예제 #1
0
파일: sasearch.py 프로젝트: tomisilander/bn
    def main(bdtfile,
             scoretype='BDeu',
             ess=1.0,
             time=None,
             iters=None,
             outfile=None,
             constraint_file="",
             startbn=None,
             cachefile=None):

        global searchtime

        cstrs = Constraints(constraint_file)

        if startbn != None:
            bn = bnmodule.load(startbn, do_pic=False)
            sc = scorefactory.getscorer(bdtfile,
                                        scoretype,
                                        ess,
                                        cachefile=cachefile)
        else:
            bn, sc = bnsearch.empty_net(bdtfile,
                                        scoretype,
                                        ess,
                                        cachefile=cachefile)

            if constraint_file:  # should check if compatible with start
                for a in cstrs.must:
                    bn.addarc(a)

                    sc.score_new(bn)
                    bn.picall()

        searchtime = sigpool.str2time(time)
        endtime = tim.time() + searchtime
        t0 = find_initial_temperature(bn, sc)

        isss = {
            "searchtime": searchtime,
            "endtime": endtime,
            "t0": t0,
            "t": t0
        }
        isss.update(bnsearch.initial_search_status(bn, sc))

        bnsearch.localsearch(isss, sa_step, sa_stop)

        if outfile:
            isss["best_bn"].save(outfile)

        print isss["best_score"]
예제 #2
0
파일: sasearch.py 프로젝트: tomisilander/bn
def find_initial_temperature(bn, sc):
    def it_accept(n, sss):
        d = n - sss["curr_score"]
        if d < 0:
            sss["dsum"] += d
            sss["k"] += 1
        return True

    it_step = bnsearch.stepper_f(bnsearch.acts, operator.__gt__, it_accept)
    it_stop = bnsearch.stopper_f(5000)
    isss = {"k": 0, "dsum": 0.0}
    isss.update(bnsearch.initial_search_status(bn, sc))
    bnsearch.localsearch(isss, it_step, it_stop)

    return isss["dsum"] / isss["k"] / math.log(0.8)
예제 #3
0
def greedysearch(bn, scr, iters, cstr=None):
    gr_better = operator.__gt__
    gr_accept = lambda n,sss : n>sss["curr_score"]
    gr_step = bnsearch.stepper_f(bnsearch.acts, gr_better, gr_accept, cstr)
    gr_stop = bnsearch.stopper_f(iters)
    gr_isss = bnsearch.initial_search_status(bn,scr)
    return bnsearch.localsearch(gr_isss, gr_step, gr_stop)
예제 #4
0
파일: sasearch.py 프로젝트: tomisilander/bn
if __name__ == '__main__':
    import sys

    def sa_accept(n, sss):
        c = sss["curr_score"]
        wp = math.exp((n - c) / sss["t"])
        apt = n > c or random.uniform(0, 1) < wp
        return apt

    sa_step = bnsearch.stepper_f(bnsearch.acts, operator.__gt__, sa_accept)

    def sa_stop(sss):
        endtime = sss["endtime"]
        currtime = time.time()
        lefttime = endtime - currtime
        sss["t"] = sss["t0"] * lefttime / searchtime  # update temperature
        return currtime >= endtime

    bn, sc = bnsearch.sys2bnscr()
    searchtime = int(sys.argv[4])
    endtime = time.time() + searchtime
    t0 = find_initial_temperature(bn, sc)

    isss = {"searchtime": searchtime, "endtime": endtime, "t0": t0, "t": t0}
    isss.update(bnsearch.initial_search_status(bn, sc))

    bnsearch.localsearch(isss, sa_step, sa_stop)

    print isss["best_score"], isss["best_bn"].arcs()