122 SUBROUTINE dlaqr1( N, H, LDH, SR1, SI1, SR2, SI2, V )
130 DOUBLE PRECISION SI1, SI2, SR1, SR2
134 DOUBLE PRECISION H( ldh, * ), V( * )
140 DOUBLE PRECISION ZERO
141 parameter ( zero = 0.0d0 )
144 DOUBLE PRECISION H21S, H31S, S
151 s = abs( h( 1, 1 )-sr2 ) + abs( si2 ) + abs( h( 2, 1 ) )
157 v( 1 ) = h21s*h( 1, 2 ) + ( h( 1, 1 )-sr1 )*
158 $ ( ( h( 1, 1 )-sr2 ) / s ) - si1*( si2 / s )
159 v( 2 ) = h21s*( h( 1, 1 )+h( 2, 2 )-sr1-sr2 )
162 s = abs( h( 1, 1 )-sr2 ) + abs( si2 ) + abs( h( 2, 1 ) ) +
171 v( 1 ) = ( h( 1, 1 )-sr1 )*( ( h( 1, 1 )-sr2 ) / s ) -
172 $ si1*( si2 / s ) + h( 1, 2 )*h21s + h( 1, 3 )*h31s
173 v( 2 ) = h21s*( h( 1, 1 )+h( 2, 2 )-sr1-sr2 ) +
175 v( 3 ) = h31s*( h( 1, 1 )+h( 3, 3 )-sr1-sr2 ) +
subroutine dlaqr1(N, H, LDH, SR1, SI1, SR2, SI2, V)
DLAQR1 sets a scalar multiple of the first column of the product of 2-by-2 or 3-by-3 matrix H and spe...