ZGERFS - Online Linux Manual PageSection : 1
Updated : November 2008
Source : LAPACK routine (version 3.2)
Note : LAPACK routine (version 3.2)

NAMEZGERFS - improves the computed solution to a system of linear equations and provides error bounds and backward error estimates for the solution

SYNOPSISSUBROUTINE ZGERFS(  TRANS, N, NRHS, A, LDA, AF, LDAF, IPIV, B, LDB, X, LDX, FERR, BERR, WORK, RWORK, INFO )  CHARACTER TRANS  INTEGER INFO, LDA, LDAF, LDB, LDX, N, NRHS  INTEGER IPIV( * )  DOUBLE PRECISION BERR( * ), FERR( * ), RWORK( * )  COMPLEX*16 A( LDA, * ), AF( LDAF, * ), B( LDB, * ), WORK( * ), X( LDX, * )

PURPOSEZGERFS improves the computed solution to a system of linear equations and provides error bounds and backward error estimates for the solution.

ARGUMENTSTRANS (input) 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)
N (input) INTEGER  The order of the matrix A. N >= 0. NRHS (input) INTEGER  The number of right hand sides, i.e., the number of columns of the matrices B and X. NRHS >= 0. A (input) COMPLEX*16 array, dimension (LDA,N)  The original N-by-N matrix A. LDA (input) INTEGER  The leading dimension of the array A. LDA >= max(1,N). AF (input) COMPLEX*16 array, dimension (LDAF,N)  The factors L and U from the factorization A = P*L*U as computed by ZGETRF. LDAF (input) INTEGER  The leading dimension of the array AF. LDAF >= max(1,N). IPIV (input) INTEGER array, dimension (N)  The pivot indices from ZGETRF; for 1<=i<=N, row i of the matrix was interchanged with row IPIV(i). B (input) COMPLEX*16 array, dimension (LDB,NRHS)  The right hand side matrix B. LDB (input) INTEGER  The leading dimension of the array B. LDB >= max(1,N). X (input/output) COMPLEX*16 array, dimension (LDX,NRHS)  On entry, the solution matrix X, as computed by ZGETRS. On exit, the improved solution matrix X. LDX (input) INTEGER  The leading dimension of the array X. LDX >= max(1,N). FERR (output) DOUBLE PRECISION array, dimension (NRHS)  The estimated forward error bound for each solution vector X(j) (the j-th column of the solution matrix X). If XTRUE is the true solution corresponding to X(j), FERR(j) is an estimated upper bound for the magnitude of the largest element in (X(j) - XTRUE) divided by the magnitude of the largest element in X(j). The estimate is as reliable as the estimate for RCOND, and is almost always a slight overestimate of the true error. BERR (output) DOUBLE PRECISION array, dimension (NRHS)  The componentwise relative backward error of each solution vector X(j) (i.e., the smallest relative change in any element of A or B that makes X(j) an exact solution). WORK (workspace) COMPLEX*16 array, dimension (2*N)  RWORK (workspace) DOUBLE PRECISION array, dimension (N)  INFO (output) INTEGER  = 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value

PARAMETERSITMAX is the maximum number of steps of iterative refinement.
0
Johanes Gumabo
Data Size   :   12,257 byte
man-zgerfs.lBuild   :   2024-12-05, 20:55   :  
Visitor Screen   :   x
Visitor Counter ( page / site )   :   3 / 170,901
Visitor ID   :     :  
Visitor IP   :   3.145.55.25   :  
Visitor Provider   :   AMAZON-02   :  
Provider Position ( lat x lon )   :   39.962500 x -83.006100   :   x
Provider Accuracy Radius ( km )   :   1000   :  
Provider City   :   Columbus   :  
Provider Province   :   Ohio ,   :   ,
Provider Country   :   United States   :  
Provider Continent   :   North America   :  
Visitor Recorder   :   Version   :  
Visitor Recorder   :   Library   :  
Online Linux Manual Page   :   Version   :   Online Linux Manual Page - Fedora.40 - march=x86-64 - mtune=generic - 24.12.05
Online Linux Manual Page   :   Library   :   lib_c - 24.10.03 - march=x86-64 - mtune=generic - Fedora.40
Online Linux Manual Page   :   Library   :   lib_m - 24.10.03 - march=x86-64 - mtune=generic - Fedora.40
Data Base   :   Version   :   Online Linux Manual Page Database - 24.04.13 - march=x86-64 - mtune=generic - fedora-38
Data Base   :   Library   :   lib_c - 23.02.07 - march=x86-64 - mtune=generic - fedora.36

Very long time ago, I have the best tutor, Wenzel Svojanovsky . If someone knows the email address of Wenzel Svojanovsky , please send an email to johanes_gumabo@yahoo.co.id .
If error, please print screen and send to johanes_gumabo@yahoo.co.id
Under development. Support me via PayPal.