The cmiss backend (cm) uses a memory management model where it allocates all the memory it is going to need at once based on the node and element id numbers (is that right? yep - node and element numbers are simply indices into the various arrays rather than actual identitifiers).

This means that if you have a mesh with only 2 nodes numbered 10001,10002 then cm will allocate enough memory for 10002 nodes even though your problem has only 2 nodes. Therefore to minimise the memory required by the backend it is necessary to renumber nodes and elements so that the id numbers are in a contiguous block starting at 1.

This can be done with the front end command [gfx change_identifier].

From jdoe Wed Jun 2 14:29:32 +1200 2004
From: jdoe
Date: Wed, 02 Jun 2004 14:29:32 +1200
Subject: very cool 
Message-ID: <20040602142932+1200@bioeng3:9080>

never heard of this before!