DiceCoefficient

ignite.metrics.DiceCoefficient(cm, ignore_index=None)

Calculates Dice Coefficient for a given ConfusionMatrix metric.

Parameters

• cm (ConfusionMatrix) – instance of confusion matrix metric

• ignore_index (Optional[int]) – index to ignore, e.g. background index

Return type

MetricsLambda

Examples

cm = ConfusionMatrix(num_classes=3)
metric = DiceCoefficient(cm, ignore_index=0)
metric.attach(default_evaluator, 'dice')
y_true = torch.Tensor([0, 1, 0, 1, 2]).long()
y_pred = torch.Tensor([
    [0.0, 1.0, 0.0],
    [0.0, 1.0, 0.0],
    [1.0, 0.0, 0.0],
    [0.0, 1.0, 0.0],
    [0.0, 1.0, 0.0],
])
state = default_evaluator.run([[y_pred, y_true]])
print(state.metrics['dice'])

tensor([0.6667, 0.0000], dtype=torch.float64)