sgtts2 - solve a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf
SUBROUTINE SGTTS2(ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB) INTEGER ITRANS, LDB, N, NRHS INTEGER IPIV(*) REAL B(LDB,*), D(*), DL(*), DU(*), DU2(*) SUBROUTINE SGTTS2_64(ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB) INTEGER*8 ITRANS, LDB, N, NRHS INTEGER*8 IPIV(*) REAL B(LDB,*), D(*), DL(*), DU(*), DU2(*) F95 INTERFACE SUBROUTINE GTTS2(ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB) REAL, DIMENSION(:,:) :: B INTEGER :: ITRANS, N, NRHS, LDB INTEGER, DIMENSION(:) :: IPIV REAL, DIMENSION(:) :: DL, D, DU, DU2 SUBROUTINE GTTS2_64(ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB) REAL, DIMENSION(:,:) :: B INTEGER(8) :: ITRANS, N, NRHS, LDB INTEGER(8), DIMENSION(:) :: IPIV REAL, DIMENSION(:) :: DL, D, DU, DU2 C INTERFACE #include <sunperf.h> void sgtts2 (int itrans, int n, int nrhs, float *dl, float *d, float *du, float *du2, int *ipiv, float *b, int ldb); void sgtts2_64 (long itrans, long n, long nrhs, float *dl, float *d, float *du, float *du2, long *ipiv, float *b, long ldb);
Oracle Solaris Studio Performance Library sgtts2(3P) NAME sgtts2 - solve a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf SYNOPSIS SUBROUTINE SGTTS2(ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB) INTEGER ITRANS, LDB, N, NRHS INTEGER IPIV(*) REAL B(LDB,*), D(*), DL(*), DU(*), DU2(*) SUBROUTINE SGTTS2_64(ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB) INTEGER*8 ITRANS, LDB, N, NRHS INTEGER*8 IPIV(*) REAL B(LDB,*), D(*), DL(*), DU(*), DU2(*) F95 INTERFACE SUBROUTINE GTTS2(ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB) REAL, DIMENSION(:,:) :: B INTEGER :: ITRANS, N, NRHS, LDB INTEGER, DIMENSION(:) :: IPIV REAL, DIMENSION(:) :: DL, D, DU, DU2 SUBROUTINE GTTS2_64(ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB) REAL, DIMENSION(:,:) :: B INTEGER(8) :: ITRANS, N, NRHS, LDB INTEGER(8), DIMENSION(:) :: IPIV REAL, DIMENSION(:) :: DL, D, DU, DU2 C INTERFACE #include <sunperf.h> void sgtts2 (int itrans, int n, int nrhs, float *dl, float *d, float *du, float *du2, int *ipiv, float *b, int ldb); void sgtts2_64 (long itrans, long n, long nrhs, float *dl, float *d, float *du, float *du2, long *ipiv, float *b, long ldb); PURPOSE sgtts2 solves one of the systems of equations A*X=B or A**T*X=B, with a tridiagonal matrix A using the LU factorization computed by SGTTRF ARGUMENTS ITRANS (input) ITRANS is INTEGER Specifies the form of the system of equations. = 0: A * X = B (No transpose), = 1: A**T* X = B (Transpose), = 2: A**T* X = B (Conjugate transpose = Transpose). N (input) N is INTEGER The order of the matrix A. NRHS (input) NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. DL (input) DL is REAL array, dimension (N-1) The (N-1) multipliers that define the matrix L from the LU factorization of A. D (input) D is REAL array, dimension (N) The n diagonal elements of the upper triangular matrix U from the LU factorization of A. DU (input) DU is REAL array, dimension (N-1) The (N-1) elements of the first super-diagonal of U. DU2 (input) DU2 is REAL array, dimension (N-2) The (N-2) elements of the second super-diagonal of U. IPIV (input) IPIV is INTEGER array, dimension (N) The pivot indices; for 1 <= i <= N, row i of the matrix was interchanged with row IPIV(i). IPIV(i) will always be either i or i+1; IPIV(i) = i indicates a row interchange was not required. B (input/output) B is REAL array, dimension (LDB,NRHS) On entry, the matrix of right hand side vectors B. On exit, B is overwritten by the solution vectors X. LDB (input) LDB is INTEGER The leading dimension of the array B. LDB >= max(1,N). 7 Nov 2015 sgtts2(3P)