diff options
Diffstat (limited to 'src/lib/lapack/dtrtri.f')
| -rw-r--r-- | src/lib/lapack/dtrtri.f | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/src/lib/lapack/dtrtri.f b/src/lib/lapack/dtrtri.f deleted file mode 100644 index 375813c6..00000000 --- a/src/lib/lapack/dtrtri.f +++ /dev/null @@ -1,176 +0,0 @@ - SUBROUTINE DTRTRI( UPLO, DIAG, N, A, LDA, INFO ) -* -* -- LAPACK routine (version 3.1) -- -* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. -* November 2006 -* -* .. Scalar Arguments .. - CHARACTER DIAG, UPLO - INTEGER INFO, LDA, N -* .. -* .. Array Arguments .. - DOUBLE PRECISION A( LDA, * ) -* .. -* -* Purpose -* ======= -* -* DTRTRI computes the inverse of a real upper or lower triangular -* matrix A. -* -* This is the Level 3 BLAS version of the algorithm. -* -* Arguments -* ========= -* -* UPLO (input) CHARACTER*1 -* = 'U': A is upper triangular; -* = 'L': A is lower triangular. -* -* DIAG (input) CHARACTER*1 -* = '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 (LDA,N) -* On entry, the triangular matrix A. If UPLO = 'U', the -* leading N-by-N upper triangular part of the array A contains -* the upper triangular matrix, and the strictly lower -* triangular part of A is not referenced. If UPLO = 'L', the -* leading N-by-N lower triangular part of the array A contains -* the lower triangular matrix, and the strictly upper -* triangular part of A is not referenced. If DIAG = 'U', the -* diagonal elements of A are also not referenced and are -* assumed to be 1. -* On exit, the (triangular) inverse of the original matrix, in -* the same storage format. -* -* LDA (input) INTEGER -* The leading dimension of the array A. LDA >= max(1,N). -* -* 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. -* -* ===================================================================== -* -* .. Parameters .. - DOUBLE PRECISION ONE, ZERO - PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 ) -* .. -* .. Local Scalars .. - LOGICAL NOUNIT, UPPER - INTEGER J, JB, NB, NN -* .. -* .. External Functions .. - LOGICAL LSAME - INTEGER ILAENV - EXTERNAL LSAME, ILAENV -* .. -* .. External Subroutines .. - EXTERNAL DTRMM, DTRSM, DTRTI2, XERBLA -* .. -* .. Intrinsic Functions .. - INTRINSIC MAX, MIN -* .. -* .. Executable Statements .. -* -* Test the input parameters. -* - INFO = 0 - UPPER = LSAME( UPLO, 'U' ) - NOUNIT = LSAME( DIAG, 'N' ) - IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN - INFO = -1 - ELSE IF( .NOT.NOUNIT .AND. .NOT.LSAME( DIAG, 'U' ) ) THEN - INFO = -2 - ELSE IF( N.LT.0 ) THEN - INFO = -3 - ELSE IF( LDA.LT.MAX( 1, N ) ) THEN - INFO = -5 - END IF - IF( INFO.NE.0 ) THEN - CALL XERBLA( 'DTRTRI', -INFO ) - RETURN - END IF -* -* Quick return if possible -* - IF( N.EQ.0 ) - $ RETURN -* -* Check for singularity if non-unit. -* - IF( NOUNIT ) THEN - DO 10 INFO = 1, N - IF( A( INFO, INFO ).EQ.ZERO ) - $ RETURN - 10 CONTINUE - INFO = 0 - END IF -* -* Determine the block size for this environment. -* - NB = ILAENV( 1, 'DTRTRI', UPLO // DIAG, N, -1, -1, -1 ) - IF( NB.LE.1 .OR. NB.GE.N ) THEN -* -* Use unblocked code -* - CALL DTRTI2( UPLO, DIAG, N, A, LDA, INFO ) - ELSE -* -* Use blocked code -* - IF( UPPER ) THEN -* -* Compute inverse of upper triangular matrix -* - DO 20 J = 1, N, NB - JB = MIN( NB, N-J+1 ) -* -* Compute rows 1:j-1 of current block column -* - CALL DTRMM( 'Left', 'Upper', 'No transpose', DIAG, J-1, - $ JB, ONE, A, LDA, A( 1, J ), LDA ) - CALL DTRSM( 'Right', 'Upper', 'No transpose', DIAG, J-1, - $ JB, -ONE, A( J, J ), LDA, A( 1, J ), LDA ) -* -* Compute inverse of current diagonal block -* - CALL DTRTI2( 'Upper', DIAG, JB, A( J, J ), LDA, INFO ) - 20 CONTINUE - ELSE -* -* Compute inverse of lower triangular matrix -* - NN = ( ( N-1 ) / NB )*NB + 1 - DO 30 J = NN, 1, -NB - JB = MIN( NB, N-J+1 ) - IF( J+JB.LE.N ) THEN -* -* Compute rows j+jb:n of current block column -* - CALL DTRMM( 'Left', 'Lower', 'No transpose', DIAG, - $ N-J-JB+1, JB, ONE, A( J+JB, J+JB ), LDA, - $ A( J+JB, J ), LDA ) - CALL DTRSM( 'Right', 'Lower', 'No transpose', DIAG, - $ N-J-JB+1, JB, -ONE, A( J, J ), LDA, - $ A( J+JB, J ), LDA ) - END IF -* -* Compute inverse of current diagonal block -* - CALL DTRTI2( 'Lower', DIAG, JB, A( J, J ), LDA, INFO ) - 30 CONTINUE - END IF - END IF -* - RETURN -* -* End of DTRTRI -* - END |