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

6       CPTSV  -  computes the solution to a complex system of linear equations
7       A*X = B, where A is an N-by-N Hermitian positive  definite  tridiagonal
8       matrix, and X and B are N-by-NRHS matrices
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SYNOPSIS

11       SUBROUTINE CPTSV( N, NRHS, D, E, B, LDB, INFO )
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13           INTEGER       INFO, LDB, N, NRHS
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15           REAL          D( * )
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17           COMPLEX       B( LDB, * ), E( * )
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PURPOSE

20       CPTSV computes the solution to a complex system of linear equations A*X
21       = B, where A is  an  N-by-N  Hermitian  positive  definite  tridiagonal
22       matrix,  and  X  and  B  are  N-by-NRHS matrices.  A is factored as A =
23       L*D*L**H, and the factored form of A is then used to solve  the  system
24       of equations.
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ARGUMENTS

27       N       (input) INTEGER
28               The order of the matrix A.  N >= 0.
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30       NRHS    (input) INTEGER
31               The  number of right hand sides, i.e., the number of columns of
32               the matrix B.  NRHS >= 0.
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34       D       (input/output) REAL array, dimension (N)
35               On entry, the n diagonal elements of the tridiagonal matrix  A.
36               On  exit, the n diagonal elements of the diagonal matrix D from
37               the factorization A = L*D*L**H.
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39       E       (input/output) COMPLEX array, dimension (N-1)
40               On entry, the (n-1) subdiagonal  elements  of  the  tridiagonal
41               matrix  A.  On exit, the (n-1) subdiagonal elements of the unit
42               bidiagonal factor L from the L*D*L**H factorization  of  A.   E
43               can  also be regarded as the superdiagonal of the unit bidiago‐
44               nal factor U from the U**H*D*U factorization of A.
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46       B       (input/output) COMPLEX array, dimension (LDB,NRHS)
47               On entry, the N-by-NRHS right hand side matrix B.  On exit,  if
48               INFO = 0, the N-by-NRHS solution matrix X.
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50       LDB     (input) INTEGER
51               The leading dimension of the array B.  LDB >= max(1,N).
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53       INFO    (output) INTEGER
54               = 0:  successful exit
55               < 0:  if INFO = -i, the i-th argument had an illegal value
56               > 0:  if INFO = i, the leading minor of order i is not positive
57               definite, and the solution has not been computed.  The  factor‐
58               ization has not been completed unless i = N.
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62 LAPACK routine (version 3.2)    November 2008                        CPTSV(1)
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