1DLASQ6(1) LAPACK auxiliary routine (version 3.1) DLASQ6(1)
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6 DLASQ6 - one dqd (shift equal to zero) transform in ping-pong form,
7 with protection against underflow and overflow
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10 SUBROUTINE DLASQ6( I0, N0, Z, PP, DMIN, DMIN1, DMIN2, DN, DNM1, DNM2 )
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12 INTEGER I0, N0, PP
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14 DOUBLE PRECISION DMIN, DMIN1, DMIN2, DN, DNM1, DNM2
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16 DOUBLE PRECISION Z( * )
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19 DLASQ6 computes one dqd (shift equal to zero) transform in ping-pong
20 form, with protection against underflow and overflow.
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24 I0 (input) INTEGER
25 First index.
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27 N0 (input) INTEGER
28 Last index.
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30 Z (input) DOUBLE PRECISION array, dimension ( 4*N )
31 Z holds the qd array. EMIN is stored in Z(4*N0) to avoid an extra
32 argument.
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34 PP (input) INTEGER
35 PP=0 for ping, PP=1 for pong.
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37 DMIN (output) DOUBLE PRECISION
38 Minimum value of d.
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40 DMIN1 (output) DOUBLE PRECISION Minimum value of d, excluding D(
41 N0 ).
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43 DMIN2 (output) DOUBLE PRECISION Minimum value of d, excluding D(
44 N0 ) and D( N0-1 ).
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46 DN (output) DOUBLE PRECISION
47 d(N0), the last value of d.
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49 DNM1 (output) DOUBLE PRECISION
50 d(N0-1).
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52 DNM2 (output) DOUBLE PRECISION
53 d(N0-2).
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57 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006 DLASQ6(1)