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yap-6.3/packages/CLPBN/learning/bnt_parms.yap
2009-02-16 12:23:29 +00:00

122 lines
2.8 KiB
Prolog

%
% Learn parameters using the BNT toolkit
%
:- yap_flag(unknown,error).
:- style_check(all).
:- module(bnt_parameters, [learn_parameters/2]).
:- use_module(library('clpbn'), [
clpbn_flag/3]).
:- use_module(library('clpbn/bnt'), [
create_bnt_graph/2]).
:- use_module(library('clpbn/display'), [
clpbn_bind_vals/3]).
:- use_module(library('clpbn/dists'), [
get_dist_domain/2
]).
:- use_module(library(matlab), [matlab_initialized_cells/4,
matlab_call/2,
matlab_get_variable/2
]).
:- dynamic bnt_em_max_iter/1.
bnt_em_max_iter(10).
% syntactic sugar for matlab_call.
:- op(800,yfx,<--).
G <-- Y :-
matlab_call(Y,G).
learn_parameters(Items, Tables) :-
run_all(Items),
clpbn_flag(solver, OldSolver, bnt),
clpbn_flag(bnt_model, Old, tied),
attributes:all_attvars(AVars),
% sort and incorporte evidence
clpbn_vars(AVars, AllVars),
length(AllVars,NVars),
create_bnt_graph(AllVars, Reps),
mk_sample(AllVars,NVars,EvVars),
bnt_learn_parameters(NVars,EvVars),
get_parameters(Reps, Tables),
clpbn_flag(solver, bnt, OldSolver),
clpbn_flag(bnt_model, tied, Old).
run_all([]).
run_all([G|Gs]) :-
call(user:G),
run_all(Gs).
clpbn_vars(Vs,BVars) :-
get_clpbn_vars(Vs,CVs),
keysort(CVs,KVs),
merge_vars(KVs,BVars).
get_clpbn_vars([],[]).
get_clpbn_vars([V|GVars],[K-V|CLPBNGVars]) :-
clpbn:get_atts(V, [key(K)]), !,
get_clpbn_vars(GVars,CLPBNGVars).
get_clpbn_vars([_|GVars],CLPBNGVars) :-
get_clpbn_vars(GVars,CLPBNGVars).
merge_vars([],[]).
merge_vars([K-V|KVs],[V|BVars]) :-
get_var_has_same_key(KVs,K,V,KVs0),
merge_vars(KVs0,BVars).
get_var_has_same_key([K-V|KVs],K,V,KVs0) :- !,
get_var_has_same_key(KVs,K,V,KVs0).
get_var_has_same_key(KVs,_,_,KVs).
mk_sample(AllVars,NVars, LL) :-
add2sample(AllVars, LN),
length(LN,LL),
matlab_initialized_cells( NVars, 1, LN, sample).
add2sample([], []).
add2sample([V|Vs],[val(VId,1,Val)|Vals]) :-
clpbn:get_atts(V, [evidence(Ev),dist(Id,_)]), !,
bnt:get_atts(V,[bnt_id(VId)]),
get_dist_domain(Id, Domain),
evidence_val(Ev,1,Domain,Val),
add2sample(Vs, Vals).
add2sample([_V|Vs],Vals) :-
add2sample(Vs, Vals).
evidence_val(Ev,Val,[Ev|_],Val) :- !.
evidence_val(Ev,I0,[_|Domain],Val) :-
I1 is I0+1,
evidence_val(Ev,I1,Domain,Val).
bnt_learn_parameters(_,_) :-
engine <-- jtree_inf_engine(bnet),
% engine <-- var_elim_inf_engine(bnet),
% engine <-- gibbs_sampling_inf_engine(bnet),
% engine <-- belprop_inf_engine(bnet),
% engine <-- pearl_inf_engine(bnet),
bnt_em_max_iter(MaxIters),
[new_bnet, trace] <-- learn_params_em(engine, sample, MaxIters).
get_parameters([],[]).
get_parameters([Rep-v(_,_,_)|Reps],[CPT|CPTs]) :-
get_new_table(Rep,CPT),
get_parameters(Reps,CPTs).
get_new_table(Rep,CPT) :-
s <-- struct(new_bnet.'CPD'({Rep})),
matlab_get_variable( s.'CPT', CPT).