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Diffstat (limited to 'src/lib/lapack/dlarzt.f')
| -rw-r--r-- | src/lib/lapack/dlarzt.f | 184 |
1 files changed, 0 insertions, 184 deletions
diff --git a/src/lib/lapack/dlarzt.f b/src/lib/lapack/dlarzt.f deleted file mode 100644 index d79636e0..00000000 --- a/src/lib/lapack/dlarzt.f +++ /dev/null @@ -1,184 +0,0 @@ - SUBROUTINE DLARZT( DIRECT, STOREV, N, K, V, LDV, TAU, T, LDT ) -* -* -- LAPACK routine (version 3.1) -- -* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. -* November 2006 -* -* .. Scalar Arguments .. - CHARACTER DIRECT, STOREV - INTEGER K, LDT, LDV, N -* .. -* .. Array Arguments .. - DOUBLE PRECISION T( LDT, * ), TAU( * ), V( LDV, * ) -* .. -* -* Purpose -* ======= -* -* DLARZT forms the triangular factor T of a real block reflector -* H of order > n, which is defined as a product of k elementary -* reflectors. -* -* If DIRECT = 'F', H = H(1) H(2) . . . H(k) and T is upper triangular; -* -* If DIRECT = 'B', H = H(k) . . . H(2) H(1) and T is lower triangular. -* -* If STOREV = 'C', the vector which defines the elementary reflector -* H(i) is stored in the i-th column of the array V, and -* -* H = I - V * T * V' -* -* If STOREV = 'R', the vector which defines the elementary reflector -* H(i) is stored in the i-th row of the array V, and -* -* H = I - V' * T * V -* -* Currently, only STOREV = 'R' and DIRECT = 'B' are supported. -* -* Arguments -* ========= -* -* DIRECT (input) CHARACTER*1 -* Specifies the order in which the elementary reflectors are -* multiplied to form the block reflector: -* = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet) -* = 'B': H = H(k) . . . H(2) H(1) (Backward) -* -* STOREV (input) CHARACTER*1 -* Specifies how the vectors which define the elementary -* reflectors are stored (see also Further Details): -* = 'C': columnwise (not supported yet) -* = 'R': rowwise -* -* N (input) INTEGER -* The order of the block reflector H. N >= 0. -* -* K (input) INTEGER -* The order of the triangular factor T (= the number of -* elementary reflectors). K >= 1. -* -* V (input/output) DOUBLE PRECISION array, dimension -* (LDV,K) if STOREV = 'C' -* (LDV,N) if STOREV = 'R' -* The matrix V. See further details. -* -* LDV (input) INTEGER -* The leading dimension of the array V. -* If STOREV = 'C', LDV >= max(1,N); if STOREV = 'R', LDV >= K. -* -* TAU (input) DOUBLE PRECISION array, dimension (K) -* TAU(i) must contain the scalar factor of the elementary -* reflector H(i). -* -* T (output) DOUBLE PRECISION array, dimension (LDT,K) -* The k by k triangular factor T of the block reflector. -* If DIRECT = 'F', T is upper triangular; if DIRECT = 'B', T is -* lower triangular. The rest of the array is not used. -* -* LDT (input) INTEGER -* The leading dimension of the array T. LDT >= K. -* -* Further Details -* =============== -* -* Based on contributions by -* A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA -* -* The shape of the matrix V and the storage of the vectors which define -* the H(i) is best illustrated by the following example with n = 5 and -* k = 3. The elements equal to 1 are not stored; the corresponding -* array elements are modified but restored on exit. The rest of the -* array is not used. -* -* DIRECT = 'F' and STOREV = 'C': DIRECT = 'F' and STOREV = 'R': -* -* ______V_____ -* ( v1 v2 v3 ) / \ -* ( v1 v2 v3 ) ( v1 v1 v1 v1 v1 . . . . 1 ) -* V = ( v1 v2 v3 ) ( v2 v2 v2 v2 v2 . . . 1 ) -* ( v1 v2 v3 ) ( v3 v3 v3 v3 v3 . . 1 ) -* ( v1 v2 v3 ) -* . . . -* . . . -* 1 . . -* 1 . -* 1 -* -* DIRECT = 'B' and STOREV = 'C': DIRECT = 'B' and STOREV = 'R': -* -* ______V_____ -* 1 / \ -* . 1 ( 1 . . . . v1 v1 v1 v1 v1 ) -* . . 1 ( . 1 . . . v2 v2 v2 v2 v2 ) -* . . . ( . . 1 . . v3 v3 v3 v3 v3 ) -* . . . -* ( v1 v2 v3 ) -* ( v1 v2 v3 ) -* V = ( v1 v2 v3 ) -* ( v1 v2 v3 ) -* ( v1 v2 v3 ) -* -* ===================================================================== -* -* .. Parameters .. - DOUBLE PRECISION ZERO - PARAMETER ( ZERO = 0.0D+0 ) -* .. -* .. Local Scalars .. - INTEGER I, INFO, J -* .. -* .. External Subroutines .. - EXTERNAL DGEMV, DTRMV, XERBLA -* .. -* .. External Functions .. - LOGICAL LSAME - EXTERNAL LSAME -* .. -* .. Executable Statements .. -* -* Check for currently supported options -* - INFO = 0 - IF( .NOT.LSAME( DIRECT, 'B' ) ) THEN - INFO = -1 - ELSE IF( .NOT.LSAME( STOREV, 'R' ) ) THEN - INFO = -2 - END IF - IF( INFO.NE.0 ) THEN - CALL XERBLA( 'DLARZT', -INFO ) - RETURN - END IF -* - DO 20 I = K, 1, -1 - IF( TAU( I ).EQ.ZERO ) THEN -* -* H(i) = I -* - DO 10 J = I, K - T( J, I ) = ZERO - 10 CONTINUE - ELSE -* -* general case -* - IF( I.LT.K ) THEN -* -* T(i+1:k,i) = - tau(i) * V(i+1:k,1:n) * V(i,1:n)' -* - CALL DGEMV( 'No transpose', K-I, N, -TAU( I ), - $ V( I+1, 1 ), LDV, V( I, 1 ), LDV, ZERO, - $ T( I+1, I ), 1 ) -* -* T(i+1:k,i) = T(i+1:k,i+1:k) * T(i+1:k,i) -* - CALL DTRMV( 'Lower', 'No transpose', 'Non-unit', K-I, - $ T( I+1, I+1 ), LDT, T( I+1, I ), 1 ) - END IF - T( I, I ) = TAU( I ) - END IF - 20 CONTINUE - RETURN -* -* End of DLARZT -* - END |