1SLARFX(1) LAPACK auxiliary routine (version 3.2) SLARFX(1)
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6 SLARFX - applies a real elementary reflector H to a real m by n matrix
7 C, from either the left or the right
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10 SUBROUTINE SLARFX( SIDE, M, N, V, TAU, C, LDC, WORK )
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12 CHARACTER SIDE
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14 INTEGER LDC, M, N
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16 REAL TAU
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18 REAL C( LDC, * ), V( * ), WORK( * )
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21 SLARFX applies a real elementary reflector H to a real m by n matrix C,
22 from either the left or the right. H is represented in the form
23 H = I - tau * v * v'
24 where tau is a real scalar and v is a real vector.
25 If tau = 0, then H is taken to be the unit matrix
26 This version uses inline code if H has order < 11.
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29 SIDE (input) CHARACTER*1
30 = 'L': form H * C
31 = 'R': form C * H
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33 M (input) INTEGER
34 The number of rows of the matrix C.
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36 N (input) INTEGER
37 The number of columns of the matrix C.
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39 V (input) REAL array, dimension (M) if SIDE = 'L'
40 or (N) if SIDE = 'R' The vector v in the representation of H.
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42 TAU (input) REAL
43 The value tau in the representation of H.
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45 C (input/output) REAL array, dimension (LDC,N)
46 On entry, the m by n matrix C. On exit, C is overwritten by
47 the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'.
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49 LDC (input) INTEGER
50 The leading dimension of the array C. LDA >= (1,M).
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52 WORK (workspace) REAL array, dimension
53 (N) if SIDE = 'L' or (M) if SIDE = 'R' WORK is not referenced
54 if H has order < 11.
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58 LAPACK auxiliary routine (versionNo3v.e2m)ber 2008 SLARFX(1)