Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 6/24/2024
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

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)

Description

The p?lawilroutine 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.



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.

See Also