Section 3: library functions
NAME dlatrd.f – SYNOPSIS Functions/Subroutines subroutine dlatrd (UPLO, N, NB, A, LDA, E, TAU, W, LDW) DLATRD reduces the first nb rows and columns of a symmetric/Hermitian matrix A to real tridiagonal form by an orthogonal similarity transformation. Function/Subroutine Documentation subroutine dlatrd (characterUPLO, integerN, integerNB, double precision, dimension( lda, * )A, integerLDA, double precision, dimension(…
NAME dlatps.f – SYNOPSIS Functions/Subroutines subroutine dlatps (UPLO, TRANS, DIAG, NORMIN, N, AP, X, SCALE, CNORM, INFO) DLATPS solves a triangular system of equations with the matrix held in packed storage. Function/Subroutine Documentation subroutine dlatps (characterUPLO, characterTRANS, characterDIAG, characterNORMIN, integerN, double precision, dimension( * )AP, double precision, dimension( * )X, double precisionSCALE, double precision, dimension(…
NAME dlatdf.f – SYNOPSIS Functions/Subroutines subroutine dlatdf (IJOB, N, Z, LDZ, RHS, RDSUM, RDSCAL, IPIV, JPIV) DLATDF uses the LU factorization of the n-by-n matrix computed by sgetc2 and computes a contribution to the reciprocal Dif-estimate. Function/Subroutine Documentation subroutine dlatdf (integerIJOB, integerN, double precision, dimension( ldz, * )Z, integerLDZ, double precision, dimension( * )RHS, double…
NAME dlatbs.f – SYNOPSIS Functions/Subroutines subroutine dlatbs (UPLO, TRANS, DIAG, NORMIN, N, KD, AB, LDAB, X, SCALE, CNORM, INFO) DLATBS solves a triangular banded system of equations. Function/Subroutine Documentation subroutine dlatbs (characterUPLO, characterTRANS, characterDIAG, characterNORMIN, integerN, integerKD, double precision, dimension( ldab, * )AB, integerLDAB, double precision, dimension( * )X, double precisionSCALE, double precision, dimension( *…
NAME dlat2s.f – SYNOPSIS Functions/Subroutines subroutine dlat2s (UPLO, N, A, LDA, SA, LDSA, INFO) DLAT2S converts a double-precision triangular matrix to a single-precision triangular matrix. Function/Subroutine Documentation subroutine dlat2s (characterUPLO, integerN, double precision, dimension( lda, * )A, integerLDA, real, dimension( ldsa, * )SA, integerLDSA, integerINFO) DLAT2S converts a double-precision triangular matrix to a single-precision triangular…
NAME dlasyf.f – SYNOPSIS Functions/Subroutines subroutine dlasyf (UPLO, N, NB, KB, A, LDA, IPIV, W, LDW, INFO) DLASYF computes a partial factorization of a real symmetric matrix using the Bunch-Kaufman diagonal pivoting method. Function/Subroutine Documentation subroutine dlasyf (characterUPLO, integerN, integerNB, integerKB, double precision, dimension( lda, * )A, integerLDA, integer, dimension( * )IPIV, double precision, dimension(…
NAME dlasy2.f – SYNOPSIS Functions/Subroutines subroutine dlasy2 (LTRANL, LTRANR, ISGN, N1, N2, TL, LDTL, TR, LDTR, B, LDB, SCALE, X, LDX, XNORM, INFO) DLASY2 solves the Sylvester matrix equation where the matrices are of order 1 or 2. Function/Subroutine Documentation subroutine dlasy2 (logicalLTRANL, logicalLTRANR, integerISGN, integerN1, integerN2, double precision, dimension( ldtl, * )TL, integerLDTL, double…
NAME dlaswp.f – SYNOPSIS Functions/Subroutines subroutine dlaswp (N, A, LDA, K1, K2, IPIV, INCX) DLASWP performs a series of row interchanges on a general rectangular matrix. Function/Subroutine Documentation subroutine dlaswp (integerN, double precision, dimension( lda, * )A, integerLDA, integerK1, integerK2, integer, dimension( * )IPIV, integerINCX) DLASWP performs a series of row interchanges on a general…
NAME dlasv2.f – SYNOPSIS Functions/Subroutines subroutine dlasv2 (F, G, H, SSMIN, SSMAX, SNR, CSR, SNL, CSL) DLASV2 computes the singular value decomposition of a 2-by-2 triangular matrix. Function/Subroutine Documentation subroutine dlasv2 (double precisionF, double precisionG, double precisionH, double precisionSSMIN, double precisionSSMAX, double precisionSNR, double precisionCSR, double precisionSNL, double precisionCSL) DLASV2 computes the singular value decomposition…
NAME dlassq.f – SYNOPSIS Functions/Subroutines subroutine dlassq (N, X, INCX, SCALE, SUMSQ) DLASSQ updates a sum of squares represented in scaled form. Function/Subroutine Documentation subroutine dlassq (integerN, double precision, dimension( * )X, integerINCX, double precisionSCALE, double precisionSUMSQ) DLASSQ updates a sum of squares represented in scaled form. Purpose: DLASSQ returns the values scl and smsq…
