in slowfast/utils/ava_evaluation/metrics.py [0:0]
def compute_average_precision(precision, recall):
"""Compute Average Precision according to the definition in VOCdevkit.
Precision is modified to ensure that it does not decrease as recall
decrease.
Args:
precision: A float [N, 1] numpy array of precisions
recall: A float [N, 1] numpy array of recalls
Raises:
ValueError: if the input is not of the correct format
Returns:
average_precison: The area under the precision recall curve. NaN if
precision and recall are None.
"""
if precision is None:
if recall is not None:
raise ValueError("If precision is None, recall must also be None")
return np.NAN
if not isinstance(precision, np.ndarray) or not isinstance(
recall, np.ndarray
):
raise ValueError("precision and recall must be numpy array")
if precision.dtype != np.float or recall.dtype != np.float:
raise ValueError("input must be float numpy array.")
if len(precision) != len(recall):
raise ValueError("precision and recall must be of the same size.")
if not precision.size:
return 0.0
if np.amin(precision) < 0 or np.amax(precision) > 1:
raise ValueError("Precision must be in the range of [0, 1].")
if np.amin(recall) < 0 or np.amax(recall) > 1:
raise ValueError("recall must be in the range of [0, 1].")
if not all(recall[i] <= recall[i + 1] for i in range(len(recall) - 1)):
raise ValueError("recall must be a non-decreasing array")
recall = np.concatenate([[0], recall, [1]])
precision = np.concatenate([[0], precision, [0]])
# Preprocess precision to be a non-decreasing array
for i in range(len(precision) - 2, -1, -1):
precision[i] = np.maximum(precision[i], precision[i + 1])
indices = np.where(recall[1:] != recall[:-1])[0] + 1
average_precision = np.sum(
(recall[indices] - recall[indices - 1]) * precision[indices]
)
return average_precision