tuples(doc, zip(*gold.orig_annot)) gold_deps = set() gold_tags = set() gold_ents = set(tags_to_entities([annot[-1] for annot in gold.orig_annot])) for id_, word, tag, head, dep, ner in gold.orig_annot: gold_tags.add((id_, tag)) if dep not in (None, "") and dep.lower() not in punct_labels: gold_deps.add((id_, head, dep.lower())) cand_deps = set() cand_tags = set() for token in doc: if token.orth_.isspace(): continue gold_i = gold.cand_to_gold[token.i] if gold_i is None: self.tokens.fp += 1 else: self.tokens.tp += 1 cand_tags.add((gold_i, token.tag_)) if token.dep_.lower() not in punct_labels and token.orth_.strip(): gold_head = gold.cand_to_gold[token.head.i] # None is indistinct, so we can't just add it to the set # Multiple (None, None) deps are possible if gold_i is None or gold_head is None: self.unlabelled.fp += 1 self.labelled.fp += 1 else: cand_deps.add((gold_i, gold_head, token.dep_.lower())) if "-" not in [token[-1] for token in gold.orig_annot]: # Find all NER labels in gold and doc ent_labels = set([x[0] for x in gold_ents] + [k.label_ for k in doc.ents]) # Set up all labels for per type scoring and prepare gold per type gold_per_ents = {ent_label: set() for ent_label in ent_labels} for ent_label in ent_labels: if ent_label not in self.ner_per_ents: self.ner_per_ents[ent_label] = PRFScore() gold_per_ents[ent_label].update( [x for x in gold_ents if x[0] == ent_label] ) # Find all candidate labels, for all and per type cand_ents = set() cand_per_ents = {ent_label: set() for ent_label in ent_labels} for ent in doc.ents: first = gold.cand_to_gold[ent.start] last = gold.cand_to_gold[ent.end - 1] if first is None or last is None: self.ner.fp += 1 self.ner_per_ents[ent.label_].fp += 1 else: cand_ents.add((ent.label_, first, last)) cand_per_ents[ent.label_].add((ent.label_, first, last)) # Scores per ent for k, v in self.ner_per_ents.items(): if k in cand_per_ents: v.score_set(cand_per_ents[k], gold_per_ents[k]) # Score for all ents self.ner.score_set(cand_ents, gold_ents) self.tags.score_set(cand_tags, gold_tags) self.labelled.score_set(cand_deps, gold_deps) self.unlabelled.score_set( set(item[:2] for item in cand_deps), set(item[:2] for item in gold_deps) ) if ( len(gold.cats) > 0 and set(self.textcat_per_cat) == set(gold.cats) and set(gold.cats) == set(doc.cats) ): goldcat = max(gold.cats, key=gold.cats.get) candcat = max(doc.cats, key=doc.cats.get) if self.textcat_positive_label: self.textcat.score_set( set([self.textcat_positive_label]) & set([candcat]), set([self.textcat_positive_label]) & set([goldcat]), ) for label in self.textcat_per_cat: if self.textcat_multilabel: self.textcat_per_cat[label].score_set( doc.cats[label], gold.cats[label] ) else: self.textcat_per_cat[label].score_set( set([label]) & set([candcat]), set([label]) & set([goldcat]) ) elif len(self.textcat_per_cat) > 0: model_labels = set(self.textcat_per_cat) eval_labels = set(gold.cats) raise ValueError( Errors.E162.format(model_labels=model_labels, eval_labels=eval_labels) ) if verbose: gold_words = [item[1] for item in gold.orig_annot] for w_id, h_id, dep in cand_deps - gold_deps: print("F", gold_words[w_id], dep, gold_words[h_id]) for w_id, h_id, dep in gold_deps - cand_deps: print("M", gold_words[w_id], dep, gold_words[h_id]) ############################################################################# # # The following implementation of roc_auc_score() is adapted from # scikit-learn, which is distributed under the following license: # # New BSD License # # Copyright (c) 2007–2019 The scikit-learn developers. # All rights reserved. # # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions are met: # # a. Redistributions of source code must retain the above copyright notice, # this list of conditions and the following disclaimer. # b. Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # c. Neither the name of the Scikit-learn Developers nor the names of # its contributors may be used to endorse or promote products # derived from this software without specific prior written # permission. # # # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE # ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR # ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH # DAMAGE. def _roc_auc_score(y_true, y_score): """Compute Area Under the Receiver Operating Characteristic Curve (ROC AUC) from prediction scores. Note: this implementation is restricted to the binary classification task Parameters ---------- y_true : array, shape = [n_samples] or [n_samples, n_classes] True binary labels or binary label indicators. The multiclass case expects shape = [n_samples] and labels with values in ``range(n_classes)``. y_score : array, shape = [n_samples] or [n_samples, n_classes] Target scores, can either be probability estimates of the positive class, confidence values, or non-thresholded measure of decisions (as returned by "decision_function" on some classifiers). For binary y_true, y_score is supposed to be the score of the class with greater label. The multiclass case expects shape = [n_samples, n_classes] where the scores correspond to probability estimates. Returns ------- auc : float References ---------- .. [1] `Wikipedia entry for the Receiver operating characteristic `_ .. [2] Fawcett T. An introduction to ROC analysis[J]. Pattern Recognition Letters, 2006, 27(8):861-874. .. [3] `Analyzing