A numerical algorithm for computing the restricted singular value decomposition of matrix triplets

A numerical algorithm for computing the restricted singular value decomposition of matrix triplets

es Submittedby Richard A. Brualdi An algoriam is developed for computing the restricted singular value decomposipIets. It consists of three stages: ...

2MB Sizes 10 Downloads 123 Views

es

Submittedby Richard A. Brualdi

An algoriam is developed for computing the restricted singular value decomposipIets. It consists of three stages: we first show that SVD) of general matrix orthogonal transformations can constructed to extract a regular triplet from a given essing the regular tiplet, we reduce general matrix triplet; after p to computing o1~: ordinary singular value decomposition of a product of matrices having the same number of dimensions; then we apply the tliantz technique to this matrix product. Other structural indices of the obtained by computing the ranks of certain submatrices. NumericaI examples are provided to illustrate the accuracy of the algorithm.

1.

INT

N

singular vahe &mnnposition ( the ordinary matrices [s]. The

singular

*Part of the work was done while

the author was a visitor at

1 is

minimization wi

an efficient met

to preprocess the regular triplet, which will e dimension; in Section 5,

rAB = ran

rA,

= r

c = ran

?

owing nomenclature is the ordinary s

the restricted sin n this paper only the case case of complex matrices are s

s is discussed; extensions to

n this section we brie the concept of more detailed factorization of t can also be considered as the two semiinner is described in the following theorem.

A'

B'

ZZ

C’

re j

k

j

p-j-+-s2

l

tl

s1

‘B

r

sg

q - l*.- t 1 r Sl

Sl

,

=

i

i

Ci =

min (11 DE RPXQ

=

.=

?

a

1 1L%

65)

li

I

=

&9

+

i

zz 9

i=s+r+

C)
‘i

)...,S

i=l,...,

+

4

“9

89

+min(s,,s,

s+r+min(sl,s2

c

ve

n submatrices in some in

3.

LCORITHM. umns

of

CF;

we

obtain

II row rank, and c’,“’ = cl*).

nin

Step 5.

,,s _-WJJCret

of

-.

d

ces

e

result follows

is section we m

aracterization of the restricted singul

some preparations for the next section where we uct of three matrithe same dimension.

now on we will

arge numerical error when

ot explicitly forming the p

a*bove, we obtain

(4) Therefore the problem of finding he singular values of that of finding the singular values o and R, are upper triangular and h 2. m < n. Similarly to the above orthogonal sue

“’x”‘, and R, I E

- ‘AC-’

reduces to

“’x”’ are upper triangular.

Before we proceed to the next section, we will give an alternative preprocessing procedure. up with the triplet (A(;;,

form of one of the m

for the

vens 44-4

X

x X

x

X X

x

X X

X

X X

x

X X

X

X

X X X

X

X X

X

X

X

X

X X

X

X X

X X

X

X X

X

X

X

X

X

X X

-1 Q ii+1

i

=

ai+li+l

-1

X

9

ion concise,

resen

1

=a

we

wi

1

1

G?

%2

es.

;

1 .

a12

Q22 en

=

42 . a^22

a

in

Q-

+ 4 +

e

.

ing

-FB+92,-@es

ri j=r',,

ces are

in s

t

ANZ re consists 0

s.

ive

iagon

-1

=

-1

C

ces

s S

.

e

. -00 I

.

I

I

I

23

Ol’Tt’iJT

FOR

w

2.2904

-I.%508

I.4127

-0.7208

1.1723

-2.0553

-0.4267

0.462

0.0183

0.2217

O/l785

0.364

LA8546

-0.2497

0.2244

-0.4270

0.9989

-0.2949

1.2102

0.0000

0.0000

0.0000

0.0000

0

0

0

0

0.0000

0.9946

.OOOO

0.0000

0.0000

.7009

-0.0774

0.0000

0.0000

0

0

0.0000

0.0000

0.0000

0.5746

0.0000

0

0

0.0000

0.0000

0.0000

0.0000

0.2448

0.0000

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

where P and Q are nonsingular, and ?I and V are orthogonal. particular choice we have CondWl=35.2673,

For our

Csnd~Q~=$32.3483.

After the extraction procedure A is transformed to the form shown in Tablle 1. The matrix B is transformed to the form shown in Table 2, and the matrix C is transformed to the form shown in Table 3.

Columns

4 through 1.45'10

-3.1466 0.2594

-0.0582

0.3997

-0.04n

7 0.0562

0.0408

-0.2734

0.1298

0

-0.5657

-0.7552

-0.4533

0.1773

0

0.%495

-0.5582

-O.'lO91

O.S99

0

-1.3672

0.1429

-0.1206

-0.3251

0.6238

-a.'8328

0

0.4941

-0.0185

0.0110

0.0269

0.1%25

0.4309

0

-0.2445

0

6

0

0

8

2.2266

0

0

0

0

0

Columns

8

through

IO

0

e re

sin

en we

are

values usin

icesa!3 follows: # r-=3&? sl=2,

s2=2.

roblena: Formula-

sition

of matrix

t~~~et~,

rization and the general Gauss-

S