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

torch.cumprod(input, dim, *, dtype=None, out=None) → Tensor¶

Returns the cumulative product of elements of input in the dimensiondim.

For example, if input is a vector of size N, the result will also be a vector of size N, with elements.

yi=x1×x2×x3×⋯×xiy_i = x_1 \times x_2\times x_3\times \dots \times x_i

Parameters

• input (Tensor) – the input tensor.
• dim (int) – the dimension to do the operation over

Keyword Arguments

• dtype (torch.dtype, optional) – the desired data type of returned tensor. If specified, the input tensor is casted to dtype before the operation is performed. This is useful for preventing data type overflows. Default: None.
• out (Tensor, optional) – the output tensor.

Example:

a = torch.randn(10) a tensor([ 0.6001, 0.2069, -0.1919, 0.9792, 0.6727, 1.0062, 0.4126, -0.2129, -0.4206, 0.1968]) torch.cumprod(a, dim=0) tensor([ 0.6001, 0.1241, -0.0238, -0.0233, -0.0157, -0.0158, -0.0065, 0.0014, -0.0006, -0.0001])

a[5] = 0.0 torch.cumprod(a, dim=0) tensor([ 0.6001, 0.1241, -0.0238, -0.0233, -0.0157, -0.0000, -0.0000, 0.0000, -0.0000, -0.0000])