Section 3: library functions
slaein.f – Synopsis Functions/Subroutines subroutine slaein (RIGHTV, NOINIT, N, H, LDH, WR, WI, VR, VI, B, LDB, WORK, EPS3, SMLNUM, BIGNUM, INFO) SLAEIN computes a specified right or left eigenvector of an upper Hessenberg matrix by inverse iteration. Function/Subroutine Documentation subroutine slaein (logicalRIGHTV, logicalNOINIT, integerN, real, dimension( ldh, * )H, integerLDH, realWR, realWI, real, dimension(…
slaeda.f – Synopsis Functions/Subroutines subroutine slaeda (N, TLVLS, CURLVL, CURPBM, PRMPTR, PERM, GIVPTR, GIVCOL, GIVNUM, Q, QPTR, Z, ZTEMP, INFO) SLAEDA used by sstedc. Computes the Z vector determining the rank-one modification of the diagonal matrix. Used when the original matrix is dense. Function/Subroutine Documentation subroutine slaeda (integerN, integerTLVLS, integerCURLVL, integerCURPBM, integer, dimension( * )PRMPTR,…
slaed9.f – Synopsis Functions/Subroutines subroutine slaed9 (K, KSTART, KSTOP, N, D, Q, LDQ, RHO, DLAMDA, W, S, LDS, INFO) SLAED9 used by sstedc. Finds the roots of the secular equation and updates the eigenvectors. Used when the original matrix is dense. Function/Subroutine Documentation subroutine slaed9 (integerK, integerKSTART, integerKSTOP, integerN, real, dimension( * )D, real, dimension(…
slaed8.f – Synopsis Functions/Subroutines subroutine slaed8 (ICOMPQ, K, N, QSIZ, D, Q, LDQ, INDXQ, RHO, CUTPNT, Z, DLAMDA, Q2, LDQ2, W, PERM, GIVPTR, GIVCOL, GIVNUM, INDXP, INDX, INFO) SLAED8 used by sstedc. Merges eigenvalues and deflates secular equation. Used when the original matrix is dense. Function/Subroutine Documentation subroutine slaed8 (integerICOMPQ, integerK, integerN, integerQSIZ, real, dimension(…
slaed7.f – Synopsis Functions/Subroutines subroutine slaed7 (ICOMPQ, N, QSIZ, TLVLS, CURLVL, CURPBM, D, Q, LDQ, INDXQ, RHO, CUTPNT, QSTORE, QPTR, PRMPTR, PERM, GIVPTR, GIVCOL, GIVNUM, WORK, IWORK, INFO) SLAED7 used by sstedc. Computes the updated eigensystem of a diagonal matrix after modification by a rank-one symmetric matrix. Used when the original matrix is dense. Function/Subroutine…
slaed6.f – Synopsis Functions/Subroutines subroutine slaed6 (KNITER, ORGATI, RHO, D, Z, FINIT, TAU, INFO) SLAED6 used by sstedc. Computes one Newton step in solution of the secular equation. Function/Subroutine Documentation subroutine slaed6 (integerKNITER, logicalORGATI, realRHO, real, dimension( 3 )D, real, dimension( 3 )Z, realFINIT, realTAU, integerINFO) SLAED6 used by sstedc. Computes one Newton step in…
slaed5.f – Synopsis Functions/Subroutines subroutine slaed5 (I, D, Z, DELTA, RHO, DLAM) SLAED5 used by sstedc. Solves the 2-by-2 secular equation. Function/Subroutine Documentation subroutine slaed5 (integerI, real, dimension( 2 )D, real, dimension( 2 )Z, real, dimension( 2 )DELTA, realRHO, realDLAM) SLAED5 used by sstedc. Solves the 2-by-2 secular equation. Purpose: This subroutine computes the I-th…
slaed4.f – Synopsis Functions/Subroutines subroutine slaed4 (N, I, D, Z, DELTA, RHO, DLAM, INFO) SLAED4 used by sstedc. Finds a single root of the secular equation. Function/Subroutine Documentation subroutine slaed4 (integerN, integerI, real, dimension( * )D, real, dimension( * )Z, real, dimension( * )DELTA, realRHO, realDLAM, integerINFO) SLAED4 used by sstedc. Finds a single root…
slaed3.f – SynopsisFunctions/Subroutinessubroutine slaed3 (K, N, N1, D, Q, LDQ, RHO, DLAMDA, Q2, INDX, CTOT, W, S, INFO) SLAED3 used by sstedc. Finds the roots of the secular equation and updates the eigenvectors. Used when the original matrix is tridiagonal. Function/Subroutine Documentationsubroutine slaed3 (integerK, integerN, integerN1, real, dimension( * )D, real, dimension( ldq, * )Q,…
slaed2.f – Synopsis Functions/Subroutines subroutine slaed2 (K, N, N1, D, Q, LDQ, INDXQ, RHO, Z, DLAMDA, W, Q2, INDX, INDXC, INDXP, COLTYP, INFO) SLAED2 used by sstedc. Merges eigenvalues and deflates secular equation. Used when the original matrix is tridiagonal. Function/Subroutine Documentation subroutine slaed2 (integerK, integerN, integerN1, real, dimension( * )D, real, dimension( ldq, *…
