Exact Match¶
Module Interface¶
MultilabelExactMatch¶
- class torchmetrics.classification.MultilabelExactMatch(num_labels, threshold=0.5, multidim_average='global', ignore_index=None, validate_args=True, **kwargs)[source]
Computes Exact match (also known as subset accuracy) for multilabel tasks. Exact Match is a stricter version of accuracy where all labels have to match exactly for the sample to be correctly classified.
Accepts the following input tensors:
preds
(int or float tensor):(N, C, ...)
. If preds is a floating point tensor with values outside [0,1] range we consider the input to be logits and will auto apply sigmoid per element. Addtionally, we convert to int tensor with thresholding using the value inthreshold
.target
(int tensor):(N, C, ...)
The influence of the additional dimension
...
(if present) will be determined by the multidim_average argument.- Parameters
threshold¶ (
float
) – Threshold for transforming probability to binary (0,1) predictionsmultidim_average¶ (
Literal
[‘global’, ‘samplewise’]) –Defines how additionally dimensions
...
should be handled. Should be one of the following:global
: Additional dimensions are flatted along the batch dimensionsamplewise
: Statistic will be calculated independently for each sample on theN
axis. The statistics in this case are calculated over the additional dimensions.
ignore_index¶ (
Optional
[int
]) – Specifies a target value that is ignored and does not contribute to the metric calculationvalidate_args¶ (
bool
) – bool indicating if input arguments and tensors should be validated for correctness. Set toFalse
for faster computations.
- Returns
If
multidim_average
is set toglobal
:If
average='micro'/'macro'/'weighted'
, the output will be a scalar tensorIf
average=None/'none'
, the shape will be(C,)
If
multidim_average
is set tosamplewise
:If
average='micro'/'macro'/'weighted'
, the shape will be(N,)
If
average=None/'none'
, the shape will be(N, C)
- Return type
The returned shape depends on the
average
andmultidim_average
arguments
- Example (preds is int tensor):
>>> from torchmetrics.classification import MultilabelExactMatch >>> target = torch.tensor([[0, 1, 0], [1, 0, 1]]) >>> preds = torch.tensor([[0, 0, 1], [1, 0, 1]]) >>> metric = MultilabelExactMatch(num_labels=3) >>> metric(preds, target) tensor(0.5000)
- Example (preds is float tensor):
>>> from torchmetrics.classification import MultilabelExactMatch >>> target = torch.tensor([[0, 1, 0], [1, 0, 1]]) >>> preds = torch.tensor([[0.11, 0.22, 0.84], [0.73, 0.33, 0.92]]) >>> metric = MultilabelExactMatch(num_labels=3) >>> metric(preds, target) tensor(0.5000)
- Example (multidim tensors):
>>> from torchmetrics.classification import MultilabelExactMatch >>> target = torch.tensor([[[0, 1], [1, 0], [0, 1]], [[1, 1], [0, 0], [1, 0]]]) >>> preds = torch.tensor( ... [ ... [[0.59, 0.91], [0.91, 0.99], [0.63, 0.04]], ... [[0.38, 0.04], [0.86, 0.780], [0.45, 0.37]], ... ] ... ) >>> metric = MultilabelExactMatch(num_labels=3, multidim_average='samplewise') >>> metric(preds, target) tensor([0., 0.])
Initializes internal Module state, shared by both nn.Module and ScriptModule.
- compute()[source]
Override this method to compute the final metric value from state variables synchronized across the distributed backend.
- Return type
Functional Interface¶
multilabel_exact_match¶
- torchmetrics.functional.classification.multilabel_exact_match(preds, target, num_labels, threshold=0.5, multidim_average='global', ignore_index=None, validate_args=True)[source]
Computes Exact match (also known as subset accuracy) for multilabel tasks. Exact Match is a stricter version of accuracy where all labels have to match exactly for the sample to be correctly classified.
Accepts the following input tensors:
preds
(int or float tensor):(N, C, ...)
. If preds is a floating point tensor with values outside [0,1] range we consider the input to be logits and will auto apply sigmoid per element. Addtionally, we convert to int tensor with thresholding using the value inthreshold
.target
(int tensor):(N, C, ...)
The influence of the additional dimension
...
(if present) will be determined by the multidim_average argument.- Parameters
threshold¶ (
float
) – Threshold for transforming probability to binary (0,1) predictionsmultidim_average¶ (
Literal
[‘global’, ‘samplewise’]) –Defines how additionally dimensions
...
should be handled. Should be one of the following:global
: Additional dimensions are flatted along the batch dimensionsamplewise
: Statistic will be calculated independently for each sample on theN
axis. The statistics in this case are calculated over the additional dimensions.
ignore_index¶ (
Optional
[int
]) – Specifies a target value that is ignored and does not contribute to the metric calculationvalidate_args¶ (
bool
) – bool indicating if input arguments and tensors should be validated for correctness. Set toFalse
for faster computations.
- Returns
If
multidim_average
is set toglobal
:If
average='micro'/'macro'/'weighted'
, the output will be a scalar tensorIf
average=None/'none'
, the shape will be(C,)
If
multidim_average
is set tosamplewise
:If
average='micro'/'macro'/'weighted'
, the shape will be(N,)
If
average=None/'none'
, the shape will be(N, C)
- Return type
The returned shape depends on the
average
andmultidim_average
arguments
- Example (preds is int tensor):
>>> from torchmetrics.functional.classification import multilabel_exact_match >>> target = torch.tensor([[0, 1, 0], [1, 0, 1]]) >>> preds = torch.tensor([[0, 0, 1], [1, 0, 1]]) >>> multilabel_exact_match(preds, target, num_labels=3) tensor(0.5000)
- Example (preds is float tensor):
>>> from torchmetrics.functional.classification import multilabel_exact_match >>> target = torch.tensor([[0, 1, 0], [1, 0, 1]]) >>> preds = torch.tensor([[0.11, 0.22, 0.84], [0.73, 0.33, 0.92]]) >>> multilabel_exact_match(preds, target, num_labels=3) tensor(0.5000)
- Example (multidim tensors):
>>> from torchmetrics.functional.classification import multilabel_exact_match >>> target = torch.tensor([[[0, 1], [1, 0], [0, 1]], [[1, 1], [0, 0], [1, 0]]]) >>> preds = torch.tensor( ... [ ... [[0.59, 0.91], [0.91, 0.99], [0.63, 0.04]], ... [[0.38, 0.04], [0.86, 0.780], [0.45, 0.37]], ... ] ... ) >>> multilabel_exact_match(preds, target, num_labels=3, multidim_average='samplewise') tensor([0., 0.])