Discussion related to cado-nfs

["Gross, Samuel" <Samuel.Gross@noblis.org>]

Hello,
I have been doing some heuristics for different configurations in bwc. I 
haven’t found an efficient way of forgetting a previous run of bwc and 
starting over. I have tried 2 things. It seems that discarding all bwc files 
(leaving an empty $name.bwc directory), and all merge files, dep files, 
character, and sqrt files, and use the allow_wipeout=True parameter, I am 
able to start again, but I must repeat merging. Deleting any other 
combination of files, attempting to preserve the merged matrix, results in 
file not found errors.
I have also tried just starting a new working directory, and importing my 
relations. I have not been able to import the filtering results. Moreover, as 
the ./scripts/cadofactor/README indicates:
       “When importing relations, some statistics are gathered by parsing the
       relation files. This is a costly operation, especially when relations
       from a large number of files are gathered. An expedient for this 
problem
       is to create, for each file cxx.sieving.xxx-yyy.zzzzzzz.gz, a file
       cxx.sieving.xxx-yyy.zzzzzzz.gz.stats.txt, which contain the relevant
       statistics. The format of this file should match the format of the
       statistics files produced by the cado-nfs siever with the -stats-stderr
       option. Examples of such statistics files are found as the files
       *.stderr0…”
I have not figured out how to import these stats files as well, and thus 
avoid regenerating them. I have attempted including them in the list @files 
to import, using a separate list, as well as copying to the new work 
directory under $name.upload. Both of these options fail as well for re-using 
the data from the filtering stage. I am hoping that someone can 
1. Clarify the instructions in the README on importing relations and the 
costly operation of re-gathering stats.
2. Suggest a method for restarting after merging and before linear algebra 
begins, ignoring any previous runs.
--sam