opBlockDiag Operator-diagonal operator.
B = opBlockDiag(OP1, OP2,...,OPN,OVERLAP) creates a compound block
operator with the input operators OP1, OP2,... on the diagonal of
B, e.g., B = DIAG([OP1 OP2 ... OPN]). When OVERLAP is a positive
integer the blocks will be offset OVERLAP rows relative to the
previous operator, when OVERLAP is negative the operators are
offset by the absolute value of OVERLAP in columns. Note that
choosing OVERLAP larger than the operator size may cause the
matrix to become block antidiagonal.
B = opBlockDiag(WEIGHT,OP1,...,OPN,OVERLAP) additionally
weights each block by the elements of the vector WEIGHT. If
only a single operator is given it is replicated as many times
as there are weights.
B = opBlockDiag(N,OP,OVERLAP) similar as above with WEIGHT
equal to ones(N,1). This will cause operator OP to be repeated
N times.