slasq4(l) — SunSoft Performance Library
NAME
slasq4 - SLASQ4 estimates TAU, the smallest eigenvalue of a matrix
SYNOPSIS
SUBROUTINE SLASQ4(
N, Q, E, TAU, SUP )
INTEGER N
REAL SUP, TAU
REAL E( ∗ ), Q( ∗ )
PURPOSE
SLASQ4 estimates TAU, the smallest eigenvalue of a matrix. This
routine improves the input value of SUP which is an upper bound
for the smallest eigenvalue for this matrix .
ARGUMENTS
N (input) INTEGER
On entry, N specifies the number of rows and columns in the matrix. N must be at least 0.
Q (input) REAL array, dimension (N)
Q array
E (input) REAL array, dimension (N)
E array
TAU (output) REAL
Estimate of the shift
SUP (input/output) REAL
Upper bound for the smallest singular value
SunSoft, Inc. — Last change: 27 Jun 1995