slaed1.f – Synopsis Functions/Subroutines subroutine slaed1 (N, D, Q, LDQ, INDXQ, RHO, CUTPNT, WORK, IWORK, INFO) SLAED1 used by sstedc. Computes the updated eigensystem of a diagonal matrix after modification by a rank-one symmetric matrix. Used when the original matrix is tridiagonal. Function/Subroutine Documentation subroutine slaed1 (integerN, real, dimension( * )D, real, dimension( ldq, *…
slaed0.f – Synopsis Functions/Subroutines subroutine slaed0 (ICOMPQ, QSIZ, N, D, E, Q, LDQ, QSTORE, LDQS, WORK, IWORK, INFO) SLAED0 used by sstedc. Computes all eigenvalues and corresponding eigenvectors of an unreduced symmetric tridiagonal matrix using the divide and conquer method. Function/Subroutine Documentation subroutine slaed0 (integerICOMPQ, integerQSIZ, integerN, real, dimension( * )D, real, dimension( * )E,…
slaebz.f – Synopsis Functions/Subroutines subroutine slaebz (IJOB, NITMAX, N, MMAX, MINP, NBMIN, ABSTOL, RELTOL, PIVMIN, D, E, E2, NVAL, AB, C, MOUT, NAB, WORK, IWORK, INFO) SLAEBZ computes the number of eigenvalues of a real symmetric tridiagonal matrix which are less than or equal to a given value, and performs other tasks required by the…
slae2.f – Synopsis Functions/Subroutines subroutine slae2 (A, B, C, RT1, RT2) SLAE2 computes the eigenvalues of a 2-by-2 symmetric matrix. Function/Subroutine Documentation subroutine slae2 (realA, realB, realC, realRT1, realRT2) SLAE2 computes the eigenvalues of a 2-by-2 symmetric matrix. Purpose: SLAE2 computes the eigenvalues of a 2-by-2 symmetric matrix [ A B ] [ B C…
sladiv.f – Synopsis Functions/Subroutines subroutine sladiv (A, B, C, D, P, Q) SLADIV performs complex division in real arithmetic, avoiding unnecessary overflow. subroutine sladiv1 (A, B, C, D, P, Q) REAL function sladiv2 (A, B, C, D, R, T) Function/Subroutine Documentation subroutine sladiv (realA, realB, realC, realD, realP, realQ) SLADIV performs complex division in real…
slacpy.f – Synopsis Functions/Subroutines subroutine slacpy (UPLO, M, N, A, LDA, B, LDB) SLACPY copies all or part of one two-dimensional array to another. Function/Subroutine Documentation subroutine slacpy (characterUPLO, integerM, integerN, real, dimension( lda, * )A, integerLDA, real, dimension( ldb, * )B, integerLDB) SLACPY copies all or part of one two-dimensional array to another. Purpose:…
slacon.f – Synopsis Functions/Subroutines subroutine slacon (N, V, X, ISGN, EST, KASE) SLACON estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products. Function/Subroutine Documentation subroutine slacon (integerN, real, dimension( * )V, real, dimension( * )X, integer, dimension( * )ISGN, realEST, integerKASE) SLACON estimates the 1-norm of a square matrix, using…
slacn2.f – SynopsisFunctions/Subroutinessubroutine slacn2 (N, V, X, ISGN, EST, KASE, ISAVE) SLACN2 estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products. Function/Subroutine Documentationsubroutine slacn2 (integerN, real, dimension( * )V, real, dimension( * )X, integer, dimension( * )ISGN, realEST, integerKASE, integer, dimension( 3 )ISAVE)SLACN2 estimates the 1-norm of a square matrix,…
slabrd.f – Synopsis Functions/Subroutines subroutine slabrd (M, N, NB, A, LDA, D, E, TAUQ, TAUP, X, LDX, Y, LDY) SLABRD reduces the first nb rows and columns of a general matrix to a bidiagonal form. Function/Subroutine Documentation subroutine slabrd (integerM, integerN, integerNB, real, dimension( lda, * )A, integerLDA, real, dimension( * )D, real, dimension( *…
slabad.f – SynopsisFunctions/Subroutinessubroutine slabad (SMALL, LARGE) SLABAD Function/Subroutine Documentationsubroutine slabad (realSMALL, realLARGE)SLABAD Purpose: SLABAD takes as input the values computed by SLAMCH for underflow and overflow, and returns the square root of each of these values if the log of LARGE is sufficiently large. This subroutine is intended to identify machines with a large exponent…