ARPACK subroutines

Table 5.1 lists all the auxiliary subroutines of ARPACK.    The naming convention is XY<mnemonic>   The first letter X is one of the letter s,d,c,z and denotes the data type   as follows:

 

s single precision real arithmetic,

d double precision real arithmetic,

c single precision complex arithmetic,

z double precision complex arithmetic.

If the second letter Y occurs, it is one of the letters s, n that denote the type of eigensystem as follows:

n non-symmetric,

s symmetric.

For the subroutines listed in Table 5.1 that start with ``[X1,X2]'', only those data types are available.

 

1|cROUTINE 1c|DESCRIPTION

XYaupd  Top level subroutine that implements the IRAM.

XYeupd  This routine computes eigenvectors and/or Schur vectors for the computed eigenvalues.

XYaup2  Intermediate level interface called by XYaupd that performs the iteration.

Xgetv0  Initial vector generation subroutine.

XYaitr  Arnoldi factorization subroutine.

Xneigh  Compute Ritz values and error bounds subroutine for the non-symmetric and non-Hermitian eigenvalue problems.

[s,d]seigt  Compute Ritz values and error bounds subroutine for the symmetric eigenvalue problem.

XYgets  Sort the Ritz values and corresponding error bounds.

[s,d]Yconv  Determines which Ritz values satisfy the convergence criterion.

XYapps  Application of implicit shifts routine.

  Xortc  Sorting routines for complex vectors.

[s,d]ortr  Sorting routine for real vectors.

[s,d]laqrb  Compute the eigenvalues and the last components of the Schur vectors of an upper Hessenberg matrix.

[s,d]stqrb  Compute the eigenvalues and the last components of the eigenvectors of a symmetric tridiagonal matrix.