sum of subspaces
[X,dim,dima]=spanplus(A,B[,tol])
two real or complex matrices with equal number of rows
orthogonal or unitary square matrix
integers, dimension of subspaces
nonnegative real number
computes a basis X such that:
the first dima
columns of X
span Range(A
)
and the following (dim-dima
) columns make a basis of A+B
relative to A
.
The dim
first columns of X
make a basis for A+B
.
One has the following canonical form for [A,B]
:
tol
is an optional argument (see function code).