HP MLIB User's Guide Vol. 2 7th Ed.

Chapter 15 Sparse Eigenvalues and Eigenvectors 1055
Initialize sparse eigenvalues/eigenvectors DSEVIN
msglvl = 3 First stage of debugging output.
msglvl = 4 Complete debugging output.
output Fortran logical unit number to which all printable
output will be written.
Output global Global communications array for this problem. This
array must be passed, untouched by the user, to
successive subroutines in this package.
ier Status response:
ier = 0 Normal return.
ier = −101 Error in dynamic storage allocation.
ier = −102 norder not positive.
Notes Actual character arguments in a subroutine call may be longer than
corresponding dummy arguments. Therefore, readability of the CALL
statement may be improved by coding the bmxtyp argument as ’identity’ or
’diagonal’.
Example Prepare to compute some of the eigenvalues and eigenvectors of a 10,000 by
10,000 matrix (ordinary symmetric for eigenproblem). Obtain error messages
and standard minimal output on Fortran logical unit 6.
INTEGER*4 NORDER, IER
REAL*8 GLOBAL(150)
NORDER = 10000
CALL DSEVIN (NORDER,’IDENTITY’,1,6,GLOBAL,IER)
IF ( IER .NE. 0 ) THEN
handle error condition
ENDIF