SLA_GBRPVGRW computes the reciprocal pivot growth factor


 norm(A)/norm(U). The "max absolute element" norm is used. If this is


 much less than 1, the stability of the LU factorization of the


 (equilibrated) matrix A could be poor. This also means that the


 solution X, estimated condition numbers, and error bounds could be


 unreliable.

N

          N is INTEGER


     The number of linear equations, i.e., the order of the


     matrix A.  N >= 0.

KL

          KL is INTEGER


     The number of subdiagonals within the band of A.  KL >= 0.

KU

          KU is INTEGER


     The number of superdiagonals within the band of A.  KU >= 0.

NCOLS

          NCOLS is INTEGER


     The number of columns of the matrix A.  NCOLS >= 0.

AB

          AB is REAL array, dimension (LDAB,N)


     On entry, the matrix A in band storage, in rows 1 to KL+KU+1.


     The j-th column of A is stored in the j-th column of the


     array AB as follows:


     AB(KU+1+i-j,j) = A(i,j) for max(1,j-KU)<=i<=min(N,j+kl)

LDAB

          LDAB is INTEGER


     The leading dimension of the array AB.  LDAB >= KL+KU+1.

AFB

          AFB is REAL array, dimension (LDAFB,N)


     Details of the LU factorization of the band matrix A, as


     computed by SGBTRF.  U is stored as an upper triangular


     band matrix with KL+KU superdiagonals in rows 1 to KL+KU+1,


     and the multipliers used during the factorization are stored


     in rows KL+KU+2 to 2*KL+KU+1.

LDAFB

          LDAFB is INTEGER


     The leading dimension of the array AFB.  LDAFB >= 2*KL+KU+1.

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NAG Ltd.

December 2016