.TH "dla_lin_berr.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*-
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.SH NAME
dla_lin_berr.f \- 
.SH SYNOPSIS
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.SS "Functions/Subroutines"

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.ti -1c
.RI "subroutine \fBdla_lin_berr\fP (N, NZ, NRHS, RES, AYB, BERR)"
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.RI "\fI\fBDLA_LIN_BERR\fP computes a component-wise relative backward error\&. \fP"
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.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine dla_lin_berr (integerN, integerNZ, integerNRHS, double precision, dimension( n, nrhs )RES, double precision, dimension( n, nrhs )AYB, double precision, dimension( nrhs )BERR)"

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\fBDLA_LIN_BERR\fP computes a component-wise relative backward error\&.  
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\fBPurpose: \fP
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.nf
    DLA_LIN_BERR computes component-wise 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 component-wise absolute value of the matrix
    or vector Z.
.fi
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.RE
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\fBParameters:\fP
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\fIN\fP 
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          N is INTEGER
     The number of linear equations, i.e., the order of the
     matrix A.  N >= 0.
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\fINZ\fP 
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          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.
.fi
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\fINRHS\fP 
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          NRHS is INTEGER
     The number of right hand sides, i.e., the number of columns
     of the matrices AYB, RES, and BERR.  NRHS >= 0.
.fi
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\fIRES\fP 
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          RES is DOUBLE PRECISION array, dimension (N,NRHS)
     The residual matrix, i.e., the matrix R in the relative backward
     error formula above.
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\fIAYB\fP 
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          AYB is DOUBLE PRECISION 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 dla_gerfsx_extended.f).
.fi
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\fIBERR\fP 
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          BERR is DOUBLE PRECISION array, dimension (NRHS)
     The component-wise relative backward error from the formula above.
.fi
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\fBAuthor:\fP
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Univ\&. of Tennessee 
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Univ\&. of California Berkeley 
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Univ\&. of Colorado Denver 
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NAG Ltd\&. 
.RE
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\fBDate:\fP
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September 2012 
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Definition at line 102 of file dla_lin_berr\&.f\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.