Visible to Intel only — GUID: GUID-A8989121-7C38-46E2-839B-99A1FB8EF8E9
Visible to Intel only — GUID: GUID-A8989121-7C38-46E2-839B-99A1FB8EF8E9
?lasq5
Computes one dqds transform in ping-pong form. Used by ?bdsqr and ?stegr.
Syntax
call slasq5( i0, n0, z, pp, tau, sigma, dmin, dmin1, dmin2, dn, dnm1, dnm2, ieee, eps )
call dlasq5( i0, n0, z, pp, tau, sigma, dmin, dmin1, dmin2, dn, dnm1, dnm2, ieee, eps )
Include Files
- mkl.fi
Description
The routine computes one dqds transform in ping-pong form: one version for ieee machines, another for non-ieee machines.
Input Parameters
- i0
-
INTEGER. First index.
- n0
-
INTEGER. Last index.
- z
-
REAL for slasq5
DOUBLE PRECISION for dlasq5.
Array, DIMENSION (4n). z holds the qd array. emin is stored in z(4*n0)
to avoid an extra argument.
- pp
-
INTEGER. pp=0 for ping, pp=1 for pong.
- tau
-
REAL for slasq5
DOUBLE PRECISION for dlasq5.
This is the shift.
- sigma
-
REAL for slasq5
DOUBLE PRECISION for dlasq5.
This is the accumulated shift up to the current point.
- ieee
-
LOGICAL. Flag for IEEE or non-IEEE arithmetic.
- eps
-
REAL for slasq5
DOUBLE PRECISION for dlasq5.
This is the value of epsilon used.
Output Parameters
- dmin
-
REAL for slasq5
DOUBLE PRECISION for dlasq5.
Minimum value of d.
- dmin1
-
REAL for slasq5
DOUBLE PRECISION for dlasq5.
Minimum value of d, excluding d(n0).
- dmin2
-
REAL for slasq5
DOUBLE PRECISION for dlasq5.
Minimum value of d, excluding d(n0) and d(n0-1).
- dn
-
REAL for slasq5
DOUBLE PRECISION for dlasq5. Contains d(n0), the last value of d.
- dnm1
-
REAL for slasq5
DOUBLE PRECISION for dlasq5. Contains d(n0-1).
- dnm2
-
REAL for slasq5
DOUBLE PRECISION for dlasq5. Contains d(n0-2).