dlagv2.f – Synopsis Functions/Subroutines subroutine dlagv2 (A, LDA, B, LDB, ALPHAR, ALPHAI, BETA, CSL, SNL, CSR, SNR) DLAGV2 computes the Generalized Schur factorization of a real 2-by-2 matrix pencil (A,B) where B is upper triangular. Function/Subroutine Documentation subroutine dlagv2 (double precision, dimension( lda, * )A, integerLDA, double precision, dimension( ldb, * )B, integerLDB, double precision,…
dlagts.f – Synopsis Functions/Subroutines subroutine dlagts (JOB, N, A, B, C, D, IN, Y, TOL, INFO) DLAGTS solves the system of equations (T-λI)x = y or (T-λI)Tx = y,where T is a general tridiagonal matrix and λ a scalar, using the LU factorization computed by slagtf. Function/Subroutine Documentation subroutine dlagts (integerJOB, integerN, double precision, dimension(…
dlagtm.f – Synopsis Functions/Subroutines subroutine dlagtm (TRANS, N, NRHS, ALPHA, DL, D, DU, X, LDX, BETA, B, LDB) DLAGTM performs a matrix-matrix product of the form C = αAB+βC, where A is a tridiagonal matrix, B and C are rectangular matrices, and α and β are scalars, which may be 0, 1, or -1. Function/Subroutine…
dlagtf.f – Synopsis Functions/Subroutines subroutine dlagtf (N, A, LAMBDA, B, C, TOL, D, IN, INFO) DLAGTF computes an LU factorization of a matrix T-λI, where T is a general tridiagonal matrix, and λ a scalar, using partial pivoting with row interchanges. Function/Subroutine Documentation subroutine dlagtf (integerN, double precision, dimension( * )A, double precisionLAMBDA, double precision,…
dlags2.f – Synopsis Functions/Subroutines subroutine dlags2 (UPPER, A1, A2, A3, B1, B2, B3, CSU, SNU, CSV, SNV, CSQ, SNQ) DLAGS2 computes 2-by-2 orthogonal matrices U, V, and Q, and applies them to matrices A and B such that the rows of the transformed A and B are parallel. Function/Subroutine Documentation subroutine dlags2 (logicalUPPER, double precisionA1,…
dlag2s.f – Synopsis Functions/Subroutines subroutine dlag2s (M, N, A, LDA, SA, LDSA, INFO) DLAG2S converts a double precision matrix to a single precision matrix. Function/Subroutine Documentation subroutine dlag2s (integerM, integerN, double precision, dimension( lda, * )A, integerLDA, real, dimension( ldsa, * )SA, integerLDSA, integerINFO) DLAG2S converts a double precision matrix to a single precision matrix….
dlag2.f – Synopsis Functions/Subroutines subroutine dlag2 (A, LDA, B, LDB, SAFMIN, SCALE1, SCALE2, WR1, WR2, WI) DLAG2 computes the eigenvalues of a 2-by-2 generalized eigenvalue problem, with scaling as necessary to avoid over-/underflow. Function/Subroutine Documentation subroutine dlag2 (double precision, dimension( lda, * )A, integerLDA, double precision, dimension( ldb, * )B, integerLDB, double precisionSAFMIN, double precisionSCALE1,…
dlaexc.f – Synopsis Functions/Subroutines subroutine dlaexc (WANTQ, N, T, LDT, Q, LDQ, J1, N1, N2, WORK, INFO) DLAEXC swaps adjacent diagonal blocks of a real upper quasi-triangular matrix in Schur canonical form, by an orthogonal similarity transformation. Function/Subroutine Documentation subroutine dlaexc (logicalWANTQ, integerN, double precision, dimension( ldt, * )T, integerLDT, double precision, dimension( ldq, *…
dlaev2.f – Synopsis Functions/Subroutines subroutine dlaev2 (A, B, C, RT1, RT2, CS1, SN1) DLAEV2 computes the eigenvalues and eigenvectors of a 2-by-2 symmetric/Hermitian matrix. Function/Subroutine Documentation subroutine dlaev2 (double precisionA, double precisionB, double precisionC, double precisionRT1, double precisionRT2, double precisionCS1, double precisionSN1) DLAEV2 computes the eigenvalues and eigenvectors of a 2-by-2 symmetric/Hermitian matrix. Purpose: DLAEV2…
