Recall¶

class paddle.fluid.metrics.Recall(name=None)[source]

Recall (also known as sensitivity) is the fraction of relevant instances that have been retrieved over the total amount of relevant instances

Refer to: https://en.wikipedia.org/wiki/Precision_and_recall

Noted that this class mangages the recall score only for binary classification task.

Parameters

name (str, optional) – Metric name. For details, please refer to Name. Default is None.

Examples

import paddle.fluid as fluid
import numpy as np

metric = fluid.metrics.Recall()

# generate the preds and labels

preds = [[0.1], [0.7], [0.8], [0.9], [0.2],
         [0.2], [0.3], [0.5], [0.8], [0.6]]

labels = [[0], [1], [1], [1], [1],
          [0], [0], [0], [0], [0]]

preds = np.array(preds)
labels = np.array(labels)

metric.update(preds=preds, labels=labels)
numpy_recall = metric.eval()

print("expect recall: %.2f and got %.2f" % ( 3.0 / 4.0, numpy_recall))

update(preds, labels)

Update the recall based on the current mini-batch prediction results.

Parameters

• preds (numpy.array) – prediction results of current mini-batch, the output of two-class sigmoid function. Shape: [batch_size, 1]. Dtype: ‘float64’ or ‘float32’.

• labels (numpy.array) – ground truth (labels) of current mini-batch, the shape should keep the same as preds. Shape: [batch_size, 1], Dtype: ‘int32’ or ‘int64’.

eval()

Calculate the final recall.

Returns

results of the calculated Recall. Scalar output with float dtype.

Return type

float

get_config()

Get the metric and current states. The states are the members who do not has “_” prefix.

Parameters

None –

Returns

a python dict, which costains the inner states of the metric instance

Return types:

a python dict

reset()

reset function empties the evaluation memory for previous mini-batches.

Parameters

None –

Returns

None

Return types:

None