1ZGTTS2(1)           LAPACK auxiliary routine (version 3.1)           ZGTTS2(1)
2
3
4

NAME

6       ZGTTS2  -  one of the systems of equations  A * X = B, A**T * X = B, or
7       A**H * X = B,
8

SYNOPSIS

10       SUBROUTINE ZGTTS2( ITRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB )
11
12           INTEGER        ITRANS, LDB, N, NRHS
13
14           INTEGER        IPIV( * )
15
16           COMPLEX*16     B( LDB, * ), D( * ), DL( * ), DU( * ), DU2( * )
17

PURPOSE

19       ZGTTS2 solves one of the systems of equations
20          A * X = B,  A**T * X = B,  or  A**H * X  =  B,  with  a  tridiagonal
21       matrix A using the LU factorization computed by ZGTTRF.
22
23

ARGUMENTS

25       ITRANS  (input) INTEGER
26               Specifies the form of the system of equations.  = 0:  A * X = B
27               (No transpose)
28               = 1:  A**T * X = B  (Transpose)
29               = 2:  A**H * X = B  (Conjugate transpose)
30
31       N       (input) INTEGER
32               The order of the matrix A.
33
34       NRHS    (input) INTEGER
35               The number of right hand sides, i.e., the number of columns  of
36               the matrix B.  NRHS >= 0.
37
38       DL      (input) COMPLEX*16 array, dimension (N-1)
39               The (n-1) multipliers that define the matrix L from the LU fac‐
40               torization of A.
41
42       D       (input) COMPLEX*16 array, dimension (N)
43               The n diagonal elements of the upper triangular matrix  U  from
44               the LU factorization of A.
45
46       DU      (input) COMPLEX*16 array, dimension (N-1)
47               The (n-1) elements of the first super-diagonal of U.
48
49       DU2     (input) COMPLEX*16 array, dimension (N-2)
50               The (n-2) elements of the second super-diagonal of U.
51
52       IPIV    (input) INTEGER array, dimension (N)
53               The  pivot  indices;  for  1 <= i <= n, row i of the matrix was
54               interchanged with row IPIV(i).  IPIV(i) will always be either i
55               or  i+1;  IPIV(i)  =  i  indicates  a  row  interchange was not
56               required.
57
58       B       (input/output) COMPLEX*16 array, dimension (LDB,NRHS)
59               On entry, the matrix of right hand side vectors B.  On exit,  B
60               is overwritten by the solution vectors X.
61
62       LDB     (input) INTEGER
63               The leading dimension of the array B.  LDB >= max(1,N).
64
65
66
67 LAPACK auxiliary routine (versionNo3v.e1m)ber 2006                       ZGTTS2(1)
Impressum