dlasq4 (3p)

Name

dlasq4 - ues of d from the previous transform. Used by dbdsqr

Synopsis

SUBROUTINE DLASQ4(I0, N0, Z, PP, N0IN, DMIN,  DMIN1,  DMIN2,  DN,  DN1,
DN2, TAU, TTYPE, G)


INTEGER I0, N0, N0IN, PP, TTYPE

DOUBLE PRECISION DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, TAU

DOUBLE PRECISION Z(*)


SUBROUTINE  DLASQ4_64(I0, N0, Z, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1,
DN2, TAU, TTYPE, G)


INTEGER*8 I0, N0, N0IN, PP, TTYPE

DOUBLE PRECISION DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, TAU

DOUBLE PRECISION Z(*)


F95 INTERFACE
SUBROUTINE LASQ4(I0, N0, Z, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1, DN2,
TAU, TTYPE, G)


INTEGER :: I0, N0, PP, N0IN, TTYPE

REAL(8) :: DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, TAU

REAL(8) :: Z(*)


SUBROUTINE  LASQ4_64(I0,  N0, Z, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1,
DN2, TAU, TTYPE, G)


INTEGER(8) :: I0, N0, PP, N0IN, TTYPE

REAL(8) :: DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, TAU

REAL(8) :: Z(*)


C INTERFACE
#include <sunperf.h>

void dlasq4 (int i0, int n0, double *z, int pp, int n0in, double  dmin,
double  dmin1,  double  dmin2,  double dn, double dn1, double
dn2, double *tau, int *ttype, double *g);


void dlasq4_64 (long i0, long n0, double *z, long pp, long n0in, double
dmin, double dmin1, double dmin2, double dn, double dn1, dou-
ble dn2, double *tau, long *ttype, double *g);

Description

Oracle Solaris Studio Performance Library                           dlasq4(3P)



NAME
       dlasq4 - compute an approximation to the smallest eigenvalue using val-
       ues of d from the previous transform. Used by dbdsqr


SYNOPSIS
       SUBROUTINE DLASQ4(I0, N0, Z, PP, N0IN, DMIN,  DMIN1,  DMIN2,  DN,  DN1,
                 DN2, TAU, TTYPE, G)


       INTEGER I0, N0, N0IN, PP, TTYPE

       DOUBLE PRECISION DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, TAU

       DOUBLE PRECISION Z(*)


       SUBROUTINE  DLASQ4_64(I0, N0, Z, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1,
                 DN2, TAU, TTYPE, G)


       INTEGER*8 I0, N0, N0IN, PP, TTYPE

       DOUBLE PRECISION DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, TAU

       DOUBLE PRECISION Z(*)


   F95 INTERFACE
       SUBROUTINE LASQ4(I0, N0, Z, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1, DN2,
                 TAU, TTYPE, G)


       INTEGER :: I0, N0, PP, N0IN, TTYPE

       REAL(8) :: DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, TAU

       REAL(8) :: Z(*)


       SUBROUTINE  LASQ4_64(I0,  N0, Z, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1,
                 DN2, TAU, TTYPE, G)


       INTEGER(8) :: I0, N0, PP, N0IN, TTYPE

       REAL(8) :: DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, TAU

       REAL(8) :: Z(*)


   C INTERFACE
       #include <sunperf.h>

       void dlasq4 (int i0, int n0, double *z, int pp, int n0in, double  dmin,
                 double  dmin1,  double  dmin2,  double dn, double dn1, double
                 dn2, double *tau, int *ttype, double *g);


       void dlasq4_64 (long i0, long n0, double *z, long pp, long n0in, double
                 dmin, double dmin1, double dmin2, double dn, double dn1, dou-
                 ble dn2, double *tau, long *ttype, double *g);


PURPOSE
       dlasq4 computes an approximation TAU to the smallest  eigenvalue  using
       values of d from the previous transform.


ARGUMENTS
       I0 (input)
                 I0 is INTEGER
                 First index.


       N0 (input)
                 N0 is INTEGER
                 Last index.


       Z (input)
                 Z is DOUBLE PRECISION array, dimension (4*N)
                 Z holds the qd array.


       PP (input)
                 PP is INTEGER
                 PP=0 for ping, PP=1 for pong.


       N0IN (input)
                 N0IN is INTEGER
                 The value of N0 at start of EIGTEST.


       DMIN (input)
                 DMIN is DOUBLE PRECISION
                 Minimum value of d.


       DMIN1 (input)
                 DMIN1 is DOUBLE PRECISION
                 Minimum value of d, excluding D(N0).


       DMIN2 (input)
                 DMIN2 is DOUBLE PRECISION
                 Minimum value of d, excluding D(N0) and D(N0-1).


       DN (input)
                 DN is DOUBLE PRECISION
                 d(N)


       DN1 (input)
                 DN1 is DOUBLE PRECISION
                 d(N-1)


       DN2 (input)
                 DN2 is DOUBLE PRECISION
                 d(N-2)


       TAU (output)
                 TAU is DOUBLE PRECISION
                 This is the shift.


       TTYPE (output)
                 TTYPE is INTEGER
                 Shift type.


       G (input/output)
                 G is REAL
                 G is passed as an argument in order to save its value between
                 calls to DLASQ4.




                                  7 Nov 2015                        dlasq4(3P)