dlaein.f – Synopsis Functions/Subroutines subroutine dlaein (RIGHTV, NOINIT, N, H, LDH, WR, WI, VR, VI, B, LDB, WORK, EPS3, SMLNUM, BIGNUM, INFO) DLAEIN computes a specified right or left eigenvector of an upper Hessenberg matrix by inverse iteration. Function/Subroutine Documentation subroutine dlaein (logicalRIGHTV, logicalNOINIT, integerN, double precision, dimension( ldh, * )H, integerLDH, double precisionWR, double…
dlaeda.f – Synopsis Functions/Subroutines subroutine dlaeda (N, TLVLS, CURLVL, CURPBM, PRMPTR, PERM, GIVPTR, GIVCOL, GIVNUM, Q, QPTR, Z, ZTEMP, INFO) DLAEDA 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 dlaeda (integerN, integerTLVLS, integerCURLVL, integerCURPBM, integer, dimension( * )PRMPTR,…
dlaed9.f – Synopsis Functions/Subroutines subroutine dlaed9 (K, KSTART, KSTOP, N, D, Q, LDQ, RHO, DLAMDA, W, S, LDS, INFO) DLAED9 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 dlaed9 (integerK, integerKSTART, integerKSTOP, integerN, double precision, dimension( * )D, double…
dlaed8.f – Synopsis Functions/Subroutines subroutine dlaed8 (ICOMPQ, K, N, QSIZ, D, Q, LDQ, INDXQ, RHO, CUTPNT, Z, DLAMDA, Q2, LDQ2, W, PERM, GIVPTR, GIVCOL, GIVNUM, INDXP, INDX, INFO) DLAED8 used by sstedc. Merges eigenvalues and deflates secular equation. Used when the original matrix is dense. Function/Subroutine Documentation subroutine dlaed8 (integerICOMPQ, integerK, integerN, integerQSIZ, double precision,…
dlaed7.f – Synopsis Functions/Subroutines subroutine dlaed7 (ICOMPQ, N, QSIZ, TLVLS, CURLVL, CURPBM, D, Q, LDQ, INDXQ, RHO, CUTPNT, QSTORE, QPTR, PRMPTR, PERM, GIVPTR, GIVCOL, GIVNUM, WORK, IWORK, INFO) DLAED7 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…
dlaed6.f – Synopsis Functions/Subroutines subroutine dlaed6 (KNITER, ORGATI, RHO, D, Z, FINIT, TAU, INFO) DLAED6 used by sstedc. Computes one Newton step in solution of the secular equation. Function/Subroutine Documentation subroutine dlaed6 (integerKNITER, logicalORGATI, double precisionRHO, double precision, dimension( 3 )D, double precision, dimension( 3 )Z, double precisionFINIT, double precisionTAU, integerINFO) DLAED6 used by sstedc….
dlaed5.f – Synopsis Functions/Subroutines subroutine dlaed5 (I, D, Z, DELTA, RHO, DLAM) DLAED5 used by sstedc. Solves the 2-by-2 secular equation. Function/Subroutine Documentation subroutine dlaed5 (integerI, double precision, dimension( 2 )D, double precision, dimension( 2 )Z, double precision, dimension( 2 )DELTA, double precisionRHO, double precisionDLAM) DLAED5 used by sstedc. Solves the 2-by-2 secular equation. Purpose:…
dlaed4.f – Synopsis Functions/Subroutines subroutine dlaed4 (N, I, D, Z, DELTA, RHO, DLAM, INFO) DLAED4 used by sstedc. Finds a single root of the secular equation. Function/Subroutine Documentation subroutine dlaed4 (integerN, integerI, double precision, dimension( * )D, double precision, dimension( * )Z, double precision, dimension( * )DELTA, double precisionRHO, double precisionDLAM, integerINFO) DLAED4 used by…
dlaed3.f – Synopsis Functions/Subroutines subroutine dlaed3 (K, N, N1, D, Q, LDQ, RHO, DLAMDA, Q2, INDX, CTOT, W, S, INFO) DLAED3 used by sstedc. Finds the roots of the secular equation and updates the eigenvectors. Used when the original matrix is tridiagonal. Function/Subroutine Documentation subroutine dlaed3 (integerK, integerN, integerN1, double precision, dimension( * )D, double…
dlaed2.f – Synopsis Functions/Subroutines subroutine dlaed2 (K, N, N1, D, Q, LDQ, INDXQ, RHO, Z, DLAMDA, W, Q2, INDX, INDXC, INDXP, COLTYP, INFO) DLAED2 used by sstedc. Merges eigenvalues and deflates secular equation. Used when the original matrix is tridiagonal. Function/Subroutine Documentation subroutine dlaed2 (integerK, integerN, integerN1, double precision, dimension( * )D, double precision, dimension(…
dlaed1.f – Synopsis Functions/Subroutines subroutine dlaed1 (N, D, Q, LDQ, INDXQ, RHO, CUTPNT, WORK, IWORK, INFO) DLAED1 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 dlaed1 (integerN, double precision, dimension( * )D, double precision, dimension(…