Pretty printing of tensor

[tgkolda]

I would like to propose prettier printing of tensors. Here is an example of the code that I would suggest for a dense tensor. Ideally, this would be the default print. It allows the user to indicate the formatting and the name. It always prints the frontal slices, regardless of the underlying storage format.

def pretty_print_tensor(X, fmt="10.4f", name="Slice"):
    if not isinstance(X, ttb.tensor):
        raise ValueError("Input must be a pyttb tensor")

    # Get the shape of the tensor
    shape = X.shape

    if name == "Slice":
        print("Tensor is of shape "+ " x ".join(map(str, shape)))
    else:
        print(f"{name} is a tensor of shape " + " x ".join(map(str, shape)))


    # Iterate over all possible slices (in Fortran order)
    for index in np.ndindex(shape[2:][::-1]): # Skip the first two dimensions and reverse the order
        index = index[::-1] # Reverse the order back to the original
        # Construct the slice indices
        slice_indices = (slice(None), slice(None)) + index
        slice_data = X[slice_indices]
        print(f"{name}(:, :, {', '.join(map(str, index))}) =")
        array = slice_data.data
        for row in array:
            print(" ".join(f"{val:{fmt}}" for val in row))

[ntjohnson1]

This is a duplicate of #350 correct?