Cannot access raw-matrix for mixed function spaces

[Florian Bruckner]

Hello,

if i try to access A.array() after the assembly within the demo_stokes-iterative.py example, a memory error is raised:

---------------------------------------------------------------------------
MemoryError                               Traceback (most recent call last)
<ipython-input-5-dc6137c9900a> in <module>()
----> 1 A.array()

/usr/lib/python2.7/dist-packages/dolfin/cpp/la.pyc in array(self)
    571         from numpy import zeros
    572         m_range = self.local_range(0);
--> 573         A = zeros((m_range[1] - m_range[0], self.size(1)))
    574         for i, row in enumerate(range(*m_range)):
    575             column, values = self.getrow(row)

MemoryError: 

doing the same within demo_poisson.py gives a correct output, so i could be a problem with the mixed function space.

greeting FloB

[Jan Blechta]

I have a suspicion that you get really run out of memory when asking for A.array() which is dense.

[Chris Richardson]

A.array() is too big to fit in memory. If you change the problem size to UnitCubeMesh(2, 2, 2) for example, it will work.