lftdata
Decompose uncertain objects into fixed certain and normalized uncertain parts
Syntax
[M,Delta] = lftdata(A); [M,Delta] = lftdata(A,List); [M,Delta,Blkstruct] = lftdata(A); [M,Delta,Blkstruct,Normunc] = lftdata(A);
Description
lftdata
decomposes an uncertain object into a
fixed certain part and a normalized uncertain part. lftdata
can also
partially decompose an uncertain object into an uncertain part and a normalized uncertain
part. Uncertain objects (umat
, ufrd
, uss
)
are represented as certain (i.e., not-uncertain) objects in feedback with block-diagonal
concatenations of uncertain elements.
[M,Delta] = lftdata(A)
separates the uncertain
object A
into a certain object M
and a normalized
uncertain matrix Delta
such that A
is equal to
lft(Delta,M)
, as shown below.
If A
is a umat
, then M
will be
double
; if A
is a uss
, then
M
will be ss
; if A
is a
ufrd
, then M
will be frd
. In all
cases, Delta
is a umat
.
[M,Delta] = lftdata(A,List)
separates the
uncertain object A
into an uncertain object M
, in
feedback with a normalized uncertain matrix Delta
. List
is a cell (or char) array of names of uncertain elements of A
that make up
Delta
. All other uncertainty in A
remains in
M
.
lftdata(A,fieldnames(A.Uncertainty))
is the same as
lftdata(A)
.
[M,DELTA,BLKSTRUCT] = lftdata(A)
returns an
N-by-1 structure array BLKSTRUCT
, where
BLKSTRUCT(i)
describes the i
-th normalized uncertain
element. This uncertainty description can be passed directly to the low-level structured
singular value analysis function mussv
.
[M,DELTA,BLKSTRUCT,NORMUNC] = lftdata(A)
returns
the cell array NORMUNC
of normalized uncertain elements. Each normalized
element has 'Normalized'
appended to its original name to avoid confusion.
Note that lft(blkdiag(NORMUNC{:}),M)
is equivalent to A
.
The normalizations for each type of uncertain element are described in Decomposing Uncertain Objects.
Examples
Version History
Introduced before R2006a