Problem with rectangular matrices

[Matthew Knepley]

I think there is an inconsistency in our definitions. If you create a matrix
which
is 4x8 on 2 procs, then you end up with a row and column map like this:

    rowMap           colMap
  [0..2) [2..4)      [0..4) [4..8)

However, we use the column map for queries which then give nonsense. The
most
damaging is in MatSetValues(). If I give a value for (2,2) on proc 1, then
since
2 < cstart = 4, this value is considered "off-diagonal" and can cause a
malloc(). So
I think we have a choice. We can define "diagonal block" to have this weird
shape,
or we can change all queries for the diagonal block to use only the rowMap.
I vote
for the latter, but does anyone have an objection?

   Matt

-- 
What most experimenters take for granted before they begin their experiments
is infinitely more interesting than any results to which their experiments
lead.
-- Norbert Wiener
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