1ZPTTS2(1)                LAPACK routine (version 3.1)                ZPTTS2(1)
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NAME

6       ZPTTS2  - a tridiagonal system of the form  A * X = B using the factor‐
7       ization A = U'*D*U or A = L*D*L' computed by ZPTTRF
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SYNOPSIS

10       SUBROUTINE ZPTTS2( IUPLO, N, NRHS, D, E, B, LDB )
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12           INTEGER        IUPLO, LDB, N, NRHS
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14           DOUBLE         PRECISION D( * )
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16           COMPLEX*16     B( LDB, * ), E( * )
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PURPOSE

19       ZPTTS2 solves a tridiagonal system of the form
20          A * X = B using the factorization A = U'*D*U or A = L*D*L'  computed
21       by  ZPTTRF.  D is a diagonal matrix specified in the vector D, U (or L)
22       is a unit bidiagonal matrix whose superdiagonal (subdiagonal) is speci‐
23       fied in the vector E, and X and B are N by NRHS matrices.
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ARGUMENTS

27       IUPLO   (input) INTEGER
28               Specifies  the form of the factorization and whether the vector
29               E is the superdiagonal of the upper bidiagonal factor U or  the
30               subdiagonal  of  the  lower  bidiagonal  factor  L.   = 1:  A =
31               U'*D*U, E is the superdiagonal of U
32               = 0:  A = L*D*L', E is the subdiagonal of L
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34       N       (input) INTEGER
35               The order of the tridiagonal matrix A.  N >= 0.
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37       NRHS    (input) INTEGER
38               The number of right hand sides, i.e., the number of columns  of
39               the matrix B.  NRHS >= 0.
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41       D       (input) DOUBLE PRECISION array, dimension (N)
42               The  n diagonal elements of the diagonal matrix D from the fac‐
43               torization A = U'*D*U or A = L*D*L'.
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45       E       (input) COMPLEX*16 array, dimension (N-1)
46               If IUPLO = 1, the (n-1)  superdiagonal  elements  of  the  unit
47               bidiagonal  factor  U  from  the  factorization A = U'*D*U.  If
48               IUPLO = 0, the (n-1) subdiagonal elements of the unit  bidiago‐
49               nal factor L from the factorization A = L*D*L'.
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51       B       (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
52               On  entry, the right hand side vectors B for the system of lin‐
53               ear equations.  On exit, the solution vectors, X.
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55       LDB     (input) INTEGER
56               The leading dimension of the array B.  LDB >= max(1,N).
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60 LAPACK routine (version 3.1)    November 2006                       ZPTTS2(1)
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