◆ WZtrtrs2()

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

Purpose: WZtrtrs2 solves a triangular system of the form
A * X = B, A^T * X = B or A^H * X = B

where A is a triangular matrix of order N and B is an N x Nrhs matrix. A check is made to verify that A is nonsingular.

To represent complex numbers, a real part and an imaginary part are stored in a pair of adjacent cells (a real part in a left cell, and an imaginary part in a right cell). The computed results are stored in the same way.

Returns

N+1 x 2Nrhs

	Column 1	Column 2	. . .	Column 2Nrhs
Rows 1 to N	Solution matrix X (a real part and an imaginary part are stored in a pair of adjacent columns (a real part is left and an imaginary part is right))
Row N+1	Reciprocal condition number	Return code	. . .	0

Return code.
= 0: Successful exit.
= i > 0: The i-th diagonal element of the factor is zero. (Matrix A is singular)

Parameters

[in]	Uplo	= "U": A is upper triangular matrix. = "L": A is lower triangular matrix.
[in]	N	Number of linear equations, i.e., order of the matrix A. (N >= 1)
[in]	A	(N x 2N) N x N coefficient matrix A. (If Uplo = 0, the lower triangular part will be used. If Uplo = 1, the upper triangular part will be used)
[in]	B	(N x 2Nrhs) N x Nrhs right hand side matrix B.
[in]	Trans	(Optional) Specifies the form of the system of equations. (default = "N") = "N": A * X = B. (no transpose) = "T": A^T * X = B. (transpose) = "C": A^H * X = B. (conjugate transpose)
[in]	Nrhs	(Optional) Number of columns of right hand side matrix B. (Nrhs >= 1) (default = 1)

Example: Solve the system of linear equations Ax = B and estimate the reciprocal of the condition number (RCond) of A, where A is a triangular matrix and
( 0.20-0.11i 0 0 )

A = ( -0.93-0.32i 0.81+0.37i 0 )

( -0.80-0.92i -0.29+0.86i 0.64+0.51i )

( 0.2069+0.0399i )

B = ( -0.6633-0.6775i )

( -0.4965-0.6057i )

WZtrtrs2