a portion of the ROC curve. McClish, 1989 `_ """ if len(np.unique(y_true)) != 2: raise ValueError(Errors.E165) fpr, tpr, _ = _roc_curve(y_true, y_score) return _auc(fpr, tpr) def _roc_curve(y_true, y_score): """Compute Receiver operating characteristic (ROC) Note: this implementation is restricted to the binary classification task. Parameters ---------- y_true : array, shape = [n_samples] True binary labels. If labels are not either {-1, 1} or {0, 1}, then pos_label should be explicitly given. y_score : array, shape = [n_samples] Target scores, can either be probability estimates of the positive class, confidence values, or non-thresholded measure of decisions (as returned by "decision_function" on some classifiers). Returns ------- fpr : array, shape = [>2] Increasing false positive rates such that element i is the false positive rate of predictions with score >= thresholds[i]. tpr : array, shape = [>2] Increasing true positive rates such that element i is the true positive rate of predictions with score >= thresholds[i]. thresholds : array, shape = [n_thresholds] Decreasing thresholds on the decision function used to compute fpr and tpr. `thresholds[0]` represents no instances being predicted and is arbitrarily set to `max(y_score) + 1`. Notes ----- Since the thresholds are sorted from low to high values, they are reversed upon returning them to ensure they correspond to both ``fpr`` and ``tpr``, which are sorted in reversed order during their calculation. References ---------- .. [1] `Wikipedia entry for the Receiver operating characteristic `_ .. [2] Fawcett T. An introduction to ROC analysis[J]. Pattern Recognition Letters, 2006, 27(8):861-874. """ fps, tps, thresholds = _binary_clf_curve(y_true, y_score) # Add an extra threshold position # to make sure that the curve starts at (0, 0) tps = np.r_[0, tps] fps = np.r_[0, fps] thresholds = np.r_[thresholds[0] + 1, thresholds] if fps[-1] <= 0: fpr = np.repeat(np.nan, fps.shape) else: fpr = fps / fps[-1] if tps[-1] <= 0: tpr = np.repeat(np.nan, tps.shape) else: tpr = tps / tps[-1] return fpr, tpr, thresholds def _binary_clf_curve(y_true, y_score): """Calculate true and false positives per binary classification threshold. Parameters ---------- y_true : array, shape = [n_samples] True targets of binary classification y_score : array, shape = [n_samples] Estimated probabilities or decision function Returns ------- fps : array, shape = [n_thresholds] A count of false positives, at index i being the number of negative samples assigned a score >= thresholds[i]. The total number of negative samples is equal to fps[-1] (thus true negatives are given by fps[-1] - fps). tps : array, shape = [n_thresholds <= len(np.unique(y_score))] An increasing count of true positives, at index i being the number of positive samples assigned a score >= thresholds[i]. The total number of positive samples is equal to tps[-1] (thus false negatives are given by tps[-1] - tps). thresholds : array, shape = [n_thresholds] Decreasing score values. """ pos_label = 1. y_true = np.ravel(y_true) y_score = np.ravel(y_score) # make y_true a boolean vector y_true = (y_true == pos_label) # sort scores and corresponding truth values desc_score_indices = np.argsort(y_score, kind="mergesort")[::-1] y_score = y_score[desc_score_indices] y_true = y_true[desc_score_indices] weight = 1. # y_score typically has many tied values. Here we extract # the indices associated with the distinct values. We also # concatenate a value for the end of the curve. distinct_value_indices = np.where(np.diff(y_score))[0] threshold_idxs = np.r_[distinct_value_indices, y_true.size - 1] # accumulate the true positives with decreasing threshold tps = _stable_cumsum(y_true * weight)[threshold_idxs] fps = 1 + threshold_idxs - tps return fps, tps, y_score[threshold_idxs] def _stable_cumsum(arr, axis=None, rtol=1e-05, atol=1e-08): """Use high precision for cumsum and check that final value matches sum Parameters ---------- arr : array-like To be cumulatively summed as flat axis : int, optional Axis along which the cumulative sum is computed. The default (None) is to compute the cumsum over the flattened array. rtol : float Relative tolerance, see ``np.allclose`` atol : float Absolute tolerance, see ``np.allclose`` """ out = np.cumsum(arr, axis=axis, dtype=np.float64) expected = np.sum(arr, axis=axis, dtype=np.float64) if not np.all(np.isclose(out.take(-1, axis=axis), expected, rtol=rtol, atol=atol, equal_nan=True)): raise ValueError(Errors.E163) return out def _auc(x, y): """Compute Area Under the Curve (AUC) using the trapezoidal rule This is a general function, given points on a curve. For computing the area under the ROC-curve, see :func:`roc_auc_score`. Parameters ---------- x : array, shape = [n] x coordinates. These must be either monotonic increasing or monotonic decreasing. y : array, shape = [n] y coordinates. Returns ------- auc : float """ x = np.ravel(x) y = np.ravel(y) direction = 1 dx = np.diff(x) if np.any(dx < 0): if np.all(dx <= 0): direction = -1 else: raise ValueError(Errors.E164.format(x)) area = direction * np.trapz(y, x) if isinstance(area, np.memmap): # Reductions such as .sum used internally in np.trapz do not return a # scalar by default for numpy.memmap instances contrary to # regular numpy.ndarray instances. area = area.dtype.type(area) return area