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📄 inverse.f

📁 一个基于打靶法的最优控制求解软件 求解过程中采用参数延续算法
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               END IF            END IF   20    CONTINUE      END IF      RETURN**     End of DGETRF*      END      SUBROUTINE DGETRI( N, A, LDA, IPIV, WORK, LWORK, INFO )**  -- LAPACK routine (version 3.0) --*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,*     Courant Institute, Argonne National Lab, and Rice University*     June 30, 1999**     .. Scalar Arguments ..      INTEGER            INFO, LDA, LWORK, N*     ..*     .. Array Arguments ..      INTEGER            IPIV( * )      DOUBLE PRECISION   A( LDA, * ), WORK( * )*     ..**  Purpose*  =======**  DGETRI computes the inverse of a matrix using the LU factorization*  computed by DGETRF.**  This method inverts U and then computes inv(A) by solving the system*  inv(A)*L = inv(U) for inv(A).**  Arguments*  =========**  N       (input) INTEGER*          The order of the matrix A.  N >= 0.**  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)*          On entry, the factors L and U from the factorization*          A = P*L*U as computed by DGETRF.*          On exit, if INFO = 0, the inverse of the original matrix A.**  LDA     (input) INTEGER*          The leading dimension of the array A.  LDA >= max(1,N).**  IPIV    (input) INTEGER array, dimension (N)*          The pivot indices from DGETRF; for 1<=i<=N, row i of the*          matrix was interchanged with row IPIV(i).**  WORK    (workspace/output) DOUBLE PRECISION array, dimension (LWORK)*          On exit, if INFO=0, then WORK(1) returns the optimal LWORK.**  LWORK   (input) INTEGER*          The dimension of the array WORK.  LWORK >= max(1,N).*          For optimal performance LWORK >= N*NB, where NB is*          the optimal blocksize returned by ILAENV.**          If LWORK = -1, then a workspace query is assumed; the routine*          only calculates the optimal size of the WORK array, returns*          this value as the first entry of the WORK array, and no error*          message related to LWORK is issued by XERBLA.**  INFO    (output) INTEGER*          = 0:  successful exit*          < 0:  if INFO = -i, the i-th argument had an illegal value*          > 0:  if INFO = i, U(i,i) is exactly zero; the matrix is*                singular and its inverse could not be computed.**  =====================================================================**     .. Parameters ..      DOUBLE PRECISION   ZERO, ONE      PARAMETER          ( ZERO = 0D+0, ONE = 1D+0 )*     ..*     .. Local Scalars ..      LOGICAL            LQUERY      INTEGER            I, IWS, J, JB, JJ, JP, LDWORK, LWKOPT, NB,     $                   NBMIN, NN*     ..*     .. External Functions ..      INTEGER            ILAENV      EXTERNAL           ILAENV*     ..*     .. External Subroutines ..      EXTERNAL           DGEMM, DGEMV, DSWAP, DTRSM, DTRTRI, XERBLA*     ..*     .. Intrinsic Functions ..      INTRINSIC          MAX, MIN*     ..*     .. Executable Statements ..**     Test the input parameters.*      INFO = 0      NB = ILAENV( 1, 'DGETRI', ' ', N, -1, -1, -1 )      LWKOPT = N*NB      WORK( 1 ) = LWKOPT      LQUERY = ( LWORK.EQ.-1 )      IF( N.LT.0 ) THEN         INFO = -1      ELSE IF( LDA.LT.MAX( 1, N ) ) THEN         INFO = -3      ELSE IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN         INFO = -6      END IF      IF( INFO.NE.0 ) THEN         CALL XERBLA( 'DGETRI', -INFO )         RETURN      ELSE IF( LQUERY ) THEN         RETURN      END IF**     Quick return if possible*      IF( N.EQ.0 )     $   RETURN**     Form inv(U).  If INFO > 0 from DTRTRI, then U is singular,*     and the inverse is not computed.*      CALL DTRTRI( 'Upper', 'Non-unit', N, A, LDA, INFO )      IF( INFO.GT.0 )     $   RETURN*      NBMIN = 2      LDWORK = N      IF( NB.GT.1 .AND. NB.LT.N ) THEN         IWS = MAX( LDWORK*NB, 1 )         IF( LWORK.LT.IWS ) THEN            NB = LWORK / LDWORK            NBMIN = MAX( 2, ILAENV( 2, 'DGETRI', ' ', N, -1, -1, -1 ) )         END IF      ELSE         IWS = N      END IF**     Solve the equation inv(A)*L = inv(U) for inv(A).