fips.Operator.__getitem__

Operator.__getitem__(key)

Return the block of one row block and one column block.

Parameters:

key (tuple[str, str]) – The names of the row block and the column block.

Returns:

The block, on spaces of those single blocks, labeled as each block was given. A diagonal block of a Covariance is a Covariance, and keeps the form (Kronecker factors stay factors).

Return type:

Operator

Raises:

KeyError – If either space has no block of that name.