Given a QR factorization of a real or complex matrix A = Q*R, Q unitary and R upper trapezoidal, return the QR factorization of [A(:,1:j-1) x A(:,j:n)], where u is a column vector to be inserted into A (if orient is
"col"
), or the QR factorization of [A(1:j-1,:);x;A(:,j:n)], where x is a row vector to be inserted into A (if orient is"row"
).The default value of orient is
"col"
.If orient is
"col"
and the matrix Q is not square, then what gets inserted is the projection of u onto the space spanned by columns of Q, i.e. Q*Q'*u.If orient is
"row"
, Q must be square.