101 SUBROUTINE zlapll( N, X, INCX, Y, INCY, SSMIN )
109 INTEGER INCX, INCY, N
110 DOUBLE PRECISION SSMIN
113 COMPLEX*16 X( * ), Y( * )
119 DOUBLE PRECISION ZERO
120 parameter( zero = 0.0d+0 )
122 parameter( cone = ( 1.0d+0, 0.0d+0 ) )
125 DOUBLE PRECISION SSMAX
126 COMPLEX*16 A11, A12, A22, C, TAU
129 INTRINSIC abs, dconjg
149 CALL
zlarfg( n, x( 1 ), x( 1+incx ), incx, tau )
153 c = -dconjg( tau )*zdotc( n, x, incx, y, incy )
154 CALL
zaxpy( n, c, x, incx, y, incy )
156 CALL
zlarfg( n-1, y( 1+incy ), y( 1+2*incy ), incy, tau )
163 CALL
dlas2( abs( a11 ), abs( a12 ), abs( a22 ), ssmin, ssmax )
subroutine zaxpy(N, ZA, ZX, INCX, ZY, INCY)
ZAXPY
subroutine zlapll(N, X, INCX, Y, INCY, SSMIN)
ZLAPLL measures the linear dependence of two vectors.
subroutine zlarfg(N, ALPHA, X, INCX, TAU)
ZLARFG generates an elementary reflector (Householder matrix).
subroutine dlas2(F, G, H, SSMIN, SSMAX)
DLAS2 computes singular values of a 2-by-2 triangular matrix.