*      IF( NB.LT.NBMIN .OR. NB.GE.N ) THEN**        Use unblocked code.*         DO 20 J = N, 1, -1**           Copy current column of L to WORK and replace with zeros.*            DO 10 I = J + 1, N               WORK( I ) = A( I, J )               A( I, J ) = ZERO   10       CONTINUE**           Compute current column of inv(A).*            IF( J.LT.N )     $         CALL DGEMV( 'No transpose', N, N-J, -ONE, A( 1, J+1 ),     $                     LDA, WORK( J+1 ), 1, ONE, A( 1, J ), 1 )   20    CONTINUE      ELSE**        Use blocked code.*         NN = ( ( N-1 ) / NB )*NB + 1         DO 50 J = NN, 1, -NB            JB = MIN( NB, N-J+1 )**           Copy current block column of L to WORK and replace with*           zeros.*            DO 40 JJ = J, J + JB - 1               DO 30 I = JJ + 1, N                  WORK( I+( JJ-J )*LDWORK ) = A( I, JJ )                  A( I, JJ ) = ZERO   30          CONTINUE   40       CONTINUE**           Compute current block column of inv(A).*            IF( J+JB.LE.N )     $         CALL DGEMM( 'No transpose', 'No transpose', N, JB,     $                     N-J-JB+1, -ONE, A( 1, J+JB ), LDA,     $                     WORK( J+JB ), LDWORK, ONE, A( 1, J ), LDA )            CALL DTRSM( 'Right', 'Lower', 'No transpose', 'Unit', N, JB,     $                  ONE, WORK( J ), LDWORK, A( 1, J ), LDA )   50    CONTINUE      END IF**     Apply column interchanges.*      DO 60 J = N - 1, 1, -1         JP = IPIV( J )         IF( JP.NE.J )     $      CALL DSWAP( N, A( 1, J ), 1, A( 1, JP ), 1 )   60 CONTINUE*      WORK( 1 ) = IWS      RETURN**     End of DGETRI*      END      SUBROUTINE DGETRS( TRANS, N, NRHS, A, LDA, IPIV, B, LDB, INFO )**  -- LAPACK routine (version 1.0) --*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,*     Courant Institute, Argonne National Lab, and Rice University*     February 29, 1992**     .. Scalar Arguments ..      CHARACTER          TRANS      INTEGER            INFO, LDA, LDB, N, NRHS*     ..*     .. Array Arguments ..      INTEGER            IPIV( * )      DOUBLE PRECISION   A( LDA, * ), B( LDB, * )*     ..**  Purpose*  =======**  DGETRS solves a system of linear equations*     A * X = B  or  A' * X = B*  with a general n by n matrix A using the LU factorization computed*  by DGETRF.**  Arguments*  =========**  TRANS   (input) CHARACTER*1*          Specifies the form of the system of equations.*          = 'N':  A * X = B  (No transpose)*          = 'T':  A'* X = B  (Transpose)*          = 'C':  A'* X = B  (Conjugate transpose = Transpose)**  N       (input) INTEGER*          The order of the matrix A.  N >= 0.**  NRHS    (input) INTEGER*          The number of right hand sides, i.e., the number of columns*          of the matrix B.  NRHS >= 0.**  A       (input) DOUBLE PRECISION array, dimension (LDA,N)*          The factors L and U from the factorization A = P*L*U*          as computed by DGETRF.**  LDA     (input) INTEGER*          The leading dimension of the array A.  LDA >= max(1,N).**  IPIV    (input) INTEGER array, dimension (N)*          The pivot indices from DGETRF; for 1<=i<=N, row i of the*          matrix was interchanged with row IPIV(i).**  B       (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)*          On entry, the right hand side vectors B for the system of*          linear equations.*          On exit, the solution vectors, X.**  LDB     (input) INTEGER*          The leading dimension of the array B.  LDB >= max(1,N).**  INFO    (output) INTEGER*          = 0:  successful exit*          < 0: if INFO = -k, the k-th argument had an illegal value**  =====================================================================**     .. Parameters ..      DOUBLE PRECISION   ONE      PARAMETER          ( ONE = 1D+0 )*     ..*     .. Local Scalars ..      LOGICAL            NOTRAN*     ..*     .. External Functions ..      LOGICAL            LSAME      EXTERNAL           LSAME*     ..*     .. External Subroutines ..      