diff options
Diffstat (limited to 'src/lib/lapack/dsycon.f')
| -rw-r--r-- | src/lib/lapack/dsycon.f | 165 |
1 files changed, 0 insertions, 165 deletions
diff --git a/src/lib/lapack/dsycon.f b/src/lib/lapack/dsycon.f deleted file mode 100644 index 711b48ca..00000000 --- a/src/lib/lapack/dsycon.f +++ /dev/null @@ -1,165 +0,0 @@ - SUBROUTINE DSYCON( UPLO, N, A, LDA, IPIV, ANORM, RCOND, WORK, - $ IWORK, INFO ) -* -* -- LAPACK routine (version 3.1) -- -* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. -* November 2006 -* -* Modified to call DLACN2 in place of DLACON, 5 Feb 03, SJH. -* -* .. Scalar Arguments .. - CHARACTER UPLO - INTEGER INFO, LDA, N - DOUBLE PRECISION ANORM, RCOND -* .. -* .. Array Arguments .. - INTEGER IPIV( * ), IWORK( * ) - DOUBLE PRECISION A( LDA, * ), WORK( * ) -* .. -* -* Purpose -* ======= -* -* DSYCON estimates the reciprocal of the condition number (in the -* 1-norm) of a real symmetric matrix A using the factorization -* A = U*D*U**T or A = L*D*L**T computed by DSYTRF. -* -* An estimate is obtained for norm(inv(A)), and the reciprocal of the -* condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))). -* -* Arguments -* ========= -* -* UPLO (input) CHARACTER*1 -* Specifies whether the details of the factorization are stored -* as an upper or lower triangular matrix. -* = 'U': Upper triangular, form is A = U*D*U**T; -* = 'L': Lower triangular, form is A = L*D*L**T. -* -* N (input) INTEGER -* The order of the matrix A. N >= 0. -* -* A (input) DOUBLE PRECISION array, dimension (LDA,N) -* The block diagonal matrix D and the multipliers used to -* obtain the factor U or L as computed by DSYTRF. -* -* LDA (input) INTEGER -* The leading dimension of the array A. LDA >= max(1,N). -* -* IPIV (input) INTEGER array, dimension (N) -* Details of the interchanges and the block structure of D -* as determined by DSYTRF. -* -* ANORM (input) DOUBLE PRECISION -* The 1-norm of the original matrix A. -* -* RCOND (output) DOUBLE PRECISION -* The reciprocal of the condition number of the matrix A, -* computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an -* estimate of the 1-norm of inv(A) computed in this routine. -* -* WORK (workspace) DOUBLE PRECISION array, dimension (2*N) -* -* IWORK (workspace) INTEGER array, dimension (N) -* -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -i, the i-th argument had an illegal value -* -* ===================================================================== -* -* .. Parameters .. - DOUBLE PRECISION ONE, ZERO - PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 ) -* .. -* .. Local Scalars .. - LOGICAL UPPER - INTEGER I, KASE - DOUBLE PRECISION AINVNM -* .. -* .. Local Arrays .. - INTEGER ISAVE( 3 ) -* .. -* .. External Functions .. - LOGICAL LSAME - EXTERNAL LSAME -* .. -* .. External Subroutines .. - EXTERNAL DLACN2, DSYTRS, XERBLA -* .. -* .. Intrinsic Functions .. - INTRINSIC MAX -* .. -* .. Executable Statements .. -* -* Test the input parameters. -* - INFO = 0 - UPPER = LSAME( UPLO, 'U' ) - IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN - INFO = -1 - ELSE IF( N.LT.0 ) THEN - INFO = -2 - ELSE IF( LDA.LT.MAX( 1, N ) ) THEN - INFO = -4 - ELSE IF( ANORM.LT.ZERO ) THEN - INFO = -6 - END IF - IF( INFO.NE.0 ) THEN - CALL XERBLA( 'DSYCON', -INFO ) - RETURN - END IF -* -* Quick return if possible -* - RCOND = ZERO - IF( N.EQ.0 ) THEN - RCOND = ONE - RETURN - ELSE IF( ANORM.LE.ZERO ) THEN - RETURN - END IF -* -* Check that the diagonal matrix D is nonsingular. -* - IF( UPPER ) THEN -* -* Upper triangular storage: examine D from bottom to top -* - DO 10 I = N, 1, -1 - IF( IPIV( I ).GT.0 .AND. A( I, I ).EQ.ZERO ) - $ RETURN - 10 CONTINUE - ELSE -* -* Lower triangular storage: examine D from top to bottom. -* - DO 20 I = 1, N - IF( IPIV( I ).GT.0 .AND. A( I, I ).EQ.ZERO ) - $ RETURN - 20 CONTINUE - END IF -* -* Estimate the 1-norm of the inverse. -* - KASE = 0 - 30 CONTINUE - CALL DLACN2( N, WORK( N+1 ), WORK, IWORK, AINVNM, KASE, ISAVE ) - IF( KASE.NE.0 ) THEN -* -* Multiply by inv(L*D*L') or inv(U*D*U'). -* - CALL DSYTRS( UPLO, N, 1, A, LDA, IPIV, WORK, N, INFO ) - GO TO 30 - END IF -* -* Compute the estimate of the reciprocal condition number. -* - IF( AINVNM.NE.ZERO ) - $ RCOND = ( ONE / AINVNM ) / ANORM -* - RETURN -* -* End of DSYCON -* - END |