XLPack 7.0
XLPack Numerical Library (C API) Reference Manual
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◆ csr_zussv()

void csr_zussv ( char  uplo,
char  trans,
char  diag,
int  n,
const doublecomplex  val[],
const int  rowptr[],
const int  colind[],
int  base,
doublecomplex  x[],
int  incx,
int *  info 
)

Solution of Ax = b, ATx = b or AHx = b (Complex triangular matrices) (CSR)

Purpose
This function solves one of the following systems of equations for a sparse matrix in CSR format.
A*x = b, A^T*x = b or A^H*x = b
where b and x are n element vectors and A is an n x n upper or lower sparse triangular matrix.
Parameters
[in]uploSpecifies whether the matrix is an upper or lower triangular matrix as follows:
= 'U': A is an upper triangular matrix.
= 'L': A is an lower triangular matrix.
The other triangular elements (not including diagonal elements) are ignored.
[in]transSpecifies the equation to be solved as follows:
= 'N': A*x = b.
= 'T': A^T*x = b.
= 'C': A^H*x = b.
[in]diagSpecifies whether or not A is assumed to be unit triangular.
= 'N': A is not assumed to be unit triangular.
= 'U': A is assumed to be unit triangular. (diagonal elements are assumed to be ones. Elements of val[] at diagonal element positions (if exist) are ignored.)
[in]nNumber of rows and columns of matrix A. (n >= 0) (If n = 0, returns without computation)
[in]val[]Array val[lval] (lval >= nnz)
Values of nonzero elements of matrix A (where nnz is the number of nonzero elements).
[in]rowptr[]Array rowptr[lrowptr] (lrowptr >= n + 1)
Row pointers of matrix A.
[in]colind[]Array colind[lcolind] (lcolind >= nnz)
Column indices of matrix A (where nnz is the number of nonzero elements).
[in]baseIndexing of rowptr[] and colind[].
= 0: Zero-based (C style) indexing: Starting index is 0.
= 1: One-based (Fortran style) indexing: Starting index is 1.
[in,out]x[]Array x[lx] (lx >= 1 + (n - 1)*incx)
[in] Right-hand side vector b.
[out] Solution vector x.
[in]incxStorage spacing between elements of x[].
[out]info= 0: Successful exit.
= i < 0: The (-i)-th argument is invalid.
= i > 0: The matrix is singular (i-th diagonal element is zero).