CLA_GBRCOND_X (3) Linux Manual Page

cla_gbrcond_x.f –

Synopsis

Functions/Subroutines

REAL function cla_gbrcond_x (TRANS, N, KL, KU, AB, LDAB, AFB, LDAFB, IPIV, X, INFO, WORK, RWORK)
CLA_GBRCOND_X computes the infinity norm condition number of op(A)*diag(x) for general banded matrices.

Function/Subroutine Documentation

REAL function cla_gbrcond_x (characterTRANS, integerN, integerKL, integerKU, complex, dimension( ldab, * )AB, integerLDAB, complex, dimension( ldafb, * )AFB, integerLDAFB, integer, dimension( * )IPIV, complex, dimension( * )X, integerINFO, complex, dimension( * )WORK, real, dimension( * )RWORK)

CLA_GBRCOND_X computes the infinity norm condition number of op(A)*diag(x) for general banded matrices.

Purpose:

 CLA_GBRCOND_X Computes the infinity norm condition number of

 op(A) * diag(X) where X is a COMPLEX 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).

X

 X is COMPLEX array, dimension (N)

 The vector X in the formula op(A) * diag(X).

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:

September 2012

Definition at line 153 of file cla_gbrcond_x.f.

Author

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