EXTERNAL           DLASWP, DTRSM, XERBLA*     ..*     .. Intrinsic Functions ..      INTRINSIC          MAX*     ..*     .. Executable Statements ..**     Test the input parameters.*      INFO = 0      NOTRAN = LSAME( TRANS, 'N' )      IF( .NOT.NOTRAN .AND. .NOT.LSAME( TRANS, 'T' ) .AND. .NOT.     $    LSAME( TRANS, 'C' ) ) THEN         INFO = -1      ELSE IF( N.LT.0 ) THEN         INFO = -2      ELSE IF( NRHS.LT.0 ) THEN         INFO = -3      ELSE IF( LDA.LT.MAX( 1, N ) ) THEN         INFO = -5      ELSE IF( LDB.LT.MAX( 1, N ) ) THEN         INFO = -8      END IF      IF( INFO.NE.0 ) THEN         CALL XERBLA( 'DGETRS', -INFO )         RETURN      END IF**     Quick return if possible*      IF( N.EQ.0 .OR. NRHS.EQ.0 )     $   RETURN*      IF( NOTRAN ) THEN**        Solve A * X = B.**        Apply row interchanges to the right hand sides.*         CALL DLASWP( NRHS, B, LDB, 1, N, IPIV, 1 )**        Solve L*X = B, overwriting B with X.*         CALL DTRSM( 'Left', 'Lower', 'No transpose', 'Unit', N, NRHS,     $               ONE, A, LDA, B, LDB )**        Solve U*X = B, overwriting B with X.*         CALL DTRSM( 'Left', 'Upper', 'No transpose', 'Non-unit', N,     $               NRHS, ONE, A, LDA, B, LDB )      ELSE**        Solve A' * X = B.**        Solve U'*X = B, overwriting B with X.*         CALL DTRSM( 'Left', 'Upper', 'Transpose', 'Non-unit', N, NRHS,     $               ONE, A, LDA, B, LDB )**        Solve L'*X = B, overwriting B with X.*         CALL DTRSM( 'Left', 'Lower', 'Transpose', 'Unit', N, NRHS, ONE,     $               A, LDA, B, LDB )**        Apply row interchanges to the solution vectors.*         CALL DLASWP( NRHS, B, LDB, 1, N, IPIV, -1 )      END IF*      RETURN**     End of DGETRS*      END      SUBROUTINE DLASWP( N, A, LDA, K1, K2, IPIV, INCX )**  -- LAPACK auxiliary routine (version 1.0) --*     Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,*     Courant Institute, Argonne National Lab, and Rice University*     February 29, 1992**     .. Scalar Arguments ..      INTEGER            INCX, K1, K2, LDA, N*     ..*     .. Array Arguments ..      INTEGER            IPIV( * )      DOUBLE PRECISION   A( LDA, * )*     ..**  Purpose*  =======**  DLASWP performs a series of row interchanges on the matrix A.*  One row interchange is initiated for each of rows K1 through K2 of A.**  Arguments*  =========**  N       (input) INTEGER*          The number of columns of the matrix A.**  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)*          On entry, the matrix of column dimension N to which the row*          interchanges will be applied.*          On exit, the permuted matrix.**  LDA     (input) INTEGER*          The leading dimension of the array A.**  K1      (input) INTEGER*          The first element of IPIV for which a row interchange will*          be done.**  K2      (input) INTEGER*          The last element of IPIV for which a row interchange will*          be done.**  IPIV    (input) INTEGER array, dimension (M*abs(INCX))*          The vector of pivot indices.  Only the elements in positions*          K1 through K2 of IPIV are accessed.*          IPIV(K) = L implies rows K and L are to be interchanged.**  INCX    (input) INTEGER*          The increment between successive values of IPIV.  If IPIV*          is negative, the pivots are applied in reverse order.***     .. Local Scalars ..      INTEGER            I, IP, IX*     ..*     .. External Subroutines ..      EXTERNAL           DSWAP*     ..*     .. Executable Statements ..**     Interchange row I with row IPIV(I) for each of rows K1 through K2.*      IF( INCX.EQ.0 )     $   RETURN      IF( INCX.GT.0 ) THEN         IX = K1      ELSE         IX = 1 + ( 1-K2 )*INCX      END IF      IF( INCX.EQ.1 ) THEN         DO 10 I = K1, K2            IP = IPIV( I )            IF( IP.NE.I )     $         CALL DSWAP( N, A( I, 1 ), LDA, A( IP, 1 ), LDA )   10    CONTINUE      ELSE IF( INCX.GT.1 ) THEN         DO 20 I = K1, K2            IP = IPIV( IX )            IF( IP.NE.I )

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