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template<typename T>
void gttrs(char *trans, integer *n, integer *nrhs, T *dl, T *d, T *du, T *du2, integer *ipiv, T *b, integer *ldb, integer *info)# GTTRS solves one of the systems of equations.
Purpose:
GTTRS 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.
- Parameters:
TRANS – [in]
TRANS is CHARACTER*1
Specifies the form of the system of equations.
= ‘N’: A * X = B (No transpose)
= ‘T’: A**T* X = B (Transpose)
= ‘C’: A**T* X = B (Conjugate transpose = Transpose)N – [in]
N is INTEGER
The order of the matrix A.
NRHS – [in]
NRHS is INTEGER
The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
DL – [in]
DL is REAL array, dimension (N-1)
The (n-1) multipliers that define the matrix L from the LU factorization of A.
D – [in]
D is REAL array, dimension (N)
The n diagonal elements of the upper triangular matrix U from the LU factorization of A.
DU – [in]
DU is REAL array, dimension (N-1)
The (n-1) elements of the first super-diagonal of U.
DU2 – [in]
DU2 is REAL array, dimension (N-2)
The (n-2) elements of the second super-diagonal of U.
IPIV – [in]
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 – [inout]
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 – [in]
LDB is INTEGER
The leading dimension of the array B. LDB >= fla_max(1,N).
INFO – [out]
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value