Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?lasq4
Computes an approximation to the smallest eigenvalue using values of d from the previous transform. Used by ?bdsqr .
Syntax
call slasq4 ( i0 , n0 , z , pp , n0in , dmin , dmin1 , dmin2 , dn , dn1 , dn2 , tau , ttype , g )
call dlasq4 ( i0 , n0 , z , pp , n0in , dmin , dmin1 , dmin2 , dn , dn1 , dn2 , tau , ttype , g )
Include Files
mkl.fi
Description
slasq4 dlasq4
The routine computes an approximation tau to the smallest eigenvalue using values of d from the previous transform.
Input Parameters
- i0
-
INTEGER . First index.
- n0
-
INTEGER . Last index.
- z
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . Array, DIMENSION (4 n ). z holds the qd array.
- pp
-
INTEGER . pp=0 for ping, pp=1 for pong.
- n0in
-
INTEGER . The value of n0 at start of eigtest .
- dmin
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . Minimum value of d .
- dmin1
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . Minimum value of d , excluding d ( n0 ).
- dmin2
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . Minimum value of d , excluding d ( n0 ) and d ( n0 -1).
- dn
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . Contains d(n).
- dn1
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . Contains d(n-1).
- dn2
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . Contains d(n-2).
- g
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . A scalar passed as an argument in order to save its value between calls to ?lasq4 .
Output Parameters
- tau
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . Shift.
- ttype
-
INTEGER . Shift type.
- g
-
REAL for slasq4 DOUBLE PRECISION for dlasq4 . A scalar passed as an argument in order to save its value between calls to ?lasq4 .