Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
p?lawil
Forms the Wilkinson transform.
Syntax
call pslawil ( ii , jj , m , a , desca , h44 , h33 , h43h34 , v )
call pdlawil ( ii , jj , m , a , desca , h44 , h33 , h43h34 , v )
call pclawil ( ii , jj , m , a , desca , h44 , h33 , h43h34 , v )
call pzlawil ( ii , jj , m , a , desca , h44 , h33 , h43h34 , v )
Include Files
mkl_scalapack.h
Description
pslawil pdlawil pclawil pzlawil The p?lawil routine function gets the transform given by h44 , h33 , and h43h34 into v starting at row m .
Input Parameters
ii
(global) INTEGER .
Number of the process row which owns the matrix element A ( m +2, m +2).
jj
(global) INTEGER .
Number of the process column which owns the matrix element A ( m +2, m +2).
m
(global) INTEGER .
On entry, the location from where the transform starts (row m ). Unchanged on exit.
- a
-
(local) REAL for pslawil DOUBLE PRECISION for pdlawil COMPLEX for pclawil DOUBLE COMPLEX for pzlawil
Array of size (lld_a,LOCc(n_a)) .
On entry, the Hessenberg matrix. Unchanged on exit.
- desca
-
(global and local) INTEGER Array of size dlen_ . The array descriptor for the distributed matrix A . Unchanged on exit.
- h44 , h33 , h43h34
-
(global) REAL for pslawil DOUBLE PRECISION for pdlawil COMPLEX for pclawil DOUBLE COMPLEX for pzlawil These three values are for the double shift QR iteration. Unchanged on exit.
Output Parameters
- v
-
(global) REAL for pslawil DOUBLE PRECISION for pdlawil COMPLEX for pclawil DOUBLE COMPLEX for pzlawil Array of size 3 that contains the transform on output.