## MB02CY

### Applying the MB02CX transformations on other columns / rows of the generator

[Specification] [Arguments] [Method] [References] [Comments] [Example]

Purpose

```  To apply the transformations created by the SLICOT Library
routine MB02CX on other columns / rows of the generator,
contained in the arrays A and B of positive and negative
generators, respectively.

```
Specification
```      SUBROUTINE MB02CY( TYPET, STRUCG, P, Q, N, K, A, LDA, B, LDB, H,
\$                   LDH, CS, LCS, DWORK, LDWORK, INFO )
C     .. Scalar Arguments ..
INTEGER           INFO, K, LDA, LDB, LCS, LDH, LDWORK, N, P, Q
CHARACTER         STRUCG, TYPET
C     .. Array Arguments ..
DOUBLE PRECISION  A(LDA, *), B(LDB, *), CS(*), DWORK(*), H(LDH,*)

```
Arguments

Mode Parameters

```  TYPET   CHARACTER*1
Specifies the type of the generator, as follows:
= 'R':  A and B are additional columns of the generator;
= 'C':  A and B are additional rows of the generator.
Note:   in the sequel, the notation x / y means that
x corresponds to TYPET = 'R' and y corresponds to
TYPET = 'C'.

STRUCG  CHARACTER*1
Information about the structure of the two generators,
as follows:
= 'T':  the trailing block of the positive generator
is lower / upper triangular, and the trailing
block of the negative generator is zero;
= 'N':  no special structure to mention.

```
Input/Output Parameters
```  P       (input)  INTEGER
The number of rows / columns in A containing the positive
generators.  P >= 0.

Q       (input)  INTEGER
The number of rows / columns in B containing the negative
generators.  Q >= 0.

N       (input)  INTEGER
The number of columns / rows in A and B to be processed.
N >= 0.

K       (input)  INTEGER
The number of columns / rows in H.  P >= K >= 0.

A       (input/output)  DOUBLE PRECISION array, dimension
(LDA, N) / (LDA, P)
On entry, the leading P-by-N / N-by-P part of this array
must contain the positive part of the generator.
On exit, the leading P-by-N / N-by-P part of this array
contains the transformed positive part of the generator.

LDA     INTEGER
The leading dimension of the array A.
LDA >= MAX(1,P),    if TYPET = 'R';
LDA >= MAX(1,N),    if TYPET = 'C'.

B       (input/output)  DOUBLE PRECISION array, dimension
(LDB, N) / (LDB, Q)
On entry, the leading Q-by-N / N-by-Q part of this array
must contain the negative part of the generator.
On exit, the leading Q-by-N / N-by-Q part of this array
contains the transformed negative part of the generator.

LDB     INTEGER
The leading dimension of the array B.
LDB >= MAX(1,Q),    if TYPET = 'R';
LDB >= MAX(1,N),    if TYPET = 'C'.

H       (input)  DOUBLE PRECISION array, dimension
(LDH, K) / (LDH, Q)
The leading Q-by-K / K-by-Q part of this array must
contain part of the necessary information for the
Householder transformations computed by SLICOT Library
routine MB02CX.

LDH     INTEGER
The leading dimension of the array H.
LDH >= MAX(1,Q),    if TYPET = 'R';
LDH >= MAX(1,K),    if TYPET = 'C'.

CS      (input)  DOUBLE PRECISION array, dimension (LCS)
The leading 2*K + MIN(K,Q) part of this array must
contain the necessary information for modified hyperbolic
rotations and the scalar factors of the Householder
transformations computed by SLICOT Library routine MB02CX.

LCS     INTEGER
The length of the array CS.  LCS >= 2*K + MIN(K,Q).

```
Workspace
```  DWORK   DOUBLE PRECISION array, dimension (LDWORK)
On exit, if  INFO = 0,  DWORK(1)  returns the optimal
value of LDWORK.
On exit, if  INFO = -16,  DWORK(1)  returns the minimum
value of LDWORK.

LDWORK  INTEGER
The length of the array DWORK.  LDWORK >= MAX(1,N).
For optimum performance LDWORK should be larger.

```
Error Indicator
```  INFO    INTEGER
= 0:  succesful exit;
< 0:  if INFO = -i, the i-th argument had an illegal
value.

```
Method
```  The Householder transformations and modified hyperbolic rotations
computed by SLICOT Library routine MB02CX are applied to the
corresponding parts of the matrices A and B.

```
```  None
```
Example

Program Text

```  None
```
Program Data
```  None
```
Program Results
```  None
```