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

6       DGETRS  -  a system of linear equations  A * X = B or A' * X = B with a
7       general N-by-N matrix A using the LU factorization computed by DGETRF
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SYNOPSIS

10       SUBROUTINE DGETRS( TRANS, N, NRHS, A, LDA, IPIV, B, LDB, INFO )
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12           CHARACTER      TRANS
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14           INTEGER        INFO, LDA, LDB, N, NRHS
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16           INTEGER        IPIV( * )
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18           DOUBLE         PRECISION A( LDA, * ), B( LDB, * )
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PURPOSE

21       DGETRS solves a system of linear equations
22          A * X = B  or  A' * X = B with a general N-by-N matrix A  using  the
23       LU factorization computed by DGETRF.
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ARGUMENTS

27       TRANS   (input) CHARACTER*1
28               Specifies the form of the system of equations:
29               = 'N':  A * X = B  (No transpose)
30               = 'T':  A'* X = B  (Transpose)
31               = 'C':  A'* X = B  (Conjugate transpose = Transpose)
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33       N       (input) INTEGER
34               The order of the 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       A       (input) DOUBLE PRECISION array, dimension (LDA,N)
41               The factors L and U from the factorization A =  P*L*U  as  com‐
42               puted by DGETRF.
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44       LDA     (input) INTEGER
45               The leading dimension of the array A.  LDA >= max(1,N).
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47       IPIV    (input) INTEGER array, dimension (N)
48               The pivot indices from DGETRF; for 1<=i<=N, row i of the matrix
49               was interchanged with row IPIV(i).
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51       B       (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
52               On entry, the right hand side matrix B.  On exit, the  solution
53               matrix 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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58       INFO    (output) INTEGER
59               = 0:  successful exit
60               < 0:  if INFO = -i, the i-th argument had an illegal value
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64 LAPACK routine (version 3.1)    November 2006                       DGETRS(1)
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