qr(G)

NAME
qr - QR decomposition

CALLING SEQUENCE
[Q,R]=qr(X)
[Q,R,E]=qr(X)
[Q,R,rk,E]=qr(X,tol)

PARAMETERS

X   : real or complex matrix

tol : nonnegative real number

Q   : square orthogonal or unitary matrix

R   : matrix with same dimensions as X

E   : permutation matrix

rk  : integer (QR-rank of X*E)

DESCRIPTION
produces an upper triangular matrix R of
the same dimension as X and a unitary matrix Q so that
X = Q*R.

produces a (column) permutation matrix E,
an upper triangular R with decreasing diagonal elements and
a unitary Q so that X*E = Q*R.

returns rk = rank estimate of X i.e.
rk is the number of diagonal elements in R which are
larger than tol.

SEE ALSO
rank, svd, rowcomp, colcomp.