## bbblktoep1s

This function is not yet fully documented. This is a transcript of
the text-formatted help.

bbblktoep1s Create sparse/small block-Toeplitz type-1 operator.
A block-Toeplitz operator of type-1 is a matrix which can be written
on the form:
BB=[U0, U1, U2, ...
L1, U0, U1, ...
L2, L1, U0, ...
When many blocks are zeros, or there is limited number of blocks,
Fourier methods may be inefficient compared to direct evaluation.
In this case bbblktoep1s is appropiate.
BB=bbblktoep1s(U,L) constructs the operator, where U and L are cell
arrays containing the U- and L-blocks:
U={U0, U1, U2, ...}
L={L1, L2, L3, ...}
A block can be a black-box operator, a Matlab matrix or an empty
matrix. An empty matrix is equivalent to a zero block.
ALGORITHM: products are evaluated directly. However, the evaluation
is blocked, and is rich in matrix-matrix multiplications, which
makes it reasonably efficient.
See also bbtoeplitz, .

bbaddbbclear