*> \brief \b SLAMRG creates a permutation list to merge the entries of two independently sorted sets into a single set sorted in ascending order. * * =========== DOCUMENTATION =========== * * Online html documentation available at * http://www.netlib.org/lapack/explore-html/ * *> \htmlonly *> Download SLAMRG + dependencies *> *> [TGZ] *> *> [ZIP] *> *> [TXT] *> \endhtmlonly * * Definition: * =========== * * SUBROUTINE SLAMRG( N1, N2, A, STRD1, STRD2, INDEX ) * * .. Scalar Arguments .. * INTEGER N1, N2, STRD1, STRD2 * .. * .. Array Arguments .. * INTEGER INDEX( * ) * REAL A( * ) * .. * * *> \par Purpose: * ============= *> *> \verbatim *> *> SLAMRG will create a permutation list which will merge the elements *> of A (which is composed of two independently sorted sets) into a *> single set which is sorted in ascending order. *> \endverbatim * * Arguments: * ========== * *> \param[in] N1 *> \verbatim *> N1 is INTEGER *> \endverbatim *> *> \param[in] N2 *> \verbatim *> N2 is INTEGER *> These arguments contain the respective lengths of the two *> sorted lists to be merged. *> \endverbatim *> *> \param[in] A *> \verbatim *> A is REAL array, dimension (N1+N2) *> The first N1 elements of A contain a list of numbers which *> are sorted in either ascending or descending order. Likewise *> for the final N2 elements. *> \endverbatim *> *> \param[in] STRD1 *> \verbatim *> STRD1 is INTEGER *> \endverbatim *> *> \param[in] STRD2 *> \verbatim *> STRD2 is INTEGER *> These are the strides to be taken through the array A. *> Allowable strides are 1 and -1. They indicate whether a *> subset of A is sorted in ascending (STRDx = 1) or descending *> (STRDx = -1) order. *> \endverbatim *> *> \param[out] INDEX *> \verbatim *> INDEX is INTEGER array, dimension (N1+N2) *> On exit this array will contain a permutation such that *> if B( I ) = A( INDEX( I ) ) for I=1,N1+N2, then B will be *> sorted in ascending order. *> \endverbatim * * Authors: * ======== * *> \author Univ. of Tennessee *> \author Univ. of California Berkeley *> \author Univ. of Colorado Denver *> \author NAG Ltd. * *> \ingroup auxOTHERcomputational * * ===================================================================== SUBROUTINE SLAMRG( N1, N2, A, STRD1, STRD2, INDEX ) * * -- LAPACK computational routine -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- * * .. Scalar Arguments .. INTEGER N1, N2, STRD1, STRD2 * .. * .. Array Arguments .. INTEGER INDEX( * ) REAL A( * ) * .. * * ===================================================================== * * .. Local Scalars .. INTEGER I, IND1, IND2, N1SV, N2SV * .. * .. Executable Statements .. * N1SV = N1 N2SV = N2 IF( STRD1.GT.0 ) THEN IND1 = 1 ELSE IND1 = N1 END IF IF( STRD2.GT.0 ) THEN IND2 = 1 + N1 ELSE IND2 = N1 + N2 END IF I = 1 * while ( (N1SV > 0) & (N2SV > 0) ) 10 CONTINUE IF( N1SV.GT.0 .AND. N2SV.GT.0 ) THEN IF( A( IND1 ).LE.A( IND2 ) ) THEN INDEX( I ) = IND1 I = I + 1 IND1 = IND1 + STRD1 N1SV = N1SV - 1 ELSE INDEX( I ) = IND2 I = I + 1 IND2 = IND2 + STRD2 N2SV = N2SV - 1 END IF GO TO 10 END IF * end while IF( N1SV.EQ.0 ) THEN DO 20 N1SV = 1, N2SV INDEX( I ) = IND2 I = I + 1 IND2 = IND2 + STRD2 20 CONTINUE ELSE * N2SV .EQ. 0 DO 30 N2SV = 1, N1SV INDEX( I ) = IND1 I = I + 1 IND1 = IND1 + STRD1 30 CONTINUE END IF * RETURN * * End of SLAMRG * END