Scilab Home page | Wiki | Bug tracker | Forge | Mailing list archives | ATOMS | File exchange
Please login or create an account
Change language to: English - Português - 日本語 - Русский

Please note that the recommended version of Scilab is 6.0.1. This page might be outdated.
See the recommended documentation of this function

Aide de Scilab >> Algèbre Lineaire > Subspaces > spaninter


subspace intersection

Calling Sequence

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


A, B

two real or complex matrices with equal number of rows


orthogonal or unitary square matrix


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


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).


A=rand(5,3)*rand(3,4);     // A is 5 x 4, rank=3
X1=X(:,1:dim);    //The intersection
svd(A),svd([X1,A])   // X1 in span(A)
svd(B),svd([B,X1])   // X1 in span(B)

See Also

  • spanplus — sum of subspaces
  • spantwo — sum and intersection of subspaces
Scilab Enterprises
Copyright (c) 2011-2017 (Scilab Enterprises)
Copyright (c) 1989-2012 (INRIA)
Copyright (c) 1989-2007 (ENPC)
with contributors
Last updated:
Thu Oct 02 13:54:30 CEST 2014