# zdrvst2stg.f - Man Page

TESTING/EIG/zdrvst2stg.f

## Synopsis

### Functions/Subroutines

subroutine zdrvst2stg (nsizes, nn, ntypes, dotype, iseed, thresh, nounit, a, lda, d1, d2, d3, wa1, wa2, wa3, u, ldu, v, tau, z, work, lwork, rwork, lrwork, iwork, liwork, result, info)
ZDRVST2STG

## Function/Subroutine Documentation

### subroutine zdrvst2stg (integer nsizes, integer, dimension( * ) nn, integer ntypes, logical, dimension( * ) dotype, integer, dimension( 4 ) iseed, double precision thresh, integer nounit, complex*16, dimension( lda, * ) a, integer lda, double precision, dimension( * ) d1, double precision, dimension( * ) d2, double precision, dimension( * ) d3, double precision, dimension( * ) wa1, double precision, dimension( * ) wa2, double precision, dimension( * ) wa3, complex*16, dimension( ldu, * ) u, integer ldu, complex*16, dimension( ldu, * ) v, complex*16, dimension( * ) tau, complex*16, dimension( ldu, * ) z, complex*16, dimension( * ) work, integer lwork, double precision, dimension( * ) rwork, integer lrwork, integer, dimension( * ) iwork, integer liwork, double precision, dimension( * ) result, integer info)

ZDRVST2STG

Purpose:

```      ZDRVST2STG  checks the Hermitian eigenvalue problem drivers.

ZHEEVD computes all eigenvalues and, optionally,
eigenvectors of a complex Hermitian matrix,
using a divide-and-conquer algorithm.

ZHEEVX computes selected eigenvalues and, optionally,
eigenvectors of a complex Hermitian matrix.

ZHEEVR computes selected eigenvalues and, optionally,
eigenvectors of a complex Hermitian matrix
using the Relatively Robust Representation where it can.

ZHPEVD computes all eigenvalues and, optionally,
eigenvectors of a complex Hermitian matrix in packed
storage, using a divide-and-conquer algorithm.

ZHPEVX computes selected eigenvalues and, optionally,
eigenvectors of a complex Hermitian matrix in packed
storage.

ZHBEVD computes all eigenvalues and, optionally,
eigenvectors of a complex Hermitian band matrix,
using a divide-and-conquer algorithm.

ZHBEVX computes selected eigenvalues and, optionally,
eigenvectors of a complex Hermitian band matrix.

ZHEEV computes all eigenvalues and, optionally,
eigenvectors of a complex Hermitian matrix.

ZHPEV computes all eigenvalues and, optionally,
eigenvectors of a complex Hermitian matrix in packed
storage.

ZHBEV computes all eigenvalues and, optionally,
eigenvectors of a complex Hermitian band matrix.

When ZDRVST2STG is called, a number of matrix 'sizes' ('n's') and a
number of matrix 'types' are specified.  For each size ('n')
and each type of matrix, one matrix will be generated and used
to test the appropriate drivers.  For each matrix and each
driver routine called, the following tests will be performed:

(1)     | A - Z D Z' | / ( |A| n ulp )

(2)     | I - Z Z' | / ( n ulp )

(3)     | D1 - D2 | / ( |D1| ulp )

where Z is the matrix of eigenvectors returned when the
eigenvector option is given and D1 and D2 are the eigenvalues
returned with and without the eigenvector option.

The 'sizes' are specified by an array NN(1:NSIZES); the value of
each element NN(j) specifies one size.
The 'types' are specified by a logical array DOTYPE( 1:NTYPES );
if DOTYPE(j) is .TRUE., then matrix type 'j' will be generated.
Currently, the list of possible types is:

(1)  The zero matrix.
(2)  The identity matrix.

(3)  A diagonal matrix with evenly spaced entries
1, ..., ULP  and random signs.
(ULP = (first number larger than 1) - 1 )
(4)  A diagonal matrix with geometrically spaced entries
1, ..., ULP  and random signs.
(5)  A diagonal matrix with 'clustered' entries 1, ULP, ..., ULP
and random signs.

(6)  Same as (4), but multiplied by SQRT( overflow threshold )
(7)  Same as (4), but multiplied by SQRT( underflow threshold )

(8)  A matrix of the form  U* D U, where U is unitary and
D has evenly spaced entries 1, ..., ULP with random signs
on the diagonal.

(9)  A matrix of the form  U* D U, where U is unitary and
D has geometrically spaced entries 1, ..., ULP with random
signs on the diagonal.

(10) A matrix of the form  U* D U, where U is unitary and
D has 'clustered' entries 1, ULP,..., ULP with random
signs on the diagonal.

(11) Same as (8), but multiplied by SQRT( overflow threshold )
(12) Same as (8), but multiplied by SQRT( underflow threshold )

(13) Symmetric matrix with random entries chosen from (-1,1).
(14) Same as (13), but multiplied by SQRT( overflow threshold )
(15) Same as (13), but multiplied by SQRT( underflow threshold )
(16) A band matrix with half bandwidth randomly chosen between
0 and N-1, with evenly spaced eigenvalues 1, ..., ULP
with random signs.
(17) Same as (16), but multiplied by SQRT( overflow threshold )
(18) Same as (16), but multiplied by SQRT( underflow threshold )```
```  NSIZES  INTEGER
The number of sizes of matrices to use.  If it is zero,
ZDRVST2STG does nothing.  It must be at least zero.
Not modified.

