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Diffstat (limited to 'src/lib/lapack/zgetc2.f')
| -rw-r--r-- | src/lib/lapack/zgetc2.f | 145 |
1 files changed, 0 insertions, 145 deletions
diff --git a/src/lib/lapack/zgetc2.f b/src/lib/lapack/zgetc2.f deleted file mode 100644 index 35ac376c..00000000 --- a/src/lib/lapack/zgetc2.f +++ /dev/null @@ -1,145 +0,0 @@ - SUBROUTINE ZGETC2( N, A, LDA, IPIV, JPIV, INFO ) -* -* -- LAPACK auxiliary routine (version 3.1) -- -* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. -* November 2006 -* -* .. Scalar Arguments .. - INTEGER INFO, LDA, N -* .. -* .. Array Arguments .. - INTEGER IPIV( * ), JPIV( * ) - COMPLEX*16 A( LDA, * ) -* .. -* -* Purpose -* ======= -* -* ZGETC2 computes an LU factorization, using complete pivoting, of the -* n-by-n matrix A. The factorization has the form A = P * L * U * Q, -* where P and Q are permutation matrices, L is lower triangular with -* unit diagonal elements and U is upper triangular. -* -* This is a level 1 BLAS version of the algorithm. -* -* Arguments -* ========= -* -* N (input) INTEGER -* The order of the matrix A. N >= 0. -* -* A (input/output) COMPLEX*16 array, dimension (LDA, N) -* On entry, the n-by-n matrix to be factored. -* On exit, the factors L and U from the factorization -* A = P*L*U*Q; the unit diagonal elements of L are not stored. -* If U(k, k) appears to be less than SMIN, U(k, k) is given the -* value of SMIN, giving a nonsingular perturbed system. -* -* LDA (input) INTEGER -* The leading dimension of the array A. LDA >= max(1, N). -* -* IPIV (output) INTEGER array, dimension (N). -* The pivot indices; for 1 <= i <= N, row i of the -* matrix has been interchanged with row IPIV(i). -* -* JPIV (output) INTEGER array, dimension (N). -* The pivot indices; for 1 <= j <= N, column j of the -* matrix has been interchanged with column JPIV(j). -* -* INFO (output) INTEGER -* = 0: successful exit -* > 0: if INFO = k, U(k, k) is likely to produce overflow if -* one tries to solve for x in Ax = b. So U is perturbed -* to avoid the overflow. -* -* Further Details -* =============== -* -* Based on contributions by -* Bo Kagstrom and Peter Poromaa, Department of Computing Science, -* Umea University, S-901 87 Umea, Sweden. -* -* ===================================================================== -* -* .. Parameters .. - DOUBLE PRECISION ZERO, ONE - PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 ) -* .. -* .. Local Scalars .. - INTEGER I, IP, IPV, J, JP, JPV - DOUBLE PRECISION BIGNUM, EPS, SMIN, SMLNUM, XMAX -* .. -* .. External Subroutines .. - EXTERNAL ZGERU, ZSWAP -* .. -* .. External Functions .. - DOUBLE PRECISION DLAMCH - EXTERNAL DLAMCH -* .. -* .. Intrinsic Functions .. - INTRINSIC ABS, DCMPLX, MAX -* .. -* .. Executable Statements .. -* -* Set constants to control overflow -* - INFO = 0 - EPS = DLAMCH( 'P' ) - SMLNUM = DLAMCH( 'S' ) / EPS - BIGNUM = ONE / SMLNUM - CALL DLABAD( SMLNUM, BIGNUM ) -* -* Factorize A using complete pivoting. -* Set pivots less than SMIN to SMIN -* - DO 40 I = 1, N - 1 -* -* Find max element in matrix A -* - XMAX = ZERO - DO 20 IP = I, N - DO 10 JP = I, N - IF( ABS( A( IP, JP ) ).GE.XMAX ) THEN - XMAX = ABS( A( IP, JP ) ) - IPV = IP - JPV = JP - END IF - 10 CONTINUE - 20 CONTINUE - IF( I.EQ.1 ) - $ SMIN = MAX( EPS*XMAX, SMLNUM ) -* -* Swap rows -* - IF( IPV.NE.I ) - $ CALL ZSWAP( N, A( IPV, 1 ), LDA, A( I, 1 ), LDA ) - IPIV( I ) = IPV -* -* Swap columns -* - IF( JPV.NE.I ) - $ CALL ZSWAP( N, A( 1, JPV ), 1, A( 1, I ), 1 ) - JPIV( I ) = JPV -* -* Check for singularity -* - IF( ABS( A( I, I ) ).LT.SMIN ) THEN - INFO = I - A( I, I ) = DCMPLX( SMIN, ZERO ) - END IF - DO 30 J = I + 1, N - A( J, I ) = A( J, I ) / A( I, I ) - 30 CONTINUE - CALL ZGERU( N-I, N-I, -DCMPLX( ONE ), A( I+1, I ), 1, - $ A( I, I+1 ), LDA, A( I+1, I+1 ), LDA ) - 40 CONTINUE -* - IF( ABS( A( N, N ) ).LT.SMIN ) THEN - INFO = N - A( N, N ) = DCMPLX( SMIN, ZERO ) - END IF - RETURN -* -* End of ZGETC2 -* - END |