Scroll to navigation

slasq4.f(3) LAPACK slasq4.f(3)

NAME

slasq4.f -

SYNOPSIS

Functions/Subroutines


subroutine slasq4 (I0, N0, Z, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1, DN2, TAU, TTYPE, G)
 
SLASQ4 computes an approximation to the smallest eigenvalue using values of d from the previous transform. Used by sbdsqr.

Function/Subroutine Documentation

subroutine slasq4 (integerI0, integerN0, real, dimension( * )Z, integerPP, integerN0IN, realDMIN, realDMIN1, realDMIN2, realDN, realDN1, realDN2, realTAU, integerTTYPE, realG)

SLASQ4 computes an approximation to the smallest eigenvalue using values of d from the previous transform. Used by sbdsqr.
Purpose: 
 SLASQ4 computes an approximation TAU to the smallest eigenvalue
 using values of d from the previous transform.
Parameters:
I0 
          I0 is INTEGER
        First index.
N0 
          N0 is INTEGER
        Last index.
Z 
          Z is REAL array, dimension ( 4*N )
        Z holds the qd array.
PP 
          PP is INTEGER
        PP=0 for ping, PP=1 for pong.
N0IN 
          N0IN is INTEGER
        The value of N0 at start of EIGTEST.
DMIN 
          DMIN is REAL
        Minimum value of d.
DMIN1 
          DMIN1 is REAL
        Minimum value of d, excluding D( N0 ).
DMIN2 
          DMIN2 is REAL
        Minimum value of d, excluding D( N0 ) and D( N0-1 ).
DN 
          DN is REAL
        d(N)
DN1 
          DN1 is REAL
        d(N-1)
DN2 
          DN2 is REAL
        d(N-2)
TAU 
          TAU is REAL
        This is the shift.
TTYPE 
          TTYPE is INTEGER
        Shift type.
G 
          G is REAL
        G is passed as an argument in order to save its value between
        calls to SLASQ4.
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
September 2012
Further Details: 
  CNST1 = 9/16
Definition at line 151 of file slasq4.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.
Wed Oct 15 2014 Version 3.4.2