[purge.c] implemented new way of pruning excess relations (announced in 	  previous commit). In fact I optimize n/N+w/W and not only w/W 	  (see details in source code). Some figures on the c59:
[purge.c] implemented new way of pruning excess relations (announced in
	  previous commit). In fact I optimize n/N+w/W and not only w/W
	  (see details in source code). Some figures on the c59:

./new_run.c59 (no pruning in purge, excess is removed by merge):
    Info: Number of relations left: 529322.            # after duplicates
    Info: Nrows: 91583; Ncols: 81583; Excess: 10000.   # after purge
    Info: Minimal bwcost: 20938683870.
    Info: Nrows: 15054; Ncols: 14813; Weight: 1390945. # after merge

./new_run.c59 keeppurge=1000 (old version of purge):
    Info: Number of relations left: 529322.
    Info: Nrows: 70754; Ncols: 69754; Excess: 1000.
    Info: Minimal bwcost: 28098576084.
    Info: Nrows: 27316; Ncols: 26477; Weight: 1028649.

./new_run.c59 keeppurge=1000 (new version of purge):
    Info: Number of relations left: 529322.
    Info: Nrows: 46760; Ncols: 45760; Excess: 1000.
    Info: Minimal bwcost: 16973031221.
    Info: Nrows: 22171; Ncols: 21331; Weight: 765566.

Thus we get a 19% decrease in bwcost wrt -keep 10000. I have no idea if this
improvement will remain once Markowitz is active...

Anyway I think we now can safely remove the pruning in merge.


git-svn-id: 189946a10c5fc96e9dd03ba7cba917cd4c3d09f4@1768 de4796e2-0b1e-0410-91b4-86bc23549317

mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs