--- rpl/lapack/lapack/dtftri.f 2010/08/13 21:03:59 1.3 +++ rpl/lapack/lapack/dtftri.f 2023/08/07 08:39:12 1.16 @@ -1,10 +1,205 @@ - SUBROUTINE DTFTRI( TRANSR, UPLO, DIAG, N, A, INFO ) +*> \brief \b DTFTRI +* +* =========== DOCUMENTATION =========== * -* -- LAPACK routine (version 3.2.2) -- +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ * -* -- Contributed by Fred Gustavson of the IBM Watson Research Center -- -* -- June 2010 -- +*> \htmlonly +*> Download DTFTRI + dependencies +*> +*> [TGZ] +*> +*> [ZIP] +*> +*> [TXT] +*> \endhtmlonly +* +* Definition: +* =========== +* +* SUBROUTINE DTFTRI( TRANSR, UPLO, DIAG, N, A, INFO ) +* +* .. Scalar Arguments .. +* CHARACTER TRANSR, UPLO, DIAG +* INTEGER INFO, N +* .. +* .. Array Arguments .. +* DOUBLE PRECISION A( 0: * ) +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> DTFTRI computes the inverse of a triangular matrix A stored in RFP +*> format. +*> +*> This is a Level 3 BLAS version of the algorithm. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] TRANSR +*> \verbatim +*> TRANSR is CHARACTER*1 +*> = 'N': The Normal TRANSR of RFP A is stored; +*> = 'T': The Transpose TRANSR of RFP A is stored. +*> \endverbatim +*> +*> \param[in] UPLO +*> \verbatim +*> UPLO is CHARACTER*1 +*> = 'U': A is upper triangular; +*> = 'L': A is lower triangular. +*> \endverbatim +*> +*> \param[in] DIAG +*> \verbatim +*> DIAG is CHARACTER*1 +*> = 'N': A is non-unit triangular; +*> = 'U': A is unit triangular. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The order of the matrix A. N >= 0. +*> \endverbatim +*> +*> \param[in,out] A +*> \verbatim +*> A is DOUBLE PRECISION array, dimension (0:nt-1); +*> nt=N*(N+1)/2. On entry, the triangular factor of a Hermitian +*> Positive Definite matrix A in RFP format. RFP format is +*> described by TRANSR, UPLO, and N as follows: If TRANSR = 'N' +*> then RFP A is (0:N,0:k-1) when N is even; k=N/2. RFP A is +*> (0:N-1,0:k) when N is odd; k=N/2. IF TRANSR = 'T' then RFP is +*> the transpose of RFP A as defined when +*> TRANSR = 'N'. The contents of RFP A are defined by UPLO as +*> follows: If UPLO = 'U' the RFP A contains the nt elements of +*> upper packed A; If UPLO = 'L' the RFP A contains the nt +*> elements of lower packed A. The LDA of RFP A is (N+1)/2 when +*> TRANSR = 'T'. When TRANSR is 'N' the LDA is N+1 when N is +*> even and N is odd. See the Note below for more details. +*> +*> On exit, the (triangular) inverse of the original matrix, in +*> the same storage format. +*> \endverbatim +*> +*> \param[out] INFO +*> \verbatim +*> INFO is INTEGER +*> = 0: successful exit +*> < 0: if INFO = -i, the i-th argument had an illegal value +*> > 0: if INFO = i, A(i,i) is exactly zero. The triangular +*> matrix is singular and its inverse can not be computed. +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \ingroup doubleOTHERcomputational +* +*> \par Further Details: +* ===================== +*> +*> \verbatim +*> +*> We first consider Rectangular Full Packed (RFP) Format when N is +*> even. We give an example where N = 6. +*> +*> AP is Upper AP is Lower +*> +*> 00 01 02 03 04 05 00 +*> 11 12 13 14 15 10 11 +*> 22 23 24 25 20 21 22 +*> 33 34 35 30 31 32 33 +*> 44 45 40 41 42 43 44 +*> 55 50 51 52 53 54 55 +*> +*> +*> Let TRANSR = 'N'. RFP holds AP as follows: +*> For UPLO = 'U' the upper trapezoid A(0:5,0:2) consists of the last +*> three columns of AP upper. The lower triangle A(4:6,0:2) consists of +*> the transpose of the first three columns of AP upper. +*> For UPLO = 'L' the lower trapezoid A(1:6,0:2) consists of the first +*> three columns of AP lower. The upper triangle A(0:2,0:2) consists of +*> the transpose of the last three columns of AP lower. +*> This covers the case N even and TRANSR = 'N'. +*> +*> RFP A RFP A +*> +*> 03 04 05 33 43 53 +*> 13 14 15 00 44 54 +*> 23 24 25 10 11 55 +*> 33 34 35 20 21 22 +*> 00 44 45 30 31 32 +*> 01 11 55 40 41 42 +*> 02 12 22 50 51 52 +*> +*> Now let TRANSR = 'T'. RFP A in both UPLO cases is just the +*> transpose of RFP A above. One therefore gets: +*> +*> +*> RFP A RFP A +*> +*> 03 13 23 33 00 01 02 33 00 10 20 30 40 50 +*> 04 14 24 34 44 11 12 43 44 11 21 31 41 51 +*> 05 15 25 35 45 55 22 53 54 55 22 32 42 52 +*> +*> +*> We then consider Rectangular Full Packed (RFP) Format when N is +*> odd. We give an example where N = 5. +*> +*> AP is Upper AP is Lower +*> +*> 00 01 02 03 04 00 +*> 11 12 13 14 10 11 +*> 22 23 24 20 21 22 +*> 33 34 30 31 32 33 +*> 44 40 41 42 43 44 +*> +*> +*> Let TRANSR = 'N'. RFP holds AP as follows: +*> For UPLO = 'U' the upper trapezoid A(0:4,0:2) consists of the last +*> three columns of AP upper. The lower triangle A(3:4,0:1) consists of +*> the transpose of the first two columns of AP upper. +*> For UPLO = 'L' the lower trapezoid A(0:4,0:2) consists of the first +*> three columns of AP lower. The upper triangle A(0:1,1:2) consists of +*> the transpose of the last two columns of AP lower. +*> This covers the case N odd and TRANSR = 'N'. +*> +*> RFP A RFP A +*> +*> 02 03 04 00 33 43 +*> 12 13 14 10 11 44 +*> 22 23 24 20 21 22 +*> 00 33 34 30 31 32 +*> 01 11 44 40 41 42 +*> +*> Now let TRANSR = 'T'. RFP A in both UPLO cases is just the +*> transpose of RFP A above. One therefore gets: +*> +*> RFP A RFP A +*> +*> 02 12 22 00 01 00 10 20 30 40 50 +*> 03 13 23 33 11 33 11 21 31 41 51 +*> 04 14 24 34 44 43 44 22 32 42 52 +*> \endverbatim +*> +* ===================================================================== + SUBROUTINE DTFTRI( TRANSR, UPLO, DIAG, N, A, INFO ) * +* -- LAPACK computational routine -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- * @@ -16,139 +211,6 @@ DOUBLE PRECISION A( 0: * ) * .. * -* Purpose -* ======= -* -* DTFTRI computes the inverse of a triangular matrix A stored in RFP -* format. -* -* This is a Level 3 BLAS version of the algorithm. -* -* Arguments -* ========= -* -* TRANSR (input) CHARACTER -* = 'N': The Normal TRANSR of RFP A is stored; -* = 'T': The Transpose TRANSR of RFP A is stored. -* -* UPLO (input) CHARACTER -* = 'U': A is upper triangular; -* = 'L': A is lower triangular. -* -* DIAG (input) CHARACTER -* = 'N': A is non-unit triangular; -* = 'U': A is unit triangular. -* -* N (input) INTEGER -* The order of the matrix A. N >= 0. -* -* A (input/output) DOUBLE PRECISION array, dimension (0:nt-1); -* nt=N*(N+1)/2. On entry, the triangular factor of a Hermitian -* Positive Definite matrix A in RFP format. RFP format is -* described by TRANSR, UPLO, and N as follows: If TRANSR = 'N' -* then RFP A is (0:N,0:k-1) when N is even; k=N/2. RFP A is -* (0:N-1,0:k) when N is odd; k=N/2. IF TRANSR = 'T' then RFP is -* the transpose of RFP A as defined when -* TRANSR = 'N'. The contents of RFP A are defined by UPLO as -* follows: If UPLO = 'U' the RFP A contains the nt elements of -* upper packed A; If UPLO = 'L' the RFP A contains the nt -* elements of lower packed A. The LDA of RFP A is (N+1)/2 when -* TRANSR = 'T'. When TRANSR is 'N' the LDA is N+1 when N is -* even and N is odd. See the Note below for more details. -* -* On exit, the (triangular) inverse of the original matrix, in -* the same storage format. -* -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -i, the i-th argument had an illegal value -* > 0: if INFO = i, A(i,i) is exactly zero. The triangular -* matrix is singular and its inverse can not be computed. -* -* Further Details -* =============== -* -* We first consider Rectangular Full Packed (RFP) Format when N is -* even. We give an example where N = 6. -* -* AP is Upper AP is Lower -* -* 00 01 02 03 04 05 00 -* 11 12 13 14 15 10 11 -* 22 23 24 25 20 21 22 -* 33 34 35 30 31 32 33 -* 44 45 40 41 42 43 44 -* 55 50 51 52 53 54 55 -* -* -* Let TRANSR = 'N'. RFP holds AP as follows: -* For UPLO = 'U' the upper trapezoid A(0:5,0:2) consists of the last -* three columns of AP upper. The lower triangle A(4:6,0:2) consists of -* the transpose of the first three columns of AP upper. -* For UPLO = 'L' the lower trapezoid A(1:6,0:2) consists of the first -* three columns of AP lower. The upper triangle A(0:2,0:2) consists of -* the transpose of the last three columns of AP lower. -* This covers the case N even and TRANSR = 'N'. -* -* RFP A RFP A -* -* 03 04 05 33 43 53 -* 13 14 15 00 44 54 -* 23 24 25 10 11 55 -* 33 34 35 20 21 22 -* 00 44 45 30 31 32 -* 01 11 55 40 41 42 -* 02 12 22 50 51 52 -* -* Now let TRANSR = 'T'. RFP A in both UPLO cases is just the -* transpose of RFP A above. One therefore gets: -* -* -* RFP A RFP A -* -* 03 13 23 33 00 01 02 33 00 10 20 30 40 50 -* 04 14 24 34 44 11 12 43 44 11 21 31 41 51 -* 05 15 25 35 45 55 22 53 54 55 22 32 42 52 -* -* -* We then consider Rectangular Full Packed (RFP) Format when N is -* odd. We give an example where N = 5. -* -* AP is Upper AP is Lower -* -* 00 01 02 03 04 00 -* 11 12 13 14 10 11 -* 22 23 24 20 21 22 -* 33 34 30 31 32 33 -* 44 40 41 42 43 44 -* -* -* Let TRANSR = 'N'. RFP holds AP as follows: -* For UPLO = 'U' the upper trapezoid A(0:4,0:2) consists of the last -* three columns of AP upper. The lower triangle A(3:4,0:1) consists of -* the transpose of the first two columns of AP upper. -* For UPLO = 'L' the lower trapezoid A(0:4,0:2) consists of the first -* three columns of AP lower. The upper triangle A(0:1,1:2) consists of -* the transpose of the last two columns of AP lower. -* This covers the case N odd and TRANSR = 'N'. -* -* RFP A RFP A -* -* 02 03 04 00 33 43 -* 12 13 14 10 11 44 -* 22 23 24 20 21 22 -* 00 33 34 30 31 32 -* 01 11 44 40 41 42 -* -* Now let TRANSR = 'T'. RFP A in both UPLO cases is just the -* transpose of RFP A above. One therefore gets: -* -* RFP A RFP A -* -* 02 12 22 00 01 00 10 20 30 40 50 -* 03 13 23 33 11 33 11 21 31 41 51 -* 04 14 24 34 44 43 44 22 32 42 52 -* * ===================================================================== * * .. Parameters .. @@ -181,7 +243,7 @@ ELSE IF( .NOT.LOWER .AND. .NOT.LSAME( UPLO, 'U' ) ) THEN INFO = -2 ELSE IF( .NOT.LSAME( DIAG, 'N' ) .AND. .NOT.LSAME( DIAG, 'U' ) ) - + THEN + $ THEN INFO = -3 ELSE IF( N.LT.0 ) THEN INFO = -4 @@ -194,7 +256,7 @@ * Quick return if possible * IF( N.EQ.0 ) - + RETURN + $ RETURN * * If N is odd, set NISODD = .TRUE. * If N is even, set K = N/2 and NISODD = .FALSE. @@ -235,16 +297,16 @@ * CALL DTRTRI( 'L', DIAG, N1, A( 0 ), N, INFO ) IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'R', 'L', 'N', DIAG, N2, N1, -ONE, A( 0 ), - + N, A( N1 ), N ) + $ N, A( N1 ), N ) CALL DTRTRI( 'U', DIAG, N2, A( N ), N, INFO ) IF( INFO.GT.0 ) - + INFO = INFO + N1 + $ INFO = INFO + N1 IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'L', 'U', 'T', DIAG, N2, N1, ONE, A( N ), N, - + A( N1 ), N ) + $ A( N1 ), N ) * ELSE * @@ -254,16 +316,16 @@ * CALL DTRTRI( 'L', DIAG, N1, A( N2 ), N, INFO ) IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'L', 'L', 'T', DIAG, N1, N2, -ONE, A( N2 ), - + N, A( 0 ), N ) + $ N, A( 0 ), N ) CALL DTRTRI( 'U', DIAG, N2, A( N1 ), N, INFO ) IF( INFO.GT.0 ) - + INFO = INFO + N1 + $ INFO = INFO + N1 IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'R', 'U', 'N', DIAG, N1, N2, ONE, A( N1 ), - + N, A( 0 ), N ) + $ N, A( 0 ), N ) * END IF * @@ -278,16 +340,16 @@ * CALL DTRTRI( 'U', DIAG, N1, A( 0 ), N1, INFO ) IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'L', 'U', 'N', DIAG, N1, N2, -ONE, A( 0 ), - + N1, A( N1*N1 ), N1 ) + $ N1, A( N1*N1 ), N1 ) CALL DTRTRI( 'L', DIAG, N2, A( 1 ), N1, INFO ) IF( INFO.GT.0 ) - + INFO = INFO + N1 + $ INFO = INFO + N1 IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'R', 'L', 'T', DIAG, N1, N2, ONE, A( 1 ), - + N1, A( N1*N1 ), N1 ) + $ N1, A( N1*N1 ), N1 ) * ELSE * @@ -296,16 +358,16 @@ * CALL DTRTRI( 'U', DIAG, N1, A( N2*N2 ), N2, INFO ) IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'R', 'U', 'T', DIAG, N2, N1, -ONE, - + A( N2*N2 ), N2, A( 0 ), N2 ) + $ A( N2*N2 ), N2, A( 0 ), N2 ) CALL DTRTRI( 'L', DIAG, N2, A( N1*N2 ), N2, INFO ) IF( INFO.GT.0 ) - + INFO = INFO + N1 + $ INFO = INFO + N1 IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'L', 'L', 'N', DIAG, N2, N1, ONE, - + A( N1*N2 ), N2, A( 0 ), N2 ) + $ A( N1*N2 ), N2, A( 0 ), N2 ) END IF * END IF @@ -326,16 +388,16 @@ * CALL DTRTRI( 'L', DIAG, K, A( 1 ), N+1, INFO ) IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'R', 'L', 'N', DIAG, K, K, -ONE, A( 1 ), - + N+1, A( K+1 ), N+1 ) + $ N+1, A( K+1 ), N+1 ) CALL DTRTRI( 'U', DIAG, K, A( 0 ), N+1, INFO ) IF( INFO.GT.0 ) - + INFO = INFO + K + $ INFO = INFO + K IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'L', 'U', 'T', DIAG, K, K, ONE, A( 0 ), N+1, - + A( K+1 ), N+1 ) + $ A( K+1 ), N+1 ) * ELSE * @@ -345,16 +407,16 @@ * CALL DTRTRI( 'L', DIAG, K, A( K+1 ), N+1, INFO ) IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'L', 'L', 'T', DIAG, K, K, -ONE, A( K+1 ), - + N+1, A( 0 ), N+1 ) + $ N+1, A( 0 ), N+1 ) CALL DTRTRI( 'U', DIAG, K, A( K ), N+1, INFO ) IF( INFO.GT.0 ) - + INFO = INFO + K + $ INFO = INFO + K IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'R', 'U', 'N', DIAG, K, K, ONE, A( K ), N+1, - + A( 0 ), N+1 ) + $ A( 0 ), N+1 ) END IF ELSE * @@ -368,16 +430,16 @@ * CALL DTRTRI( 'U', DIAG, K, A( K ), K, INFO ) IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'L', 'U', 'N', DIAG, K, K, -ONE, A( K ), K, - + A( K*( K+1 ) ), K ) + $ A( K*( K+1 ) ), K ) CALL DTRTRI( 'L', DIAG, K, A( 0 ), K, INFO ) IF( INFO.GT.0 ) - + INFO = INFO + K + $ INFO = INFO + K IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'R', 'L', 'T', DIAG, K, K, ONE, A( 0 ), K, - + A( K*( K+1 ) ), K ) + $ A( K*( K+1 ) ), K ) ELSE * * SRPA for UPPER, TRANSPOSE and N is even (see paper) @@ -386,16 +448,16 @@ * CALL DTRTRI( 'U', DIAG, K, A( K*( K+1 ) ), K, INFO ) IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'R', 'U', 'T', DIAG, K, K, -ONE, - + A( K*( K+1 ) ), K, A( 0 ), K ) + $ A( K*( K+1 ) ), K, A( 0 ), K ) CALL DTRTRI( 'L', DIAG, K, A( K*K ), K, INFO ) IF( INFO.GT.0 ) - + INFO = INFO + K + $ INFO = INFO + K IF( INFO.GT.0 ) - + RETURN + $ RETURN CALL DTRMM( 'L', 'L', 'N', DIAG, K, K, ONE, A( K*K ), K, - + A( 0 ), K ) + $ A( 0 ), K ) END IF END IF END IF