9b664bd7cd8dbb9657626166ba61887ed06774d7,gpytorch/utils/toeplitz.py,,index_coef_to_sparse,#Any#Any#Any#,6

Before Change

    num_target_points, num_coefficients = value_matrix.size()
    index_list = [[], []]
    value_list = []
    for i in range(num_target_points):
        for j in range(num_coefficients):
            if value_matrix[i, j] == 0:
                continue
            index_list[0].append(i)
            index_list[1].append(index_matrix[i, j])
            value_list.append(value_matrix[i, j])

    index_tensor = torch.LongTensor(index_list)
    value_tensor = torch.FloatTensor(value_list)
    res = torch.sparse.FloatTensor(index_tensor, value_tensor, torch.Size([num_target_points, row_length]))
    return res

After Change

    num_target_points, num_coefficients = value_matrix.size()

    row_tensor = torch.arange(0, num_target_points).unsqueeze(1)
    row_tensor = row_tensor.repeat(1, num_coefficients).type_as(index_matrix)
    index_tensor = torch.cat([row_tensor.view(1, -1), index_matrix.view(1, -1)], 0)
    value_tensor = value_matrix.view(-1)

    nonzero_indices = value_tensor.nonzero()
    if nonzero_indices.storage():
        nonzero_indices.squeeze_()
        index_tensor = index_tensor.index_select(1, nonzero_indices)
        value_tensor = value_tensor.index_select(0, nonzero_indices)
    else:
        index_tensor = index_tensor.resize_(2, 1).zero_()
        value_tensor = value_tensor.resize_(1).zero_()

Instances