# sla_lin_berr.f(3) [centos man page]

```sla_lin_berr.f(3)						      LAPACK							 sla_lin_berr.f(3)

NAME
sla_lin_berr.f -

SYNOPSIS
Functions/Subroutines
subroutine sla_lin_berr (N, NZ, NRHS, RES, AYB, BERR)
SLA_LIN_BERR computes a component-wise relative backward error.

Function/Subroutine Documentation
subroutine sla_lin_berr (integerN, integerNZ, integerNRHS, real, dimension( n, nrhs )RES, real, dimension( n, nrhs )AYB, real, dimension( nrhs
)BERR)
SLA_LIN_BERR computes a component-wise relative backward error.

Purpose:

SLA_LIN_BERR computes componentwise relative backward error from
the formula
max(i) ( abs(R(i)) / ( abs(op(A_s))*abs(Y) + abs(B_s) )(i) )
where abs(Z) is the componentwise absolute value of the matrix
or vector Z.

Parameters:
N

N is INTEGER
The number of linear equations, i.e., the order of the
matrix A.  N >= 0.

NZ

NZ is INTEGER
We add (NZ+1)*SLAMCH( 'Safe minimum' ) to R(i) in the numerator to
guard against spuriously zero residuals. Default value is N.

NRHS

NRHS is INTEGER
The number of right hand sides, i.e., the number of columns
of the matrices AYB, RES, and BERR.  NRHS >= 0.

RES

RES is REAL array, dimension (N,NRHS)
The residual matrix, i.e., the matrix R in the relative backward
error formula above.

AYB

AYB is REAL array, dimension (N, NRHS)
The denominator in the relative backward error formula above, i.e.,
the matrix abs(op(A_s))*abs(Y) + abs(B_s). The matrices A, Y, and B
are from iterative refinement (see sla_gerfsx_extended.f).

BERR

BERR is REAL array, dimension (NRHS)
The componentwise relative backward error from the formula above.

Author:
Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Date:
September 2012

Definition at line 102 of file sla_lin_berr.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						 sla_lin_berr.f(3)```

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```sla_lin_berr.f(3)						      LAPACK							 sla_lin_berr.f(3)

NAME
sla_lin_berr.f -

SYNOPSIS
Functions/Subroutines
subroutine sla_lin_berr (N, NZ, NRHS, RES, AYB, BERR)
SLA_LIN_BERR computes a component-wise relative backward error.

Function/Subroutine Documentation
subroutine sla_lin_berr (integerN, integerNZ, integerNRHS, real, dimension( n, nrhs )RES, real, dimension( n, nrhs )AYB, real, dimension( nrhs
)BERR)
SLA_LIN_BERR computes a component-wise relative backward error.

Purpose:

SLA_LIN_BERR computes componentwise relative backward error from
the formula
max(i) ( abs(R(i)) / ( abs(op(A_s))*abs(Y) + abs(B_s) )(i) )
where abs(Z) is the componentwise absolute value of the matrix
or vector Z.

Parameters:
N

N is INTEGER
The number of linear equations, i.e., the order of the
matrix A.  N >= 0.

NZ

NZ is INTEGER
We add (NZ+1)*SLAMCH( 'Safe minimum' ) to R(i) in the numerator to
guard against spuriously zero residuals. Default value is N.

NRHS

NRHS is INTEGER
The number of right hand sides, i.e., the number of columns
of the matrices AYB, RES, and BERR.  NRHS >= 0.

RES

RES is REAL array, dimension (N,NRHS)
The residual matrix, i.e., the matrix R in the relative backward
error formula above.

AYB

AYB is REAL array, dimension (N, NRHS)
The denominator in the relative backward error formula above, i.e.,
the matrix abs(op(A_s))*abs(Y) + abs(B_s). The matrices A, Y, and B
are from iterative refinement (see sla_gerfsx_extended.f).

BERR

BERR is REAL array, dimension (NRHS)
The componentwise relative backward error from the formula above.

Author:
Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Date:
September 2012

Definition at line 102 of file sla_lin_berr.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						 sla_lin_berr.f(3)```
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