torch.bincount — PyTorch 2.7 documentation (original) (raw)

torch.bincount(input, weights=None, minlength=0) → Tensor¶

Count the frequency of each value in an array of non-negative ints.

The number of bins (size 1) is one larger than the largest value ininput unless input is empty, in which case the result is a tensor of size 0. If minlength is specified, the number of bins is at leastminlength and if input is empty, then the result is tensor of sizeminlength filled with zeros. If n is the value at position i,out[n] += weights[i] if weights is specified elseout[n] += 1.

Note

This operation may produce nondeterministic gradients when given tensors on a CUDA device. See Reproducibility for more information.

Parameters

• input (Tensor) – 1-d int tensor
• weights (Tensor) – optional, weight for each value in the input tensor. Should be of same size as input tensor.
• minlength (int) – optional, minimum number of bins. Should be non-negative.

Returns

a tensor of shape Size([max(input) + 1]) ifinput is non-empty, else Size(0)

Return type

output (Tensor)

Example:

input = torch.randint(0, 8, (5,), dtype=torch.int64) weights = torch.linspace(0, 1, steps=5) input, weights (tensor([4, 3, 6, 3, 4]), tensor([ 0.0000, 0.2500, 0.5000, 0.7500, 1.0000])

torch.bincount(input) tensor([0, 0, 0, 2, 2, 0, 1])

input.bincount(weights) tensor([0.0000, 0.0000, 0.0000, 1.0000, 1.0000, 0.0000, 0.5000])