Computes average precision@k of predictions with respect to sparse labels.
tf.metrics.average_precision_at_k( labels, predictions, k, weights=None, metrics_collections=None, updates_collections=None, name=None )
average_precision_at_k
creates two local variables, average_precision_at_<k>/total
and average_precision_at_<k>/max
, that are used to compute the frequency. This frequency is ultimately returned as average_precision_at_<k>
: an idempotent operation that simply divides average_precision_at_<k>/total
by average_precision_at_<k>/max
.
For estimation of the metric over a stream of data, the function creates an update_op
operation that updates these variables and returns the precision_at_<k>
. Internally, a top_k
operation computes a Tensor
indicating the top k
predictions
. Set operations applied to top_k
and labels
calculate the true positives and false positives weighted by weights
. Then update_op
increments true_positive_at_<k>
and false_positive_at_<k>
using these values.
If weights
is None
, weights default to 1. Use weights of 0 to mask values.
Args | |
---|---|
labels | int64 Tensor or SparseTensor with shape [D1, ... DN, num_labels] or [D1, ... DN], where the latter implies num_labels=1. N >= 1 and num_labels is the number of target classes for the associated prediction. Commonly, N=1 and labels has shape [batch_size, num_labels]. [D1, ... DN] must match predictions . Values should be in range [0, num_classes), where num_classes is the last dimension of predictions . Values outside this range are ignored. |
predictions | Float Tensor with shape [D1, ... DN, num_classes] where N >= 1. Commonly, N=1 and predictions has shape [batch size, num_classes]. The final dimension contains the logit values for each class. [D1, ... DN] must match labels . |
k | Integer, k for @k metric. This will calculate an average precision for range [1,k] , as documented above. |
weights | Tensor whose rank is either 0, or n-1, where n is the rank of labels . If the latter, it must be broadcastable to labels (i.e., all dimensions must be either 1 , or the same as the corresponding labels dimension). |
metrics_collections | An optional list of collections that values should be added to. |
updates_collections | An optional list of collections that updates should be added to. |
name | Name of new update operation, and namespace for other dependent ops. |
Returns | |
---|---|
mean_average_precision | Scalar float64 Tensor with the mean average precision values. |
update | Operation that increments variables appropriately, and whose value matches metric . |
Raises | |
---|---|
ValueError | if k is invalid. |
RuntimeError | If eager execution is enabled. |
© 2020 The TensorFlow Authors. All rights reserved.
Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/versions/r1.15/api_docs/python/tf/metrics/average_precision_at_k