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cla_gbrcond_c.f(3) LAPACK cla_gbrcond_c.f(3)

NAME

cla_gbrcond_c.f

SYNOPSIS

Functions/Subroutines


real function cla_gbrcond_c (TRANS, N, KL, KU, AB, LDAB, AFB, LDAFB, IPIV, C, CAPPLY, INFO, WORK, RWORK)
CLA_GBRCOND_C computes the infinity norm condition number of op(A)*inv(diag(c)) for general banded matrices.

Function/Subroutine Documentation

real function cla_gbrcond_c (character TRANS, integer N, integer KL, integer KU, complex, dimension( ldab, * ) AB, integer LDAB, complex, dimension( ldafb, * ) AFB, integer LDAFB, integer, dimension( * ) IPIV, real, dimension( * ) C, logical CAPPLY, integer INFO, complex, dimension( * ) WORK, real, dimension( * ) RWORK)

CLA_GBRCOND_C computes the infinity norm condition number of op(A)*inv(diag(c)) for general banded matrices.

Purpose:


CLA_GBRCOND_C Computes the infinity norm condition number of
op(A) * inv(diag(C)) where C is a REAL vector.

Parameters:

TRANS


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)

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.

AB


AB is COMPLEX 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 COMPLEX array, dimension (LDAFB,N)
Details of the LU factorization of the band matrix A, as
computed by CGBTRF. 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.

IPIV


IPIV is INTEGER array, dimension (N)
The pivot indices from the factorization A = P*L*U
as computed by CGBTRF; row i of the matrix was interchanged
with row IPIV(i).

C


C is REAL array, dimension (N)
The vector C in the formula op(A) * inv(diag(C)).

CAPPLY


CAPPLY is LOGICAL
If .TRUE. then access the vector C in the formula above.

INFO


INFO is INTEGER
= 0: Successful exit.
i > 0: The ith argument is invalid.

WORK


WORK is COMPLEX array, dimension (2*N).
Workspace.

RWORK


RWORK is REAL array, dimension (N).
Workspace.

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

December 2016

Definition at line 163 of file cla_gbrcond_c.f.

Author

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Tue Nov 14 2017 Version 3.8.0