Adds some docs and a tool to create the dot files for splitting trees and ad. dist. seqs.

docs/test_selection.tex

@@ -0,0 +1,72 @@
+# Test selection strategies
+
+<intro stays more or less the same>
+
+
+## Augmented DS-method
+
+In order to perform less tests Chow and Vasilevski [...] pioneered the so called
+W-method. In their framework a test query consists of a prefix $p$ bringing the
+SUL to a specific state, a (random) middle part $m$ and a suffix $s$ asserting
+that the SUL is in the appropriate state. This results in a test suite of the
+form $P I^{\leq k} W$, where $P$ is a set of (shortest) access sequences,
+$I^{\leq k}$ the set of all sequences of length at most $k$ and $W$ is the
+characterization set. Classically, this characterization set is constructed by
+taking the set of all (pairwise) separating sequences. For $k=1$ this test suite
+is complete in the sense that if the SUL passes all tests, then either the SUL
+is equivalent to the specification or the SUL has strictly more states than the
+specification. By increasing $k$ we can check additional states.
+
+The generated test suite, however, was still too big in our learning context.
+Fujiwara observed that it is possible to let the set $W$ depend on the state the
+SUL is supposed to be [...]. This allows us to only take a subset of $W$ which
+is relevant for a specific state. This slightly reduces the test suite which is
+as powerful as the full test suite. This methods is known as the Wp-method. More
+importantly, this observation allows for generalizations where we can carefully
+pick the suffixes.
+
+In the presence of an (adaptive) distinguishing sequence we can take $W$ to be a
+single suffix, greatly reducing the test suite. Lee and Yannakakis describe an
+algorithm in [...] (which we will refer to as the LY algorithm) to efficiently
+construct this sequence, if it exists. In our case, most hypotheses did not
+enjoy an adaptive distinguishing sequence. In these cases the incomplete result
+from the LY algorithm still contained a lot of information which we augmented by
+pairwise separating sequences.
+
+As an example we show an incomplete adaptive distinguishing sequence for one of
+the hypothesis in Figure ??. When we apply the input sequence <add concrete
+example> and observe the right output, we know for sure that the SUL was in
+state <state>. Unfortunately not all path lead to a singleton set. When we for
+instance apply the sequence <add concrete example> and observe the right output,
+we know for sure that the SUL was in one of the states <state1, ..., staten>. In
+these cases we can resort the the pairwise separating sequences.
+
+We note that this augmented DS-method is in the worst case not any better than
+the classical Wp-method. In our case, however, it greatly reduced the test
+suites.
+
+Once we have our set of suffixes, which we call $Z$ now, our test algorithm
+works as follows. The algorithm first exhaust the set $P I^{\leq k} Z$. If this
+does not provide a counterexample, we will randomly pick test queries from $P
+I^2 I^\ast Z$, where the algorithm samples uniformly from $P$, $I^2$ and $Z$ (if
+$Z$ contains more that $1$ sequence for the supposed state) and with a geometric
+distribution on $I^\ast$.
+
+
+## Subalphabet selection
+
+During our attempts to learn the ESM we observed that the above method failed to
+produce a certain counterexample. With domain knowledge we were able to provide
+a handcrafted counterexample which allowed the algorithm to completely learn the
+controller. In order to do this automatically we defined a subalphabet which is
+important at the initialization phase of the controller. This subalphabet will
+be used a bit more often that the full alphabet. We do this as follows.
+
+We start testing with the alphabet which provided a counterexample for the
+previous hypothesis (for the first hypothesis we take the subalphabet). If no
+counterexample can be found within a specified query bound, then we repeat with
+the next alphabet. If both alphabets do not produce a counterexample within the
+bound, the bound is increased by some factor and we repeat all.
+
+This method only marginally increases the number of tests. But it did find the
+right counterexample we first had to construct by hand.

lib/write_tree_to_dot.cpp

@@ -1,49 +1,64 @@
-#include "write_tree_to_dot.hpp"
 #include "adaptive_distinguishing_sequence.hpp"
+#include "read_mealy_from_dot.hpp"
 #include "splitting_tree.hpp"
+#include "write_tree_to_dot.hpp"
 
 #include <fstream>
+#include <iostream>
 
 using namespace std;
 
-template <typename T>
+template <typename T, typename Fun>
-ostream & operator<<(ostream& out, vector<T> const & x){
+void print_vec(ostream & out, const vector<T> & x, const string & d, Fun && f) {
-	if(x.empty()) return out;
+	if (x.empty()) return;
 
 	auto it = begin(x);
-	out << *it++;
+	out << f(*it++);
-	while(it != end(x)) out << " " << *it++;
+	while (it != end(x)) out << d << f(*it++);
-	return out;
 }
 
+static const auto id = [](auto x) { return x; };
 
