larfx - larfx: apply Householder reflector, unrolled

Generated automatically by Doxygen for LAPACK from the source code. Version 3.12.0 Sun Jul 20 2025 01:40:05 larfx(3)

subroutineclarfx(characterside,integerm,integern,complex,dimension(*)v,complextau,complex,dimension(ldc,*)c,integerldc,complex,dimension(*)work)CLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10. Purpose: CLARFX applies a complex elementary reflector H to a complex m by n matrix C, from either the left or the right. H is represented in the form H = I - tau * v * v**H where tau is a complex scalar and v is a complex vector. If tau = 0, then H is taken to be the unit matrix This version uses inline code if H has order < 11. ParametersSIDE SIDE is CHARACTER*1 = 'L': form H * C = 'R': form C * H M M is INTEGER The number of rows of the matrix C. N N is INTEGER The number of columns of the matrix C. V V is COMPLEX array, dimension (M) if SIDE = 'L' or (N) if SIDE = 'R' The vector v in the representation of H. TAU TAU is COMPLEX The value tau in the representation of H. C C is COMPLEX array, dimension (LDC,N) On entry, the m by n matrix C. On exit, C is overwritten by the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'. LDC LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK WORK is COMPLEX array, dimension (N) if SIDE = 'L' or (M) if SIDE = 'R' WORK is not referenced if H has order < 11. Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutinedlarfx(characterside,integerm,integern,doubleprecision,dimension(*)v,doubleprecisiontau,doubleprecision,dimension(ldc,*)c,integerldc,doubleprecision,dimension(*)work)DLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10. Purpose: DLARFX applies a real elementary reflector H to a real m by n matrix C, from either the left or the right. H is represented in the form H = I - tau * v * v**T where tau is a real scalar and v is a real vector. If tau = 0, then H is taken to be the unit matrix This version uses inline code if H has order < 11. ParametersSIDE SIDE is CHARACTER*1 = 'L': form H * C = 'R': form C * H M M is INTEGER The number of rows of the matrix C. N N is INTEGER The number of columns of the matrix C. V V is DOUBLE PRECISION array, dimension (M) if SIDE = 'L' or (N) if SIDE = 'R' The vector v in the representation of H. TAU TAU is DOUBLE PRECISION The value tau in the representation of H. C C is DOUBLE PRECISION array, dimension (LDC,N) On entry, the m by n matrix C. On exit, C is overwritten by the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'. LDC LDC is INTEGER The leading dimension of the array C. LDC >= (1,M). WORK WORK is DOUBLE PRECISION array, dimension (N) if SIDE = 'L' or (M) if SIDE = 'R' WORK is not referenced if H has order < 11. Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutineslarfx(characterside,integerm,integern,real,dimension(*)v,realtau,real,dimension(ldc,*)c,integerldc,real,dimension(*)work)SLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10. Purpose: SLARFX applies a real elementary reflector H to a real m by n matrix C, from either the left or the right. H is represented in the form H = I - tau * v * v**T where tau is a real scalar and v is a real vector. If tau = 0, then H is taken to be the unit matrix This version uses inline code if H has order < 11. ParametersSIDE SIDE is CHARACTER*1 = 'L': form H * C = 'R': form C * H M M is INTEGER The number of rows of the matrix C. N N is INTEGER The number of columns of the matrix C. V V is REAL array, dimension (M) if SIDE = 'L' or (N) if SIDE = 'R' The vector v in the representation of H. TAU TAU is REAL The value tau in the representation of H. C C is REAL array, dimension (LDC,N) On entry, the m by n matrix C. On exit, C is overwritten by the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'. LDC LDC is INTEGER The leading dimension of the array C. LDC >= (1,M). WORK WORK is REAL array, dimension (N) if SIDE = 'L' or (M) if SIDE = 'R' WORK is not referenced if H has order < 11. Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutinezlarfx(characterside,integerm,integern,complex*16,dimension(*)v,complex*16tau,complex*16,dimension(ldc,*)c,integerldc,complex*16,dimension(*)work)ZLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10. Purpose: ZLARFX applies a complex elementary reflector H to a complex m by n matrix C, from either the left or the right. H is represented in the form H = I - tau * v * v**H where tau is a complex scalar and v is a complex vector. If tau = 0, then H is taken to be the unit matrix This version uses inline code if H has order < 11. ParametersSIDE SIDE is CHARACTER*1 = 'L': form H * C = 'R': form C * H M M is INTEGER The number of rows of the matrix C. N N is INTEGER The number of columns of the matrix C. V V is COMPLEX*16 array, dimension (M) if SIDE = 'L' or (N) if SIDE = 'R' The vector v in the representation of H. TAU TAU is COMPLEX*16 The value tau in the representation of H. C C is COMPLEX*16 array, dimension (LDC,N) On entry, the m by n matrix C. On exit, C is overwritten by the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'. LDC LDC is INTEGER The leading dimension of the array C. LDC >= max(1,M). WORK WORK is COMPLEX*16 array, dimension (N) if SIDE = 'L' or (M) if SIDE = 'R' WORK is not referenced if H has order < 11. Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.

larfx - larfx: apply Householder reflector, unrolled

Functions subroutine clarfx (side, m, n, v, tau, c, ldc, work) CLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10. subroutine dlarfx (side, m, n, v, tau, c, ldc, work) DLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10. subroutine slarfx (side, m, n, v, tau, c, ldc, work) SLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10. subroutine zlarfx (side, m, n, v, tau, c, ldc, work) ZLARFX applies an elementary reflector to a general rectangular matrix, with loop unrolling when the reflector has order ≤ 10.