NN      INTEGER array, dimension (NSIZES)
An array containing the sizes to be used for the matrices.
Zero values will be skipped.  The values must be at least
zero.
Not modified.

NTYPES  INTEGER
The number of elements in DOTYPE.   If it is zero, ZDRVST2STG
does nothing.  It must be at least zero.  If it is MAXTYP+1
and NSIZES is 1, then an additional type, MAXTYP+1 is
defined, which is to use whatever matrix is in A.  This
is only useful if DOTYPE(1:MAXTYP) is .FALSE. and
DOTYPE(MAXTYP+1) is .TRUE. .
Not modified.

DOTYPE  LOGICAL array, dimension (NTYPES)
If DOTYPE(j) is .TRUE., then for each size in NN a
matrix of that size and of type j will be generated.
If NTYPES is smaller than the maximum number of types
defined (PARAMETER MAXTYP), then types NTYPES+1 through
MAXTYP will not be generated.  If NTYPES is larger
than MAXTYP, DOTYPE(MAXTYP+1) through DOTYPE(NTYPES)
will be ignored.
Not modified.

ISEED   INTEGER array, dimension (4)
On entry ISEED specifies the seed of the random number
generator. The array elements should be between 0 and 4095;
if not they will be reduced mod 4096.  Also, ISEED(4) must
be odd.  The random number generator uses a linear
congruential sequence limited to small integers, and so
should produce machine independent random numbers. The
values of ISEED are changed on exit, and can be used in the
next call to ZDRVST2STG to continue the same random number
sequence.
Modified.

THRESH  DOUBLE PRECISION
A test will count as 'failed' if the 'error', computed as
described above, exceeds THRESH.  Note that the error
is scaled to be O(1), so THRESH should be a reasonably
small multiple of 1, e.g., 10 or 100.  In particular,
it should not depend on the precision (single vs. double)
or the size of the matrix.  It must be at least zero.
Not modified.

NOUNIT  INTEGER
The FORTRAN unit number for printing out error messages
(e.g., if a routine returns IINFO not equal to 0.)
Not modified.

A       COMPLEX*16 array, dimension (LDA , max(NN))
Used to hold the matrix whose eigenvalues are to be
computed.  On exit, A contains the last matrix actually
used.
Modified.

LDA     INTEGER
The leading dimension of A.  It must be at
least 1 and at least max( NN ).
Not modified.

D1      DOUBLE PRECISION array, dimension (max(NN))
The eigenvalues of A, as computed by ZSTEQR simultaneously
with Z.  On exit, the eigenvalues in D1 correspond with the
matrix in A.
Modified.

