mmclassification/mmcls/models/losses/accuracy.py

144 lines
4.7 KiB
Python

# Copyright (c) OpenMMLab. All rights reserved.
from numbers import Number
import numpy as np
import torch
import torch.nn as nn
def accuracy_numpy(pred, target, topk=(1, ), thrs=0.):
if isinstance(thrs, Number):
thrs = (thrs, )
res_single = True
elif isinstance(thrs, tuple):
res_single = False
else:
raise TypeError(
f'thrs should be a number or tuple, but got {type(thrs)}.')
res = []
maxk = max(topk)
num = pred.shape[0]
static_inds = np.indices((num, maxk))[0]
pred_label = pred.argpartition(-maxk, axis=1)[:, -maxk:]
pred_score = pred[static_inds, pred_label]
sort_inds = np.argsort(pred_score, axis=1)[:, ::-1]
pred_label = pred_label[static_inds, sort_inds]
pred_score = pred_score[static_inds, sort_inds]
for k in topk:
correct_k = pred_label[:, :k] == target.reshape(-1, 1)
res_thr = []
for thr in thrs:
# Only prediction values larger than thr are counted as correct
_correct_k = correct_k & (pred_score[:, :k] > thr)
_correct_k = np.logical_or.reduce(_correct_k, axis=1)
res_thr.append((_correct_k.sum() * 100. / num))
if res_single:
res.append(res_thr[0])
else:
res.append(res_thr)
return res
def accuracy_torch(pred, target, topk=(1, ), thrs=0.):
if isinstance(thrs, Number):
thrs = (thrs, )
res_single = True
elif isinstance(thrs, tuple):
res_single = False
else:
raise TypeError(
f'thrs should be a number or tuple, but got {type(thrs)}.')
res = []
maxk = max(topk)
num = pred.size(0)
pred = pred.float()
pred_score, pred_label = pred.topk(maxk, dim=1)
pred_label = pred_label.t()
correct = pred_label.eq(target.view(1, -1).expand_as(pred_label))
for k in topk:
res_thr = []
for thr in thrs:
# Only prediction values larger than thr are counted as correct
_correct = correct & (pred_score.t() > thr)
correct_k = _correct[:k].reshape(-1).float().sum(0, keepdim=True)
res_thr.append((correct_k.mul_(100. / num)))
if res_single:
res.append(res_thr[0])
else:
res.append(res_thr)
return res
def accuracy(pred, target, topk=1, thrs=0.):
"""Calculate accuracy according to the prediction and target.
Args:
pred (torch.Tensor | np.array): The model prediction.
target (torch.Tensor | np.array): The target of each prediction
topk (int | tuple[int]): If the predictions in ``topk``
matches the target, the predictions will be regarded as
correct ones. Defaults to 1.
thrs (Number | tuple[Number], optional): Predictions with scores under
the thresholds are considered negative. Default to 0.
Returns:
torch.Tensor | list[torch.Tensor] | list[list[torch.Tensor]]: Accuracy
- torch.Tensor: If both ``topk`` and ``thrs`` is a single value.
- list[torch.Tensor]: If one of ``topk`` or ``thrs`` is a tuple.
- list[list[torch.Tensor]]: If both ``topk`` and ``thrs`` is a \
tuple. And the first dim is ``topk``, the second dim is ``thrs``.
"""
assert isinstance(topk, (int, tuple))
if isinstance(topk, int):
topk = (topk, )
return_single = True
else:
return_single = False
assert isinstance(pred, (torch.Tensor, np.ndarray)), \
f'The pred should be torch.Tensor or np.ndarray ' \
f'instead of {type(pred)}.'
assert isinstance(target, (torch.Tensor, np.ndarray)), \
f'The target should be torch.Tensor or np.ndarray ' \
f'instead of {type(target)}.'
# torch version is faster in most situations.
to_tensor = (lambda x: torch.from_numpy(x)
if isinstance(x, np.ndarray) else x)
pred = to_tensor(pred)
target = to_tensor(target)
res = accuracy_torch(pred, target, topk, thrs)
return res[0] if return_single else res
class Accuracy(nn.Module):
def __init__(self, topk=(1, )):
"""Module to calculate the accuracy.
Args:
topk (tuple): The criterion used to calculate the
accuracy. Defaults to (1,).
"""
super().__init__()
self.topk = topk
def forward(self, pred, target):
"""Forward function to calculate accuracy.
Args:
pred (torch.Tensor): Prediction of models.
target (torch.Tensor): Target for each prediction.
Returns:
list[torch.Tensor]: The accuracies under different topk criterions.
"""
return accuracy(pred, target, self.topk)