slasq53lapack
Computes one dqds transform in ping-pong form, one version for ieee machines another for non ieee machines
Usage
- SUBROUTINE SLASQ5(
-
I0, N0, Z, PP, TAU, DMIN, DMIN1, DMIN2, DN, DNM1, DNM2, IEEE )
- LOGICAL
-
IEEE
- INTEGER
-
I0, N0, PP
- REAL
-
DMIN, DMIN1, DMIN2, DN, DNM1, DNM2, TAU
- REAL
-
Z( * )
Purpose
SLASQ5 computes one dqds transform in ping-pong form, one version for IEEE machines another for non IEEE machines.
Arguments
- I0 (input) INTEGER
-
First index.
- N0 (input) INTEGER
-
Last index.
- Z (input) REAL array, dimension ( 4*N )
-
Z holds the qd array. EMIN is stored in Z(4*N0) to avoid an extra argument.
- PP (input) INTEGER
-
PP=0 for ping, PP=1 for pong.
- TAU (input) REAL
-
This is the shift.
- DMIN (output) REAL
-
Minimum value of d. DMIN1 (output) REAL Minimum value of d, excluding D( N0 ). DMIN2 (output) REAL Minimum value of d, excluding D( N0 ) and D( N0-1 ).
- DN (output) REAL
-
d(N0), the last value of d.
- DNM1 (output) REAL
-
d(N0-1).
- DNM2 (output) REAL
-
d(N0-2).
- IEEE (input) LOGICAL
-
Flag for IEEE or non IEEE arithmetic.