NAME dlasrt.f – SYNOPSIS Functions/Subroutines subroutine dlasrt (ID, N, D, INFO) DLASRT sorts numbers in increasing or decreasing order. Function/Subroutine Documentation subroutine dlasrt (characterID, integerN, double precision, dimension( * )D, integerINFO) DLASRT sorts numbers in increasing or decreasing order. Purpose: Sort the numbers in D in increasing order (if ID = ‘I’) or in decreasing…
NAME dlasr.f – SYNOPSIS Functions/Subroutines subroutine dlasr (SIDE, PIVOT, DIRECT, M, N, C, S, A, LDA) DLASR applies a sequence of plane rotations to a general rectangular matrix. Function/Subroutine Documentation subroutine dlasr (characterSIDE, characterPIVOT, characterDIRECT, integerM, integerN, double precision, dimension( * )C, double precision, dimension( * )S, double precision, dimension( lda, * )A, integerLDA) DLASR…
NAME dlasq6.f – SYNOPSIS Functions/Subroutines subroutine dlasq6 (I0, N0, Z, PP, DMIN, DMIN1, DMIN2, DN, DNM1, DNM2) DLASQ6 computes one dqd transform in ping-pong form. Used by sbdsqr and sstegr. Function/Subroutine Documentation subroutine dlasq6 (integerI0, integerN0, double precision, dimension( * )Z, integerPP, double precisionDMIN, double precisionDMIN1, double precisionDMIN2, double precisionDN, double precisionDNM1, double precisionDNM2) DLASQ6…
NAME dlasq5.f – SYNOPSIS Functions/Subroutines subroutine dlasq5 (I0, N0, Z, PP, TAU, SIGMA, DMIN, DMIN1, DMIN2, DN, DNM1, DNM2, IEEE, EPS) DLASQ5 computes one dqds transform in ping-pong form. Used by sbdsqr and sstegr. Function/Subroutine Documentation subroutine dlasq5 (integerI0, integerN0, double precision, dimension( * )Z, integerPP, double precisionTAU, double precisionSIGMA, double precisionDMIN, double precisionDMIN1, double…
NAME dlasq4.f – SYNOPSIS Functions/Subroutines subroutine dlasq4 (I0, N0, Z, PP, N0IN, DMIN, DMIN1, DMIN2, DN, DN1, DN2, TAU, TTYPE, G) DLASQ4 computes an approximation to the smallest eigenvalue using values of d from the previous transform. Used by sbdsqr. Function/Subroutine Documentation subroutine dlasq4 (integerI0, integerN0, double precision, dimension( * )Z, integerPP, integerN0IN, double precisionDMIN,…
NAME dlasq3.f – SYNOPSIS Functions/Subroutines subroutine dlasq3 (I0, N0, Z, PP, DMIN, SIGMA, DESIG, QMAX, NFAIL, ITER, NDIV, IEEE, TTYPE, DMIN1, DMIN2, DN, DN1, DN2, G, TAU) DLASQ3 checks for deflation, computes a shift and calls dqds. Used by sbdsqr. Function/Subroutine Documentation subroutine dlasq3 (integerI0, integerN0, double precision, dimension( * )Z, integerPP, double precisionDMIN, double…
NAME dlasq2.f – SYNOPSIS Functions/Subroutines subroutine dlasq2 (N, Z, INFO) DLASQ2 computes all the eigenvalues of the symmetric positive definite tridiagonal matrix associated with the qd Array Z to high relative accuracy. Used by sbdsqr and sstegr. Function/Subroutine Documentation subroutine dlasq2 (integerN, double precision, dimension( * )Z, integerINFO) DLASQ2 computes all the eigenvalues of the…
NAME dlasq1.f – SYNOPSIS Functions/Subroutines subroutine dlasq1 (N, D, E, WORK, INFO) DLASQ1 computes the singular values of a real square bidiagonal matrix. Used by sbdsqr. Function/Subroutine Documentation subroutine dlasq1 (integerN, double precision, dimension( * )D, double precision, dimension( * )E, double precision, dimension( * )WORK, integerINFO) DLASQ1 computes the singular values of a real…
NAME dlaset.f – SYNOPSIS Functions/Subroutines subroutine dlaset (UPLO, M, N, ALPHA, BETA, A, LDA) DLASET initializes the off-diagonal elements and the diagonal elements of a matrix to given values. Function/Subroutine Documentation subroutine dlaset (characterUPLO, integerM, integerN, double precisionALPHA, double precisionBETA, double precision, dimension( lda, * )A, integerLDA) DLASET initializes the off-diagonal elements and the diagonal…
NAME dlasdt.f – SYNOPSIS Functions/Subroutines subroutine dlasdt (N, LVL, ND, INODE, NDIML, NDIMR, MSUB) DLASDT creates a tree of subproblems for bidiagonal divide and conquer. Used by sbdsdc. Function/Subroutine Documentation subroutine dlasdt (integerN, integerLVL, integerND, integer, dimension( * )INODE, integer, dimension( * )NDIML, integer, dimension( * )NDIMR, integerMSUB) DLASDT creates a tree of subproblems for…