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LAPACK
3.7.0
LAPACK: Linear Algebra PACKage
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| subroutine slasq5 | ( | integer | I0, |
| integer | N0, | ||
| real, dimension( * ) | Z, | ||
| integer | PP, | ||
| real | TAU, | ||
| real | SIGMA, | ||
| real | DMIN, | ||
| real | DMIN1, | ||
| real | DMIN2, | ||
| real | DN, | ||
| real | DNM1, | ||
| real | DNM2, | ||
| logical | IEEE, | ||
| real | EPS | ||
| ) |
SLASQ5 computes one dqds transform in ping-pong form. Used by sbdsqr and sstegr.
Download SLASQ5 + dependencies [TGZ] [ZIP] [TXT]
SLASQ5 computes one dqds transform in ping-pong form, one version for IEEE machines another for non IEEE machines.
| [in] | I0 | I0 is INTEGER
First index. |
| [in] | N0 | N0 is INTEGER
Last index. |
| [in] | Z | Z is REAL array, dimension ( 4*N )
Z holds the qd array. EMIN is stored in Z(4*N0) to avoid
an extra argument. |
| [in] | PP | PP is INTEGER
PP=0 for ping, PP=1 for pong. |
| [in] | TAU | TAU is REAL
This is the shift. |
| [in] | SIGMA | SIGMA is REAL
This is the accumulated shift up to this step. |
| [out] | DMIN | DMIN is REAL
Minimum value of d. |
| [out] | DMIN1 | DMIN1 is REAL
Minimum value of d, excluding D( N0 ). |
| [out] | DMIN2 | DMIN2 is REAL
Minimum value of d, excluding D( N0 ) and D( N0-1 ). |
| [out] | DN | DN is REAL
d(N0), the last value of d. |
| [out] | DNM1 | DNM1 is REAL
d(N0-1). |
| [out] | DNM2 | DNM2 is REAL
d(N0-2). |
| [in] | IEEE | IEEE is LOGICAL
Flag for IEEE or non IEEE arithmetic. |
| [in] | EPS | EPS is REAL
This is the value of epsilon used. |