This function is not yet fully documented. This is a transcript of the text-formatted help.
bbdbltoeplitz Create an operator for a doubly Toeplitz matrix A matrix, BB, is doubly Toeplitz if it can be written in the form: BB=[ U0, U1, U2, ... L1, U0, U1, ... L2, L1, L2, ... ............... ] where U0,U1,... and L1,L2,... are Toeplitz matrices. In words, a doubly Toeplitz matrix is a block Toeplitz matrix with Toeplitz blocks. Is is also known as "Toeplitz-Block Toeplitz". Syntax: BB=bbdbltoeplitz(RU) BB=bbdbltoeplitz(CU,RU) BB=bbdbltoeplitz(CU,RU,CL,RL) BB=bbdbltoeplitz(CU,RU,[],[]) RU contains the first rows in U0,U1,..., while CU contain the columns: CU=[U0(:,1) , U1(:,1) , U2(:,1) , ...] RU=[U0(1,:) ; U1(1,:) ; U2(1,:) ; ...] If CU is unspecified, the blocks are assumed to be Hermitian: U0=U0', U1=U1', etc. CL and RL contain the first columns and rows of L1,L2,...: CL=[L1(:,1) , L2(:,1) , ...] RL=[L1(1,:) ; L2(1,:) ; ...] If CL and RL are unspecified, BB will be block-Hermitian: L1=U1', L2=U2', etc. If CL and RL are empty matrices, BB consist of a single block row: BB=[U0, U1, ... ] NOTE: The first element in the column and row in each block must be the same. See also bbtoeplitz, .