1SLAZQ4(1)           LAPACK auxiliary routine (version 3.1)           SLAZQ4(1)
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NAME

6       SLAZQ4  -  an approximation TAU to the smallest eigenvalue using values
7       of d from the previous transform
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SYNOPSIS

10       SUBROUTINE SLAZQ4( I0, N0, Z, PP, N0IN, DMIN, DMIN1,  DMIN2,  DN,  DN1,
11                          DN2, TAU, TTYPE, G )
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13           INTEGER        I0, N0, N0IN, PP, TTYPE
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15           REAL           DMIN, DMIN1, DMIN2, DN, DN1, DN2, G, TAU
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17           REAL           Z( * )
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PURPOSE

20       SLAZQ4  computes  an approximation TAU to the smallest eigenvalue using
21       values of d from the previous transform.
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23       I0    (input) INTEGER
24             First index.
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26       N0    (input) INTEGER
27             Last index.
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29       Z     (input) REAL array, dimension ( 4*N )
30             Z holds the qd array.
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32       PP    (input) INTEGER
33             PP=0 for ping, PP=1 for pong.
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35       N0IN  (input) INTEGER
36             The value of N0 at start of EIGTEST.
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38       DMIN  (input) REAL
39             Minimum value of d.
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41       DMIN1 (input) REAL
42             Minimum value of d, excluding D( N0 ).
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44       DMIN2 (input) REAL
45             Minimum value of d, excluding D( N0 ) and D( N0-1 ).
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47       DN    (input) REAL
48             d(N)
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50       DN1   (input) REAL
51             d(N-1)
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53       DN2   (input) REAL
54             d(N-2)
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56       TAU   (output) REAL
57             This is the shift.
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59       TTYPE (output) INTEGER
60             Shift type.
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62       G     (input/output) REAL
63             G is passed as an argument in order to save its value between
64             calls to SLAZQ4
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FURTHER DETAILS

68       This is a thread safe version of SLASQ4, which  passes  G  through  the
69       argument list in place of declaring G in a SAVE statment.
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74 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006                       SLAZQ4(1)