torch.Tensor.to_sparse_csc#

Tensor.to_sparse_csc()→Tensor#

Convert a tensor to compressed column storage (CSC) format. Exceptfor strided tensors, only works with 2D tensors. If theselfis strided, then the number of dense dimensions could be specified,and a hybrid CSC tensor will be created, withdense_dim densedimensions andself.dim() - 2 - dense_dim batch dimension.

Parameters

dense_dim (int,optional) – Number of dense dimensions of theresulting CSC tensor. This argument should be used only ifself is a strided tensor, and must be a value between 0and dimension ofself tensor minus two.

Example:

>>>dense=torch.randn(5,5)>>>sparse=dense.to_sparse_csc()>>>sparse._nnz()25>>>dense=torch.zeros(3,3,1,1)>>>dense[0,0]=dense[1,2]=dense[2,1]=1>>>dense.to_sparse_csc(dense_dim=2)tensor(ccol_indices=tensor([0, 1, 2, 3]),       row_indices=tensor([0, 2, 1]),       values=tensor([[[1.]],                      [[1.]],                      [[1.]]]), size=(3, 3, 1, 1), nnz=3,       layout=torch.sparse_csc)