File size: 15,878 Bytes
d2a8669
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
from aif360.explainers import Explainer
from aif360.metrics import Metric


class MetricTextExplainer(Explainer):
    """Class for explaining metric values with text.

    These briefly explain what a metric is and/or how it is calculated unless it
    is obvious (e.g. accuracy) and print the value.

    This class contains text explanations for all metric values regardless of
    which subclass they appear in. This will raise an error if the metric does
    not apply (e.g. calling `true_positive_rate` if
    `type(metric) == DatasetMetric`).
    """

    def __init__(self, metric):
        """Initialize a `MetricExplainer` object.

        Args:
            metric (Metric): The metric to be explained.
        """
        if isinstance(metric, Metric):
            self.metric = metric
        else:
            raise TypeError("metric must be a Metric.")

    def accuracy(self, privileged=None):
        if privileged is None:
            return "Classification accuracy (ACC): {}".format(
                self.metric.accuracy(privileged=privileged))
        return "Classification accuracy on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.accuracy(privileged=privileged))

    def average_abs_odds_difference(self):
        return ("Average absolute odds difference (average of abs(TPR "
                "difference) and abs(FPR difference)): {}".format(
                    self.metric.average_abs_odds_difference()))

    def average_odds_difference(self):
        return ("Average odds difference (average of TPR difference and FPR "
                "difference, 0 = equality of odds): {}".format(
                    self.metric.average_odds_difference()))

    def between_all_groups_coefficient_of_variation(self):
        return "Between-group coefficient of variation: {}".format(
            self.metric.between_all_groups_coefficient_of_variation())

    def between_all_groups_generalized_entropy_index(self, alpha=2):
        return "Between-group generalized entropy index: {}".format(
            self.metric.between_all_groups_generalized_entropy_index(alpha=alpha))

    def between_all_groups_theil_index(self):
        return "Between-group Theil index: {}".format(
            self.metric.between_all_groups_theil_index())

    def between_group_coefficient_of_variation(self):
        return "Between-group coefficient of variation: {}".format(
            self.metric.between_group_coefficient_of_variation())

    def between_group_generalized_entropy_index(self, alpha=2):
        return "Between-group generalized entropy index: {}".format(
            self.metric.between_group_generalized_entropy_index(alpha=alpha))

    def between_group_theil_index(self):
        return "Between-group Theil index: {}".format(
            self.metric.between_group_theil_index())

    def coefficient_of_variation(self):
        return "Coefficient of variation: {}".format(
            self.metric.coefficient_of_variation())

    def consistency(self, n_neighbors=5):
        return "Consistency (Zemel, et al. 2013): {}".format(
            self.metric.consistency(n_neighbors=n_neighbors))

    def disparate_impact(self):
        return ("Disparate impact (probability of favorable outcome for "
                "unprivileged instances / probability of favorable outcome for "
                "privileged instances): {}".format(
                    self.metric.disparate_impact()))

    def error_rate(self, privileged=None):
        if privileged is None:
            return "Error rate (ERR = 1 - ACC): {}".format(
                self.metric.error_rate(privileged=privileged))
        return "Error rate on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.error_rate(privileged))

    def error_rate_difference(self):
        return ("Error rate difference (error rate on unprivileged instances - "
                "error rate on privileged instances): {}".format(
                    self.metric.error_rate_difference()))

    def error_rate_ratio(self):
        return ("Error rate ratio (error rate on unprivileged instances / "
                "error rate on privileged instances): {}".format(
                    self.metric.error_rate_ratio()))

    def false_discovery_rate(self, privileged=None):
        if privileged is None:
            return "False discovery rate (FDR = FP / (FP + TP)): {}".format(
                self.metric.false_discovery_rate(privileged=privileged))
        return "False discovery rate on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.false_discovery_rate(privileged=privileged))

    def false_discovery_rate_difference(self):
        return ("False discovery rate difference (false discovery rate on "
                "unprivileged instances - false discovery rate on privileged "
                "instances): {}".format(
                    self.metric.false_discovery_rate_difference()))

    def false_discovery_rate_ratio(self):
        return ("False discovery rate ratio (false discovery rate on "
                "unprivileged instances - false discovery rate on privileged "
                "instances): {}".format(
                    self.metric.false_discovery_rate_ratio()))

    def false_negative_rate(self, privileged=None):
        if privileged is None:
            return "False negative rate (FNR = FN / (TP + FN)): {}".format(
                self.metric.false_negative_rate(privileged=privileged))
        return "False negative rate on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.false_negative_rate(privileged=privileged))

    def false_negative_rate_difference(self):
        return ("False negative rate difference (false negative rate on "
                "unprivileged instances - false negative rate on privileged "
                "instances): {}".format(
                    self.metric.false_negative_rate_difference()))

    def false_negative_rate_ratio(self):
        return ("False negative rate ratio (false negative rate on "
                "unprivileged instances / false negative rate on privileged "
                "instances): {}".format(
                    self.metric.false_negative_rate_ratio()))

    def false_omission_rate(self, privileged=None):
        if privileged is None:
            return "False omission rate (FOR = FN / (FN + TN)): {}".format(
                self.metric.false_omission_rate(privileged=privileged))
        return "False omission rate on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.false_omission_rate(privileged=privileged))

    def falses_omission_rate_difference(self):
        return ("False omission rate difference (falses omission rate on "
                "unprivileged instances - falses omission rate on privileged "
                "instances): {}".format(
                    self.metric.falses_omission_rate_difference()))

    def false_omission_rate_ratio(self):
        return ("False omission rate ratio (false omission rate on "
                "unprivileged instances - false omission rate on privileged "
                "instances): {}".format(
                    self.metric.false_omission_rate_ratio()))

