# 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 Univ. of Colorado Denver NAG Ltd. Date: September 2012 Definition at line 102 of file sla_lin_berr.f.AuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.2Tue Sep 25 2012 sla_lin_berr.f(3)

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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 Univ. of Colorado Denver NAG Ltd. Date: September 2012 Definition at line 102 of file sla_lin_berr.f.AuthorGenerated automatically by Doxygen for LAPACK from the source code.Version 3.4.2Tue Sep 25 2012 sla_lin_berr.f(3)