DLASQ4(3F)DLASQ4(3F)NAMEDLASQ4 - DLASQ4 estimates TAU, the smallest eigenvalue of a matrix
SYNOPSIS
SUBROUTINE DLASQ4( N, Q, E, TAU, SUP )
INTEGER N
DOUBLE PRECISION SUP, TAU
DOUBLE PRECISION E( * ), Q( * )
PURPOSEDLASQ4 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) DOUBLE PRECISION array, dimension (N)
Q array
E (input) DOUBLE PRECISION array, dimension (N)
E array
TAU (output) DOUBLE PRECISION
Estimate of the shift
SUP (input/output) DOUBLE PRECISION
Upper bound for the smallest singular value
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