    def false_positive_rate(self, privileged=None):
        if privileged is None:
            return "False positive rate (FPR = FP / (FP + TN)): {}".format(
                self.metric.false_positive_rate(privileged=privileged))
        return "False positive rate on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.false_positive_rate(privileged=privileged))

    def false_positive_rate_difference(self):
        return ("False positive rate difference (false positive rate on "
                "unprivileged instances - false positive rate on privileged "
                "instances): {}".format(
                    self.metric.false_positive_rate_difference()))

    def false_positive_rate_ratio(self):
        return ("False positive rate ratio (false positive rate on "
                "unprivileged instances / false positive rate on privileged "
                "instances): {}".format(
                    self.metric.false_positive_rate_ratio()))

    def generalized_entropy_index(self, alpha=2):
        return "Generalized entropy index (GE(alpha)): {}".format(
            self.metric.generalized_entropy_index(alpha=alpha))

    def mean_difference(self):
        return ("Mean difference (mean label value on unprivileged instances - "
                "mean label value on privileged instances): {}".format(
                    self.metric.mean_difference()))

    def negative_predictive_value(self, privileged=None):
        if privileged is None:
            return "Negative predictive value (NPV = TN / (TN + FN)): {}".format(
                self.metric.negative_predictive_value(privileged=privileged))
        return "Negative predictive value on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.negative_predictive_value(privileged=privileged))

    def num_false_negatives(self, privileged=None):
        if privileged is None:
            return "Number of false negative instances (FN): {}".format(
                self.metric.num_false_negatives(privileged=privileged))
        return "Number of {} false negative instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.num_false_negatives(privileged=privileged))

    def num_false_positives(self, privileged=None):
        if privileged is None:
            return "Number of false positive instances (FP): {}".format(
                self.metric.num_false_positives(privileged=privileged))
        return "Number of {} false positive instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.num_false_positives(privileged=privileged))

    def num_instances(self, privileged=None):
        if privileged is None:
            return "Number of instances: {}".format(
                self.metric.num_instances(privileged=privileged))
        return "Number of {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.num_instances(privileged=privileged))

    def num_negatives(self, privileged=None):
        if privileged is None:
            return "Number of negative-outcome instances: {}".format(
                self.metric.num_negatives(privileged=privileged))
        return "Number of {} negative-outcome instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.num_negatives(privileged=privileged))

    def num_positives(self, privileged=None):
        if privileged is None:
            return "Number of positive-outcome instances: {}".format(
                self.metric.num_positives(privileged=privileged))
        return "Number of {} positive-outcome instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.num_positives(privileged=privileged))

    def num_pred_negatives(self, privileged=None):
        if privileged is None:
            return "Number of negative-outcome instances predicted: {}".format(
                self.metric.num_pred_negatives(privileged=privileged))
        return "Number of {} negative-outcome instances predicted: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.num_pred_negatives(privileged=privileged))

    def num_pred_positives(self, privileged=None):
        if privileged is None:
            return "Number of positive-outcome instances predicted: {}".format(
                self.metric.num_pred_positives(privileged=privileged))
        return "Number of {} positive-outcome instances predicted: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.num_pred_positives(privileged=privileged))

    def num_true_negatives(self, privileged=None):
        if privileged is None:
            return "Number of true negative instances (TN): {}".format(
                self.metric.num_true_negatives(privileged=privileged))
        return "Number of {} true negative instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.num_true_negatives(privileged=privileged))

    def num_true_positives(self, privileged=None):
        if privileged is None:
            return "Number of true positive instances (TP): {}".format(
                self.metric.num_true_positives(privileged=privileged))
        return "Number of {} true positive instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.num_true_positives(privileged=privileged))

    def positive_predictive_value(self, privileged=None):
        if privileged is None:
            return "Positive predictive value (PPV, precision = TP / (TP + FP)): {}".format(
                self.metric.positive_predictive_value(privileged=privileged))
        return "Positive predictive value on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.positive_predictive_value(privileged=privileged))

    def statistical_parity_difference(self):
        return ("Statistical parity difference (probability of favorable "
                "outcome for unprivileged instances - probability of favorable "
                "outcome for privileged instances): {}".format(
                    self.metric.statistical_parity_difference()))

    def theil_index(self):
        return "Theil index (generalized entropy index with alpha = 1): {}".format(
            self.metric.theil_index())

    def true_negative_rate(self, privileged=None):
        if privileged is None:
            return "True negative rate (TNR, specificity = TN / (FP + TN)): {}".format(
                self.metric.true_negative_rate(privileged=privileged))
        return "True negative rate on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.true_negative_rate(privileged=privileged))

    def true_positive_rate(self, privileged=None):
        if privileged is None:
            return "True positive rate (TPR, recall, sensitivity = TP / (TP + FN)): {}".format(
                self.metric.true_positive_rate(privileged=privileged))
        return "True positive rate on {} instances: {}".format(
            'privileged' if privileged else 'unprivileged',
            self.metric.true_positive_rate(privileged=privileged))

    def true_positive_rate_difference(self):
        return ("True positive rate difference (true positive rate on "
                "unprivileged instances - true positive rate on privileged "
                "instances): {}".format(
                    self.metric.true_positive_rate_difference()))

    # ============================== ALIASES ===================================
    def equal_opportunity_difference(self):
        return self.true_positive_rate_difference()

    def power(self, privileged=None):
        return self.num_true_positives(privileged=privileged)

    def precision(self, privileged=None):
        return self.positive_predictive_value(privileged=privileged)

    def recall(self, privileged=None):
        return self.true_positive_rate(privileged=privileged)

    def sensitivity(self, privileged=None):
        return self.true_positive_rate(privileged=privileged)

    def specificity(self, privileged=None):
        return self.true_negative_rate(privileged=privileged)