slasq4(3)

NAME

SLASQ4 - compute an approximation TAU to the smallest

eigenvalue using values of d from the previous transform

SYNOPSIS

SUBROUTINE  SLASQ4(  I0,  N0,  Z,  PP,  N0IN, DMIN, DMIN1,
DMIN2, DN, DN1, DN2, TAU, TTYPE )
    INTEGER        I0, N0, N0IN, PP, TTYPE
    REAL           DMIN, DMIN1, DMIN2, DN, DN1, DN2, TAU
    REAL           Z( * )

PURPOSE

SLASQ4 computes an approximation TAU to the smallest

eigenvalue using values of d from the previous transform. I0

(input) INTEGER

First index.

N0 (input) INTEGER

Last index.

Z (input) REAL array, dimension ( 4*N )

Z holds the qd array.

PP (input) INTEGER

PP=0 for ping, PP=1 for pong.

NOIN (input) INTEGER

The value of N0 at start of EIGTEST.

DMIN (input) REAL

Minimum value of d.

DMIN1 (input) REAL

Minimum value of d, excluding D( N0 ).

DMIN2 (input) REAL

Minimum value of d, excluding D( N0 ) and D( N0-1 ).

DN (input) REAL

d(N)

DN1 (input) REAL

d(N-1)

DN2 (input) REAL

d(N-2)

TAU (output) REAL

This is the shift.

TTYPE (output) INTEGER

Shift type.

FURTHER DETAILS

SLASQ4(3)