= ANUGA Checkpoints =

Since ANUGA may take a long time to run a simulation, it can be prudent to save off the partial results at different stages of execution in case of hardware failure or power loss.

== cPickle Method ==

Many people have requested restore point functionality in ANUGA to deal with interruptions to a running script. Python already has the ability to save state to a file using the cPickle module.

You can use code like this in your application to implement restore points:

{{{
import cPickle

start_time = 0.0
if use_restore_point is True:
    print 'resuming from restore point...'
    domain = cPickle.load(open('domain_pickle.txt'))
    start_time = domain.time
else:
    # do your normal domain initialisation here


for restorepoint in range(start_time, 10):
    # evolve domain in small chunks, regularly pickling a restore point
    for t in domain.evolve(yieldstep=0.1, finaltime=restorepoint):
        pass
    print 'saving restore point...'
    cPickle.dump(domain, open('domain_pickle.txt', 'w'))
}}}

== use_cache Method ==
ANUGA also has inbuilt caching functionality. You can set the use_cache = True parameter on many functions, and the results of the operation will be stored on disk for the next time the same operation is executed.