search

vcphub / cspsol

Try column generation techniques on cutting stock problem
GNU General Public License v3.0
0 stars 0 forks source link

Run time control #8

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago 
Consider the data set

5900
2949 130
2860 101
2849 101
1710 10
1680 11
1305 11
1230 42
1080 1
480 4
380 30
330 8

Command:

./cspsol --cgroot --data /cspsol-data.txt

On a modern OS X machine this takes approx 500 secs to exhaust the tree (even 
with --cgroot).
Extending the stock length to 5950 gives a solution within just 7 secs or so.

I am using cspsol to drive a web based interactive solution.
In order to deal with the variability in timing I have modified cspsol as 
follows:

1. Added a --maxtime N option that ends the node search after N seconds. This 
does not exhaust the tree but merely returns the current optimal solution. 
This works well in an interactive environment as the user can choose to balance 
time against optimality.

2. Also added a --vsilent option that redirects stdout to /dev/null. cout.txt 
can easily run to hundreds of megabytes when using --silent.

If you think these changes suitable for the repo I will post the diffs.

Original issue reported on code.google.com by jonathan...@yahoo.com on 25 Nov 2009 at 10:50

GoogleCodeExporter commented 9 years ago 
Yes please go ahead and share the code changes.

Original comment by vijay.pa...@gmail.com on 28 Nov 2009 at 5:40

GoogleCodeExporter commented 9 years ago 
Requested features will likely be available in next release cspsol-1.1.

Original comment by vijay.pa...@gmail.com on 20 Jan 2010 at 5:24

GoogleCodeExporter commented 9 years ago 
See : 
http://code.google.com/p/cspsol/source/detail?r=55

Silent mode and log file feature.
1. Silent mode (--silent) shuns any output to 'cout'. Neither to terminal 
nor to a file. Errors to 'cerr' should be printed.
2. Terminal output could be re-directed to user specified file using command
line option '--log filename'. Similar to glpsol, however not a copy of terminal 
output
but redirection.
3. BB progress report and debug info is always produced in file 
'bb_progress.txt'.
In future, a way could be provided to turn this OFF.

Original comment by vijay.pa...@gmail.com on 22 Jan 2010 at 5:01

GoogleCodeExporter commented 9 years ago 
Thanks for providing this functionality.

Works well.

Sorry that I forgot to post my own implementation of this feature.
I have retained your version.

Jonathan Mitchell

Original comment by muggins...@googlemail.com on 23 Apr 2010 at 9:34