spaninter(1)

NAME
spaninter - subspace intersection

CALLING SEQUENCE
[X,dim]=spaninter(A,B [,tol])

PARAMETERS

A, B
    : two real or complex matrices with equal number of rows

X   : orthogonal or unitary square matrix

dim : integer, dimension of subspace range(A) inter range(B)

DESCRIPTION
computes the intersection of range(A) and range(B).

The first dim columns of X span this intersection i.e.
X(:,1:dim) is an orthogonal basis for
range(A) inter range(B)

In the X basis A and B are respectively represented by:

X'*A and X'*B.

tol is a threshold (sqrt(%eps) is the default value).

SEE ALSO
spanplus, spantwo

AUTHOR
F. D.