gtts2 - gtts2: triangular solve using factor

Generated automatically by Doxygen for LAPACK from the source code. Version 3.12.0 Thu Aug 7 2025 17:26:25 gtts2(3)

subroutinecgtts2(integeritrans,integern,integernrhs,complex,dimension(*)dl,complex,dimension(*)d,complex,dimension(*)du,complex,dimension(*)du2,integer,dimension(*)ipiv,complex,dimension(ldb,*)b,integerldb)CGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf. Purpose: CGTTS2 solves one of the systems of equations A * X = B, A**T * X = B, or A**H * X = B, with a tridiagonal matrix A using the LU factorization computed by CGTTRF. ParametersITRANS 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**H * X = B (Conjugate transpose) N N is INTEGER The order of the matrix A. NRHS NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. DL DL is COMPLEX array, dimension (N-1) The (n-1) multipliers that define the matrix L from the LU factorization of A. D D is COMPLEX array, dimension (N) The n diagonal elements of the upper triangular matrix U from the LU factorization of A. DU DU is COMPLEX array, dimension (N-1) The (n-1) elements of the first super-diagonal of U. DU2 DU2 is COMPLEX array, dimension (N-2) The (n-2) elements of the second super-diagonal of U. IPIV 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 B is COMPLEX 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 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. subroutinedgtts2(integeritrans,integern,integernrhs,doubleprecision,dimension(*)dl,doubleprecision,dimension(*)d,doubleprecision,dimension(*)du,doubleprecision,dimension(*)du2,integer,dimension(*)ipiv,doubleprecision,dimension(ldb,*)b,integerldb)DGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf. Purpose: DGTTS2 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 DGTTRF. ParametersITRANS 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 N is INTEGER The order of the matrix A. NRHS NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. DL DL is DOUBLE PRECISION array, dimension (N-1) The (n-1) multipliers that define the matrix L from the LU factorization of A. D D is DOUBLE PRECISION array, dimension (N) The n diagonal elements of the upper triangular matrix U from the LU factorization of A. DU DU is DOUBLE PRECISION array, dimension (N-1) The (n-1) elements of the first super-diagonal of U. DU2 DU2 is DOUBLE PRECISION array, dimension (N-2) The (n-2) elements of the second super-diagonal of U. IPIV 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 B is DOUBLE PRECISION 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 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. subroutinesgtts2(integeritrans,integern,integernrhs,real,dimension(*)dl,real,dimension(*)d,real,dimension(*)du,real,dimension(*)du2,integer,dimension(*)ipiv,real,dimension(ldb,*)b,integerldb)SGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf. 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. ParametersITRANS 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 N is INTEGER The order of the matrix A. NRHS NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. DL DL is REAL array, dimension (N-1) The (n-1) multipliers that define the matrix L from the LU factorization of A. D D is REAL array, dimension (N) The n diagonal elements of the upper triangular matrix U from the LU factorization of A. DU DU is REAL array, dimension (N-1) The (n-1) elements of the first super-diagonal of U. DU2 DU2 is REAL array, dimension (N-2) The (n-2) elements of the second super-diagonal of U. IPIV 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 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 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. subroutinezgtts2(integeritrans,integern,integernrhs,complex*16,dimension(*)dl,complex*16,dimension(*)d,complex*16,dimension(*)du,complex*16,dimension(*)du2,integer,dimension(*)ipiv,complex*16,dimension(ldb,*)b,integerldb)ZGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf. Purpose: ZGTTS2 solves one of the systems of equations A * X = B, A**T * X = B, or A**H * X = B, with a tridiagonal matrix A using the LU factorization computed by ZGTTRF. ParametersITRANS 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**H * X = B (Conjugate transpose) N N is INTEGER The order of the matrix A. NRHS NRHS is INTEGER The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. DL DL is COMPLEX*16 array, dimension (N-1) The (n-1) multipliers that define the matrix L from the LU factorization of A. D D is COMPLEX*16 array, dimension (N) The n diagonal elements of the upper triangular matrix U from the LU factorization of A. DU DU is COMPLEX*16 array, dimension (N-1) The (n-1) elements of the first super-diagonal of U. DU2 DU2 is COMPLEX*16 array, dimension (N-2) The (n-2) elements of the second super-diagonal of U. IPIV 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 B is COMPLEX*16 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 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.

gtts2 - gtts2: triangular solve using factor

Functions subroutine cgtts2 (itrans, n, nrhs, dl, d, du, du2, ipiv, b, ldb) CGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf. subroutine dgtts2 (itrans, n, nrhs, dl, d, du, du2, ipiv, b, ldb) DGTTS2 solves 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) SGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf. subroutine zgtts2 (itrans, n, nrhs, dl, d, du, du2, ipiv, b, ldb) ZGTTS2 solves a system of linear equations with a tridiagonal matrix using the LU factorization computed by sgttrf.