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

6       CGBTRS - a system of linear equations  A * X = B, A**T * X = B, or A**H
7       * X = B with a general band matrix A using the  LU  factorization  com‐
8       puted by CGBTRF
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SYNOPSIS

11       SUBROUTINE CGBTRS( TRANS, N, KL, KU, NRHS, AB, LDAB, IPIV, B, LDB, INFO
12                          )
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14           CHARACTER      TRANS
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16           INTEGER        INFO, KL, KU, LDAB, LDB, N, NRHS
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18           INTEGER        IPIV( * )
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20           COMPLEX        AB( LDAB, * ), B( LDB, * )
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PURPOSE

23       CGBTRS solves a system of linear equations
24          A * X = B,  A**T * X = B,  or  A**H * X =  B  with  a  general  band
25       matrix A using the LU factorization computed by CGBTRF.
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ARGUMENTS

29       TRANS   (input) CHARACTER*1
30               Specifies the form of the system of equations.  = 'N':  A * X =
31               B     (No transpose)
32               = 'T':  A**T * X = B  (Transpose)
33               = 'C':  A**H * X = B  (Conjugate transpose)
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35       N       (input) INTEGER
36               The order of the matrix A.  N >= 0.
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38       KL      (input) INTEGER
39               The number of subdiagonals within the band of A.  KL >= 0.
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41       KU      (input) INTEGER
42               The number of superdiagonals within the band of A.  KU >= 0.
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44       NRHS    (input) INTEGER
45               The number of right hand sides, i.e., the number of columns  of
46               the matrix B.  NRHS >= 0.
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48       AB      (input) COMPLEX array, dimension (LDAB,N)
49               Details  of  the LU factorization of the band matrix A, as com‐
50               puted by CGBTRF.  U is  stored  as  an  upper  triangular  band
51               matrix  with KL+KU superdiagonals in rows 1 to KL+KU+1, and the
52               multipliers used during the factorization are  stored  in  rows
53               KL+KU+2 to 2*KL+KU+1.
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55       LDAB    (input) INTEGER
56               The leading dimension of the array AB.  LDAB >= 2*KL+KU+1.
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58       IPIV    (input) INTEGER array, dimension (N)
59               The  pivot  indices;  for  1 <= i <= N, row i of the matrix was
60               interchanged with row IPIV(i).
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62       B       (input/output) COMPLEX array, dimension (LDB,NRHS)
63               On entry, the right hand side matrix B.  On exit, the  solution
64               matrix X.
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66       LDB     (input) INTEGER
67               The leading dimension of the array B.  LDB >= max(1,N).
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69       INFO    (output) INTEGER
70               = 0:  successful exit
71               < 0:  if INFO = -i, the i-th argument had an illegal value
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75 LAPACK routine (version 3.1)    November 2006                       CGBTRS(1)
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