Module F08HCF in NAG

• NAG Information

• Components
  • Documentation from AIX
  • Example from AIX
  • Example-input from AIX
  • Example-output from AIX

F08HCF

 
Computes all the eigenvalues, and optionally all the eigenvectors, of a real
ymmetric band matrix. If the eigenvectors are requested, then it uses a divide and
conquer algorithm to compute eigenvalues and eigenvectors. However, if only
eigenvalues are required, then it uses the Pal-Walker-Kahan variant of the QL or
QR algorithm. (DSBEVD).
 
Classes  :  D4a1 . Real symmetric matrix eigenvalue problems
            D4a6 . Banded matrix eigenvalue problems
 
Type     : Fortran subroutine in NAG library (F08 sublibrary).
Access   : Proprietary. Many implementations available.
Precision: Double.
 
Usage    : CALL F08HCF(JOB, UPLO, N, KD, AB, LDAB, W, Z, LDZ, WORK, LWORK, IWORK,
           LIWORK, INFO)
 
Details  : Documentation Example Example-input Example-output
Sites    : (1) AIX
 

Implementation of F08HCF 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/F08/f08hcf_fl19.pdf
   Example      : cat
                  /itl/apps/naglib-19/flib619da/examples/source/f08hcfe.f
   Example-input: cat
                  /itl/apps/naglib-19/flib619da/examples/data/f08hcfe.d
   Example-outpu: cat
                  /itl/apps/naglib-19/flib619da/examples/results/f08hcfe.r