Re: Solving a large sparse system with a single dense row/column?

Hello,
the package BEMW by Willy Govaerts, to be found on NETLIB, would be a
good candidate.
Simply applying a bandwidth reduction by renumbering the variables
would save you only half the full bandwidth. But you could think of
reformulating your equations, if these derive from a differential
equation: For a single row, which corresponds to a integral, you could
introduce a differential equation I'=f_{n+1}(x), which only increases the
narrow band. Also a column, which corresponds to a parameter in the
system, could by replaced by a trivial DE: p'=0.

Good luck
Alois
.