ptts2 - ptts2: triangular solve using factor, unblocked

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subroutinecptts2(integeriuplo,integern,integernrhs,real,dimension(*)d,complex,dimension(*)e,complex,dimension(ldb,*)b,integerldb)CPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. Purpose: CPTTS2 solves a tridiagonal system of the form A * X = B using the factorization A = U**H*D*U or A = L*D*L**H computed by CPTTRF. D is a diagonal matrix specified in the vector D, U (or L) is a unit bidiagonal matrix whose superdiagonal (subdiagonal) is specified in the vector E, and X and B are N by NRHS matrices. ParametersIUPLO IUPLO is INTEGER Specifies the form of the factorization and whether the vector E is the superdiagonal of the upper bidiagonal factor U or the subdiagonal of the lower bidiagonal factor L. = 1: A = U**H *D*U, E is the superdiagonal of U = 0: A = L*D*L**H, E is the subdiagonal of L N N is INTEGER The order of the tridiagonal matrix A. N >= 0. NRHS NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. D D is REAL array, dimension (N) The n diagonal elements of the diagonal matrix D from the factorization A = U**H *D*U or A = L*D*L**H. E E is COMPLEX array, dimension (N-1) If IUPLO = 1, the (n-1) superdiagonal elements of the unit bidiagonal factor U from the factorization A = U**H*D*U. If IUPLO = 0, the (n-1) subdiagonal elements of the unit bidiagonal factor L from the factorization A = L*D*L**H. B B is COMPLEX array, dimension (LDB,NRHS) On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, X. LDB LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutinedptts2(integern,integernrhs,doubleprecision,dimension(*)d,doubleprecision,dimension(*)e,doubleprecision,dimension(ldb,*)b,integerldb)DPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. Purpose: DPTTS2 solves a tridiagonal system of the form A * X = B using the L*D*L**T factorization of A computed by DPTTRF. D is a diagonal matrix specified in the vector D, L is a unit bidiagonal matrix whose subdiagonal is specified in the vector E, and X and B are N by NRHS matrices. ParametersN N is INTEGER The order of the tridiagonal matrix A. N >= 0. NRHS NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. D D is DOUBLE PRECISION array, dimension (N) The n diagonal elements of the diagonal matrix D from the L*D*L**T factorization of A. E E is DOUBLE PRECISION array, dimension (N-1) The (n-1) subdiagonal elements of the unit bidiagonal factor L from the L*D*L**T factorization of A. E can also be regarded as the superdiagonal of the unit bidiagonal factor U from the factorization A = U**T*D*U. B B is DOUBLE PRECISION array, dimension (LDB,NRHS) On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, X. LDB LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutinesptts2(integern,integernrhs,real,dimension(*)d,real,dimension(*)e,real,dimension(ldb,*)b,integerldb)SPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. Purpose: SPTTS2 solves a tridiagonal system of the form A * X = B using the L*D*L**T factorization of A computed by SPTTRF. D is a diagonal matrix specified in the vector D, L is a unit bidiagonal matrix whose subdiagonal is specified in the vector E, and X and B are N by NRHS matrices. ParametersN N is INTEGER The order of the tridiagonal matrix A. N >= 0. NRHS NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. D D is REAL array, dimension (N) The n diagonal elements of the diagonal matrix D from the L*D*L**T factorization of A. E E is REAL array, dimension (N-1) The (n-1) subdiagonal elements of the unit bidiagonal factor L from the L*D*L**T factorization of A. E can also be regarded as the superdiagonal of the unit bidiagonal factor U from the factorization A = U**T*D*U. B B is REAL array, dimension (LDB,NRHS) On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, X. LDB LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. subroutinezptts2(integeriuplo,integern,integernrhs,doubleprecision,dimension(*)d,complex*16,dimension(*)e,complex*16,dimension(ldb,*)b,integerldb)ZPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. Purpose: ZPTTS2 solves a tridiagonal system of the form A * X = B using the factorization A = U**H *D*U or A = L*D*L**H computed by ZPTTRF. D is a diagonal matrix specified in the vector D, U (or L) is a unit bidiagonal matrix whose superdiagonal (subdiagonal) is specified in the vector E, and X and B are N by NRHS matrices. ParametersIUPLO IUPLO is INTEGER Specifies the form of the factorization and whether the vector E is the superdiagonal of the upper bidiagonal factor U or the subdiagonal of the lower bidiagonal factor L. = 1: A = U**H *D*U, E is the superdiagonal of U = 0: A = L*D*L**H, E is the subdiagonal of L N N is INTEGER The order of the tridiagonal matrix A. N >= 0. NRHS NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. D D is DOUBLE PRECISION array, dimension (N) The n diagonal elements of the diagonal matrix D from the factorization A = U**H *D*U or A = L*D*L**H. E E is COMPLEX*16 array, dimension (N-1) If IUPLO = 1, the (n-1) superdiagonal elements of the unit bidiagonal factor U from the factorization A = U**H*D*U. If IUPLO = 0, the (n-1) subdiagonal elements of the unit bidiagonal factor L from the factorization A = L*D*L**H. B B is COMPLEX*16 array, dimension (LDB,NRHS) On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, X. LDB LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). Author Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.

ptts2 - ptts2: triangular solve using factor, unblocked

Functions subroutine cptts2 (iuplo, n, nrhs, d, e, b, ldb) CPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. subroutine dptts2 (n, nrhs, d, e, b, ldb) DPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. subroutine sptts2 (n, nrhs, d, e, b, ldb) SPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf. subroutine zptts2 (iuplo, n, nrhs, d, e, b, ldb) ZPTTS2 solves a tridiagonal system of the form AX=B using the L D LH factorization computed by spttrf.