◆ zgttrs()

Solution to LU factorized system of linear equations AX = B, A^TX = B or A^HX = B for a complex tridiagonal matrix

Purpose: This routine solves one of the system 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.

Parameters

[in]	trans	Specifies the form of the system of equations: = 'N': A * X = B. (no transpose) = 'T': A^T * X = B. (transpose) = 'C': A^H * X = B. (conjugate transpose)
[in]	n	Order of the matrix A. (n >= 0) (If n = 0, returns without computation)
[in]	nrhs	Number of right hand sides, i.e., number of columns of the matrix B. (nrhs >= 0) (if nrhs = 0, returns without computation)
[in]	dl[]	Array dl[ldl] (ldl >= n - 1) n-1 multipliers that define the matrix L from the LU factorization of A.
[in]	d[]	Array d[ld] (ld >= n) n diagonal elements of the upper triangular matrix U from the LU factorization of A.
[in]	du[]	Array du[ldu] (ldu >= n - 1) n-1 elements of the first super-diagonal of U.
[in]	du2[]	Array du2[ldu2] (ldu2 >= n - 2) n-2 elements of the second super-diagonal of U.
[out]	ipiv[]	Array ipiv[lipiv] (lipiv >= n) Pivot indices; for 1 <= i <= n, row i of the matrix was interchanged with row ipiv[i-1]. ipiv[i-1] will always be either i or i+1; ipiv[i-1] = i indicates a row interchange was not required.
[in]	ldb	Leading dimension of the two dimensional array b[][]. (ldb >= max(1, n))
[in,out]	b[][]	Array b[lb][ldb] (lb >= nrhs) [in] Right hand side matrix B. [out] Solution matrix X.
[out]	info	= 0: Successful exit = -1: The argument trans had an illegal value (trans != 'N', 'T' nor 'C') = -2: The argument n had an illegal value (n < 0) = -3: The argument nrhs had an illegal value (nrhs < 0) = -9: The argument ldb had an illegal value (ldb < max(1, n))