3 X Area will not equal the value of lumped summed mass if I
set rho = 1.0 because the terms in lumped sum( although based on the [B] matrix
which results from interpolating Ux, Uy, Uz) have rotation terms which when lumped
with the translation in z, do not produce 3 X Area.  What I can do is print just
the value of Area, and comment out the first 2 rows of the [B] matrix, which will
result in only summing over translation z.  Also remember to change the thickness
to 1.0.




First analysis
--------------

The file p1 does not work for eigenvalue analysis when you do conjugate gradient.
The reason is that it is not converging due to what I suspect is the behavior
of the r vector, which acts like the force vector.  Everything seems to be working
correctly since a standard linear analysis works fine with the force vector.  But
something about the r vector that's getting passed isn't working.  But for the
much more complex mesh quad, it does work.  Just stick with the parameters 
given in plinput for p1, but know that it won't converge.


Second analysis
--------------

It turns out that the problem is really due to the accumulation of some type of
numerical error.  But there's more to it than that.  If I calculate 3 eigenvalues
or less, there is convergence between the linear method as well as the conjugate
gradient method.  Anymore, and the numerical error accumulates to a great extent
from CG resulting in a great disparity in results.  One thing to note is that
while the 3 eigenvalues match the first 3 from the problem for when 5 are calculated
using linear analysis, only the first eigenmode matches.   This is hard to
explain.  In fact if you calculate 1 eigenmode, the 1 eigenvalue still almost
matches, but the eigenmode is different with the first eigenmode from the 5 eigenmode
calculation.  If you calculate 2, the first mode will again match,
but the second won't.  The 2 eigenvalues will match though.


