.TH "SRC/sla_gbrcond.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/sla_gbrcond.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "real function \fBsla_gbrcond\fP (trans, n, kl, ku, ab, ldab, afb, ldafb, ipiv, cmode, c, info, work, iwork)"
.br
.RI "\fBSLA_GBRCOND\fP estimates the Skeel condition number for a general banded matrix\&. "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "real function sla_gbrcond (character trans, integer n, integer kl, integer ku, real, dimension( ldab, * ) ab, integer ldab, real, dimension( ldafb, * ) afb, integer ldafb, integer, dimension( * ) ipiv, integer cmode, real, dimension( * ) c, integer info, real, dimension( * ) work, integer, dimension( * ) iwork)"

.PP
\fBSLA_GBRCOND\fP estimates the Skeel condition number for a general banded matrix\&.  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
    SLA_GBRCOND Estimates the Skeel condition number of  op(A) * op2(C)
    where op2 is determined by CMODE as follows
    CMODE =  1    op2(C) = C
    CMODE =  0    op2(C) = I
    CMODE = -1    op2(C) = inv(C)
    The Skeel condition number  cond(A) = norminf( |inv(A)||A| )
    is computed by computing scaling factors R such that
    diag(R)*A*op2(C) is row equilibrated and computing the standard
    infinity-norm condition number\&.
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fITRANS\fP 
.PP
.nf
          TRANS is CHARACTER*1
     Specifies the form of the system of equations:
       = 'N':  A * X = B     (No transpose)
       = 'T':  A**T * X = B  (Transpose)
       = 'C':  A**H * X = B  (Conjugate Transpose = Transpose)
.fi
.PP
.br
\fIN\fP 
.PP
.nf
          N is INTEGER
     The number of linear equations, i\&.e\&., the order of the
     matrix A\&.  N >= 0\&.
.fi
.PP
.br
\fIKL\fP 
.PP
.nf
          KL is INTEGER
     The number of subdiagonals within the band of A\&.  KL >= 0\&.
.fi
.PP
.br
\fIKU\fP 
.PP
.nf
          KU is INTEGER
     The number of superdiagonals within the band of A\&.  KU >= 0\&.
.fi
.PP
.br
\fIAB\fP 
.PP
.nf
          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)
.fi
.PP
.br
\fILDAB\fP 
.PP
.nf
          LDAB is INTEGER
     The leading dimension of the array AB\&.  LDAB >= KL+KU+1\&.
.fi
.PP
.br
\fIAFB\fP 
.PP
.nf
          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\&.
.fi
.PP
.br
\fILDAFB\fP 
.PP
.nf
          LDAFB is INTEGER
     The leading dimension of the array AFB\&.  LDAFB >= 2*KL+KU+1\&.
.fi
.PP
.br
\fIIPIV\fP 
.PP
.nf
          IPIV is INTEGER array, dimension (N)
     The pivot indices from the factorization A = P*L*U
     as computed by SGBTRF; row i of the matrix was interchanged
     with row IPIV(i)\&.
.fi
.PP
.br
\fICMODE\fP 
.PP
.nf
          CMODE is INTEGER
     Determines op2(C) in the formula op(A) * op2(C) as follows:
     CMODE =  1    op2(C) = C
     CMODE =  0    op2(C) = I
     CMODE = -1    op2(C) = inv(C)
.fi
.PP
.br
\fIC\fP 
.PP
.nf
          C is REAL array, dimension (N)
     The vector C in the formula op(A) * op2(C)\&.
.fi
.PP
.br
\fIINFO\fP 
.PP
.nf
          INFO is INTEGER
       = 0:  Successful exit\&.
     i > 0:  The ith argument is invalid\&.
.fi
.PP
.br
\fIWORK\fP 
.PP
.nf
          WORK is REAL array, dimension (5*N)\&.
     Workspace\&.
.fi
.PP
.br
\fIIWORK\fP 
.PP
.nf
          IWORK is INTEGER array, dimension (N)\&.
     Workspace\&.
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 
.PP
Univ\&. of California Berkeley 
.PP
Univ\&. of Colorado Denver 
.PP
NAG Ltd\&. 
.RE
.PP

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Definition at line \fB166\fP of file \fBsla_gbrcond\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.