Module F04QAF in NAG

• NAG Information

• Components
  • Documentation from ITL
  • Example from ITL
  • Example-output from ITL

F04QAF

 
Solves sparse unsymmetric equations, sparse linear least squares problems and
sparse damped linear least squares problems using a Lanczos algorithm.
 
Classes  :  D2a4 . Solution of systems of linear equations, including matrix
                 inverses, and LU and related factorizations (real
                 nonsymmetric sparse matrices)
            D9a1 . Least squares (L-2) solution of singular, overdetermined or
                 underdetermined systems of linear equations without
                 constraints
 
Type     : Fortran subroutine in NAG library (F04 sublibrary).
Access   : Proprietary. Many implementations available.
Precision: Double.
 
Usage    : CALL F04QAF (M,N,B,X,SE,APROD,DAMP,ATOL,BTOL, CONLIM,ITNLIM,MSGLVL,ITN,
           ANORM,ACOND,RNORM,ARNORM, XNORM,WORK,RWORK,LRWORK,IWORK,LIWORK,
           INFORM,IFAIL)
 
Details  : Documentation Example Example-output
Sites    : (1) AIX (2) ITL
 

Implementation of F04QAF from NAG on AIX

 
AIX:       IBM RS6000, National Institute of Standards and Technology (NIST),
           Gaithersburg, MD. Available to NIST staff.
 
Precision: Double.
 
Access available only to NIST staff on internal Unix systems. They may access this
package provided the /itl tree is cross-mounted.
 
   Link         : f77 -o prog prog.f -L/itl/links/generic/lib -lnag
   Documentation: acroread
                  /itl/apps/naglib-19/docs/NAGdoc/fl/pdf/F04/f04qaf_fl19.pdf
   Example      : cat
                  /itl/apps/naglib-19/flib619da/examples/source/f04qafe.f
   Example-outpu: cat
                  /itl/apps/naglib-19/flib619da/examples/results/f04qafe.r
 

Implementation of F04QAF from NAG on ITL

 
ITL:       Unix Workstation Network, National Institute of Standards and
           Technology (NIST), Gaithersburg, MD. Available to NIST staff.
 
Precision: Double.
 
Access available only to NIST staff on internal Unix systems. They may access this
package provided the /itl tree is cross-mounted.
 
   Link         : f77 -o prog prog.f {-lcomplib.sgimath}
                  -L/itl/links/generic/{lib lib32 lib64}{/mips3 /mips4}
                  -lnag
   Documentation: acroread
                  /itl/apps/naglib-19/flib619da/NAGdoc/fl/pdf/F04/f04qaf_fl19.pdf
   Example      : cat
                  /itl/apps/naglib-19/flib619da/examples/source/f04qafe.f
   Example-outpu: cat
                  /itl/apps/naglib-19/flib619da/examples/results/f04qafe.r