D2      DOUBLE PRECISION array, dimension (max(NN))
The eigenvalues of A, as computed by ZSTEQR if Z is not
computed.  On exit, the eigenvalues in D2 correspond with
the matrix in A.
Modified.

D3      DOUBLE PRECISION array, dimension (max(NN))
The eigenvalues of A, as computed by DSTERF.  On exit, the
eigenvalues in D3 correspond with the matrix in A.
Modified.

WA1     DOUBLE PRECISION array, dimension

WA2     DOUBLE PRECISION array, dimension

WA3     DOUBLE PRECISION array, dimension

U       COMPLEX*16 array, dimension (LDU, max(NN))
The unitary matrix computed by ZHETRD + ZUNGC3.
Modified.

LDU     INTEGER
The leading dimension of U, Z, and V.  It must be at
least 1 and at least max( NN ).
Not modified.

V       COMPLEX*16 array, dimension (LDU, max(NN))
The Housholder vectors computed by ZHETRD in reducing A to
tridiagonal form.
Modified.

TAU     COMPLEX*16 array, dimension (max(NN))
The Householder factors computed by ZHETRD in reducing A
to tridiagonal form.
Modified.

Z       COMPLEX*16 array, dimension (LDU, max(NN))
The unitary matrix of eigenvectors computed by ZHEEVD,
ZHEEVX, ZHPEVD, CHPEVX, ZHBEVD, and CHBEVX.
Modified.

WORK  - COMPLEX*16 array of dimension ( LWORK )
Workspace.
Modified.

LWORK - INTEGER
The number of entries in WORK.  This must be at least
2*max( NN(j), 2 )**2.
Not modified.

RWORK   DOUBLE PRECISION array, dimension (3*max(NN))
Workspace.
Modified.

LRWORK - INTEGER
The number of entries in RWORK.

IWORK   INTEGER array, dimension (6*max(NN))
Workspace.
Modified.

LIWORK - INTEGER
The number of entries in IWORK.

RESULT  DOUBLE PRECISION array, dimension (??)
The values computed by the tests described above.
The values are currently limited to 1/ulp, to avoid
overflow.
Modified.

INFO    INTEGER
If 0, then everything ran OK.
-1: NSIZES < 0
-2: Some NN(j) < 0
-3: NTYPES < 0
-5: THRESH < 0
-9: LDA < 1 or LDA < NMAX, where NMAX is max( NN(j) ).
-16: LDU < 1 or LDU < NMAX.
-21: LWORK too small.
If  DLATMR, SLATMS, ZHETRD, DORGC3, ZSTEQR, DSTERF,
or DORMC2 returns an error code, the
absolute value of it is returned.
Modified.

-----------------------------------------------------------------------

Some Local Variables and Parameters:
---- ----- --------- --- ----------
ZERO, ONE       Real 0 and 1.
MAXTYP          The number of types defined.
NTEST           The number of tests performed, or which can
be performed so far, for the current matrix.
NTESTT          The total number of tests performed so far.
NMAX            Largest value in NN.
NMATS           The number of matrices generated so far.
NERRS           The number of tests which have exceeded THRESH
so far (computed by DLAFTS).
COND, IMODE     Values to be passed to the matrix generators.
ANORM           Norm of A; passed to matrix generators.

OVFL, UNFL      Overflow and underflow thresholds.
ULP, ULPINV     Finest relative precision and its inverse.
RTOVFL, RTUNFL  Square roots of the previous 2 values.
The following four arrays decode JTYPE:
KTYPE(j)        The general type (1-10) for type 'j'.
KMODE(j)        The MODE value to be passed to the matrix
generator for type 'j'.
KMAGN(j)        The order of magnitude ( O(1),
O(overflow^(1/2) ), O(underflow^(1/2) )```
Author

Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Definition at line 334 of file zdrvst2stg.f.

## Author

Generated automatically by Doxygen for LAPACK from the source code.

## Referenced By

The man page zdrvst2stg(3) is an alias of zdrvst2stg.f(3).

Tue Nov 28 2023 12:08:42 Version 3.12.0 LAPACK