DLAED6(3F) DLAED6(3F)
DLAED6 - compute the positive or negative root (closest to the origin) of
z(1) z(2) z(3) f(x) = rho + --------- + ---------- + --------- d(1)-x
d(2)-x d(3)-x It is assumed that if ORGATI = .true
SUBROUTINE DLAED6( KNITER, ORGATI, RHO, D, Z, FINIT, TAU, INFO )
LOGICAL ORGATI
INTEGER INFO, KNITER
DOUBLE PRECISION FINIT, RHO, TAU
DOUBLE PRECISION D( 3 ), Z( 3 )
DLAED6 computes the positive or negative root (closest to the origin) of
z(1) z(2) z(3) f(x) = rho + --------- +
---------- + ---------
d(1)-x d(2)-x d(3)-x
otherwise it is between d(1) and d(2)
This routine will be called by DLAED4 when necessary. In most cases, the
root sought is the smallest in magnitude, though it might not be in some
extremely rare situations.
KNITER (input) INTEGER
Refer to DLAED4 for its significance.
ORGATI (input) LOGICAL
If ORGATI is true, the needed root is between d(2) and d(3);
otherwise it is between d(1) and d(2). See DLAED4 for
further details.
RHO (input) DOUBLE PRECISION
Refer to the equation f(x) above.
D (input) DOUBLE PRECISION array, dimension (3)
D satisfies d(1) < d(2) < d(3).
Z (input) DOUBLE PRECISION array, dimension (3)
Each of the elements in z must be positive.
FINIT (input) DOUBLE PRECISION
The value of f at 0. It is more accurate than the one
evaluated inside this routine (if someone wants to do so).
Page 1
DLAED6(3F) DLAED6(3F)
TAU (output) DOUBLE PRECISION
The root of the equation f(x).
INFO (output) INTEGER
= 0: successful exit
> 0: if INFO = 1, failure to converge
DLAED6(3F) DLAED6(3F)
DLAED6 - compute the positive or negative root (closest to the origin) of
z(1) z(2) z(3) f(x) = rho + --------- + ---------- + --------- d(1)-x
d(2)-x d(3)-x It is assumed that if ORGATI = .true
SUBROUTINE DLAED6( KNITER, ORGATI, RHO, D, Z, FINIT, TAU, INFO )
LOGICAL ORGATI
INTEGER INFO, KNITER
DOUBLE PRECISION FINIT, RHO, TAU
DOUBLE PRECISION D( 3 ), Z( 3 )
DLAED6 computes the positive or negative root (closest to the origin) of
z(1) z(2) z(3) f(x) = rho + --------- +
---------- + ---------
d(1)-x d(2)-x d(3)-x
otherwise it is between d(1) and d(2)
This routine will be called by DLAED4 when necessary. In most cases, the
root sought is the smallest in magnitude, though it might not be in some
extremely rare situations.
KNITER (input) INTEGER
Refer to DLAED4 for its significance.
ORGATI (input) LOGICAL
If ORGATI is true, the needed root is between d(2) and d(3);
otherwise it is between d(1) and d(2). See DLAED4 for
further details.
RHO (input) DOUBLE PRECISION
Refer to the equation f(x) above.
D (input) DOUBLE PRECISION array, dimension (3)
D satisfies d(1) < d(2) < d(3).
Z (input) DOUBLE PRECISION array, dimension (3)
Each of the elements in z must be positive.
FINIT (input) DOUBLE PRECISION
The value of f at 0. It is more accurate than the one
evaluated inside this routine (if someone wants to do so).
Page 1
DLAED6(3F) DLAED6(3F)
TAU (output) DOUBLE PRECISION
The root of the equation f(x).
INFO (output) INTEGER
= 0: successful exit
> 0: if INFO = 1, failure to converge
PPPPaaaaggggeeee 2222 [ Back ]
|
