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Several drivers may be used to solve the same problem.
However, one driver may work better or may be easier to modify than
the other depending on the nature of the application. The decision
of what to use should be based on the type of problem to be solved
and the part of the spectrum that is of interest. Typically,
regular mode drivers can be used to find extremal eigenvalues
and shift-invert drivers are used to find interior eigenvalues
or extremal eigenvalues that are clustered.
All of the drivers discussed in the previous sections are available
in band form. For more detail on a particular mode, select the
driver from the appropriate section above and then use its banded
counterpart. For example, if the appropriate general driver is
dndrv4 then the corresponding band driver would be dnbdr4.
The primary difference between these two is that dnbdr4
has been derived from dndrv4 by modifying it to use
band storage and LAPACK band factorization routines.