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

6       SPBTRS - a system of linear equations A*X = B with a symmetric positive
7       definite band matrix A using the Cholesky factorization A = U**T*U or A
8       = L*L**T computed by SPBTRF
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SYNOPSIS

11       SUBROUTINE SPBTRS( UPLO, N, KD, NRHS, AB, LDAB, B, LDB, INFO )
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13           CHARACTER      UPLO
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15           INTEGER        INFO, KD, LDAB, LDB, N, NRHS
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17           REAL           AB( LDAB, * ), B( LDB, * )
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PURPOSE

20       SPBTRS  solves  a  system  of linear equations A*X = B with a symmetric
21       positive definite band matrix A using the Cholesky  factorization  A  =
22       U**T*U or A = L*L**T computed by SPBTRF.
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ARGUMENTS

26       UPLO    (input) CHARACTER*1
27               = 'U':  Upper triangular factor stored in AB;
28               = 'L':  Lower triangular factor stored in AB.
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30       N       (input) INTEGER
31               The order of the matrix A.  N >= 0.
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33       KD      (input) INTEGER
34               The  number of superdiagonals of the matrix A if UPLO = 'U', or
35               the number of subdiagonals if UPLO = 'L'.  KD >= 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       AB      (input) REAL array, dimension (LDAB,N)
42               The  triangular factor U or L from the Cholesky factorization A
43               = U**T*U or A = L*L**T of the band  matrix  A,  stored  in  the
44               first  KD+1  rows  of  the array.  The j-th column of U or L is
45               stored in the j-th column of the array AB as follows:  if  UPLO
46               ='U',  AB(kd+1+i-j,j)  =  U(i,j) for max(1,j-kd)<=i<=j; if UPLO
47               ='L', AB(1+i-j,j)    = L(i,j) for j<=i<=min(n,j+kd).
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49       LDAB    (input) INTEGER
50               The leading dimension of the array AB.  LDAB >= KD+1.
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52       B       (input/output) REAL array, dimension (LDB,NRHS)
53               On entry, the right hand side matrix B.  On exit, the  solution
54               matrix X.
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56       LDB     (input) INTEGER
57               The leading dimension of the array B.  LDB >= max(1,N).
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59       INFO    (output) INTEGER
60               = 0:  successful exit
61               < 0:  if INFO = -i, the i-th argument had an illegal value
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65 LAPACK routine (version 3.1)    November 2006                       SPBTRS(1)
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