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)

The p?lawil routine gets the transform given by h44, h33, and h43h34 into v starting at row m.

ii

(global) INTEGER.

Row owner of h(m+2, m+2).

jj

(global) INTEGER.

Column owner of h(m+2, m+2).

m

(global) INTEGER.

On entry, the location from where the transform starts (row m). Unchanged on exit.

a

(global)

REAL for pslawil

DOUBLE PRECISION for pdlawil

Array, DIMENSION (desca(lld_),*).

On entry, the Hessenberg matrix. Unchanged on exit.

desca

(global and local) INTEGER

Array of DIMENSION (dlen_). The array descriptor for the distributed matrix A. Unchanged on exit.

h43h34

(global)

REAL for pslawil

DOUBLE PRECISION for pdlawil

These three values are for the double shift QR iteration. Unchanged on exit.

v

(global)

REAL for pslawil

DOUBLE PRECISION for pdlawil

Array of size 3 that contains the transform on output.