1CPTTS2(1)                LAPACK routine (version 3.2)                CPTTS2(1)
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NAME

6       CPTTS2  -  solves a tridiagonal system of the form  A * X = B using the
7       factorization A = U'*D*U or A = L*D*L' computed by CPTTRF
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SYNOPSIS

10       SUBROUTINE CPTTS2( IUPLO, N, NRHS, D, E, B, LDB )
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12           INTEGER        IUPLO, LDB, N, NRHS
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14           REAL           D( * )
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16           COMPLEX        B( LDB, * ), E( * )
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PURPOSE

19       CPTTS2 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  CPTTRF.  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

26       IUPLO   (input) INTEGER
27               Specifies  the form of the factorization and whether the vector
28               E is the superdiagonal of the upper bidiagonal factor U or  the
29               subdiagonal  of  the  lower  bidiagonal  factor  L.   = 1:  A =
30               U'*D*U, E is the superdiagonal of U
31               = 0:  A = L*D*L', E is the subdiagonal of L
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33       N       (input) INTEGER
34               The order of the tridiagonal matrix A.  N >= 0.
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36       NRHS    (input) INTEGER
37               The number of right hand sides, i.e., the number of columns  of
38               the matrix B.  NRHS >= 0.
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40       D       (input) REAL array, dimension (N)
41               The  n diagonal elements of the diagonal matrix D from the fac‐
42               torization A = U'*D*U or A = L*D*L'.
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44       E       (input) COMPLEX array, dimension (N-1)
45               If IUPLO = 1, the (n-1)  superdiagonal  elements  of  the  unit
46               bidiagonal  factor  U  from  the  factorization A = U'*D*U.  If
47               IUPLO = 0, the (n-1) subdiagonal elements of the unit  bidiago‐
48               nal factor L from the factorization A = L*D*L'.
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50       B       (input/output) REAL array, dimension (LDB,NRHS)
51               On  entry, the right hand side vectors B for the system of lin‐
52               ear equations.  On exit, the solution vectors, X.
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54       LDB     (input) INTEGER
55               The leading dimension of the array B.  LDB >= max(1,N).
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59 LAPACK routine (version 3.2)    November 2008                       CPTTS2(1)
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