larfy - Man Page

subroutine clarfy (uplo, n, v, incv, tau, c, ldc, work)
CLARFY
subroutine dlarfy (uplo, n, v, incv, tau, c, ldc, work)
DLARFY
subroutine slarfy (uplo, n, v, incv, tau, c, ldc, work)
SLARFY
subroutine zlarfy (uplo, n, v, incv, tau, c, ldc, work)
ZLARFY

CLARFY

Purpose:

 CLARFY applies an elementary reflector, or Householder matrix, H,
 to an n x n Hermitian matrix C, from both the left and the right.

 H is represented in the form

    H = I - tau * v * v'

 where  tau  is a scalar and  v  is a vector.

 If  tau  is  zero, then  H  is taken to be the unit matrix.

Parameters

UPLO

          UPLO is CHARACTER*1
          Specifies whether the upper or lower triangular part of the
          Hermitian matrix C is stored.
          = 'U':  Upper triangle
          = 'L':  Lower triangle

N

          N is INTEGER
          The number of rows and columns of the matrix C.  N >= 0.

V

          V is COMPLEX array, dimension
                  (1 + (N-1)*abs(INCV))
          The vector v as described above.

INCV

          INCV is INTEGER
          The increment between successive elements of v.  INCV must
          not be zero.

TAU

          TAU is COMPLEX
          The value tau as described above.

C

          C is COMPLEX array, dimension (LDC, N)
          On entry, the matrix C.
          On exit, C is overwritten by H * C * H'.

LDC

          LDC is INTEGER
          The leading dimension of the array C.  LDC >= max( 1, N ).

WORK

          WORK is COMPLEX array, dimension (N)

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 107 of file clarfy.f.

DLARFY

Purpose:

 DLARFY applies an elementary reflector, or Householder matrix, H,
 to an n x n symmetric matrix C, from both the left and the right.

 H is represented in the form

    H = I - tau * v * v'

 where  tau  is a scalar and  v  is a vector.

 If  tau  is  zero, then  H  is taken to be the unit matrix.

Parameters

UPLO

          UPLO is CHARACTER*1
          Specifies whether the upper or lower triangular part of the
          symmetric matrix C is stored.
          = 'U':  Upper triangle
          = 'L':  Lower triangle

N

          N is INTEGER
          The number of rows and columns of the matrix C.  N >= 0.

V

          V is DOUBLE PRECISION array, dimension
                  (1 + (N-1)*abs(INCV))
          The vector v as described above.

INCV

          INCV is INTEGER
          The increment between successive elements of v.  INCV must
          not be zero.

TAU

          TAU is DOUBLE PRECISION
          The value tau as described above.

C

          C is DOUBLE PRECISION array, dimension (LDC, N)
          On entry, the matrix C.
          On exit, C is overwritten by H * C * H'.

LDC

          LDC is INTEGER
          The leading dimension of the array C.  LDC >= max( 1, N ).

WORK

          WORK is DOUBLE PRECISION array, dimension (N)

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 107 of file dlarfy.f.

SLARFY

Purpose:

 SLARFY applies an elementary reflector, or Householder matrix, H,
 to an n x n symmetric matrix C, from both the left and the right.

 H is represented in the form

    H = I - tau * v * v'

 where  tau  is a scalar and  v  is a vector.

 If  tau  is  zero, then  H  is taken to be the unit matrix.

Parameters

UPLO

          UPLO is CHARACTER*1
          Specifies whether the upper or lower triangular part of the
          symmetric matrix C is stored.
          = 'U':  Upper triangle
          = 'L':  Lower triangle

N

          N is INTEGER
          The number of rows and columns of the matrix C.  N >= 0.

V

          V is REAL array, dimension
                  (1 + (N-1)*abs(INCV))
          The vector v as described above.

INCV

          INCV is INTEGER
          The increment between successive elements of v.  INCV must
          not be zero.

TAU

          TAU is REAL
          The value tau as described above.

C

          C is REAL array, dimension (LDC, N)
          On entry, the matrix C.
          On exit, C is overwritten by H * C * H'.

LDC

          LDC is INTEGER
          The leading dimension of the array C.  LDC >= max( 1, N ).

WORK

          WORK is REAL array, dimension (N)

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 107 of file slarfy.f.

ZLARFY

Purpose:

 ZLARFY applies an elementary reflector, or Householder matrix, H,
 to an n x n Hermitian matrix C, from both the left and the right.

 H is represented in the form

    H = I - tau * v * v'

 where  tau  is a scalar and  v  is a vector.

 If  tau  is  zero, then  H  is taken to be the unit matrix.

Parameters

UPLO

          UPLO is CHARACTER*1
          Specifies whether the upper or lower triangular part of the
          Hermitian matrix C is stored.
          = 'U':  Upper triangle
          = 'L':  Lower triangle

N

          N is INTEGER
          The number of rows and columns of the matrix C.  N >= 0.

V

          V is COMPLEX*16 array, dimension
                  (1 + (N-1)*abs(INCV))
          The vector v as described above.

INCV

          INCV is INTEGER
          The increment between successive elements of v.  INCV must
          not be zero.

TAU

          TAU is COMPLEX*16
          The value tau as described above.

C

          C is COMPLEX*16 array, dimension (LDC, N)
          On entry, the matrix C.
          On exit, C is overwritten by H * C * H'.

LDC

          LDC is INTEGER
          The leading dimension of the array C.  LDC >= max( 1, N ).

WORK

          WORK is COMPLEX*16 array, dimension (N)

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 107 of file zlarfy.f.