103 SUBROUTINE dlapll( N, X, INCX, Y, INCY, SSMIN )
111 INTEGER incx, incy, n
112 DOUBLE PRECISION ssmin
115 DOUBLE PRECISION x( * ), y( * )
121 DOUBLE PRECISION zero, one
122 parameter( zero = 0.0d+0, one = 1.0d+0 )
125 DOUBLE PRECISION a11, a12, a22, c, ssmax, tau
128 DOUBLE PRECISION ddot
145 CALL
dlarfg( n,
x( 1 ),
x( 1+incx ), incx, tau )
149 c = -tau*
ddot( n,
x, incx, y, incy )
150 CALL
daxpy( n, c,
x, incx, y, incy )
152 CALL
dlarfg( n-1, y( 1+incy ), y( 1+2*incy ), incy, tau )
159 CALL
dlas2( a11, a12, a22, ssmin, ssmax )
subroutine dlapll(N, X, INCX, Y, INCY, SSMIN)
DLAPLL measures the linear dependence of two vectors.
subroutine dlarfg(N, ALPHA, X, INCX, TAU)
DLARFG generates an elementary reflector (Householder matrix).
subroutine daxpy(N, DA, DX, INCX, DY, INCY)
DAXPY
DOUBLE PRECISION function ddot(N, DX, INCX, DY, INCY)
DDOT
subroutine dlas2(F, G, H, SSMIN, SSMAX)
DLAS2 computes singular values of a 2-by-2 triangular matrix.