-void write_splitting_tree_to_dot(const splitting_tree& root, ostream& out_){
+
-	write_tree_to_dot(root, [](const splitting_tree & node, ostream& out){
+void write_splitting_tree_to_dot(const splitting_tree & root, ostream & out_) {
-		out << node.states;
+	write_tree_to_dot(root, [](const splitting_tree & node, ostream & out) {
-		if(!node.seperator.empty()){
+		print_vec(out, node.states, " ", id);
-			out << "\\n" << node.seperator;
+		if (!node.seperator.empty()) {
+			out << "\\n";
+			print_vec(out, node.seperator, " ", id);
 		}
 	}, out_);
 }
 
-void write_splitting_tree_to_dot(const splitting_tree& root, const string& filename){
+void write_splitting_tree_to_dot(const splitting_tree & root, const string & filename) {
 	ofstream file(filename);
 	write_splitting_tree_to_dot(root, file);
 }
 
-void write_adaptive_distinguishing_sequence_to_dot(const adaptive_distinguishing_sequence & root, ostream & out_){
+
-	write_tree_to_dot(root, [](const adaptive_distinguishing_sequence & node, ostream& out){
+void write_adaptive_distinguishing_sequence_to_dot(const adaptive_distinguishing_sequence & root, const translation & t, ostream & out_) {
-		if(!node.word.empty()){
+	const auto symbols = create_reverse_map(t.input_indices);
-			out << node.word;
+	size_t overflows = 0;
+	write_tree_to_dot(root, [&symbols, &overflows](const adaptive_distinguishing_sequence & node, ostream & out) {
+		if (!node.word.empty()) {
+			print_vec(out, node.word, " ", [&symbols](auto x){ return "I" + symbols[x]; });
 		} else {
 			vector<state> I(node.CI.size());
-			transform(begin(node.CI), end(node.CI), begin(I), [](const pair<state, state> p){ return p.second; });
+			transform(begin(node.CI), end(node.CI), begin(I), [](auto p){ return p.second; });
-			out << "I = " << I;
+			if (I.size() < 7) {
+				out << '{';
+				print_vec(out, I, ", ", id);
+				out << '}';
+			} else {
+				overflows++;
+				out << I.size() << " states\\n{" << I[0] << ", ...}";
+			}
 		}
 	}, out_);
+	clog << overflows << " overflows" << endl;
 }
 
-void write_adaptive_distinguishing_sequence_to_dot(const adaptive_distinguishing_sequence & root, string const & filename){
+void write_adaptive_distinguishing_sequence_to_dot(const adaptive_distinguishing_sequence & root, const translation & t, const string & filename) {
 	ofstream file(filename);
-	write_adaptive_distinguishing_sequence_to_dot(root, file);
+	write_adaptive_distinguishing_sequence_to_dot(root, t, file);
 }

lib/write_tree_to_dot.hpp

@@ -7,15 +7,15 @@
 
 // Generic printer for tree
 template <typename T, typename NodeString>
-void write_tree_to_dot(const T & tree, NodeString && node_string, std::ostream & out){
+void write_tree_to_dot(const T & tree, NodeString && node_string, std::ostream & out) {
 	using namespace std;
-	out << "digraph g {\n";
+	out << "digraph {\n";
 
 	// breadth first
 	int global_id = 0;
 	queue<pair<int, reference_wrapper<const T>>> work;
 	work.push({global_id++, tree});
-	while(!work.empty()){
+	while (!work.empty()) {
 		const auto id = work.front().first;
 		const T & node = work.front().second;
 		work.pop();
@@ -24,9 +24,10 @@ void write_tree_to_dot(const T & tree, NodeString && node_string, std::ostream &
 		node_string(node, out);
 		out << "\"];\n";
 
-		for(auto && c : node.children){
+		for (auto && c : node.children) {
 			int new_id = global_id++;
-			out << "\ts" << id << " -> " << "s" << new_id << ";\n";
+			out << "\ts" << id << " -> "
+			    << "s" << new_id << ";\n";
 			work.push({new_id, c});
 		}
 	}
@@ -38,8 +39,9 @@ void write_tree_to_dot(const T & tree, NodeString && node_string, std::ostream &
 // Specialized printing for splitting trees and dist seqs
 struct splitting_tree;
 void write_splitting_tree_to_dot(const splitting_tree & root, std::ostream & out);
-void write_splitting_tree_to_dot(const splitting_tree & root, std::string const & filename);
+void write_splitting_tree_to_dot(const splitting_tree & root, const std::string & filename);
 
 struct adaptive_distinguishing_sequence;
-void write_adaptive_distinguishing_sequence_to_dot(const adaptive_distinguishing_sequence & root, std::ostream & out);
+struct translation;
-void write_adaptive_distinguishing_sequence_to_dot(const adaptive_distinguishing_sequence & root, std::string const & filename);
+void write_adaptive_distinguishing_sequence_to_dot(const adaptive_distinguishing_sequence & root, const translation & t, std::ostream & out);
+void write_adaptive_distinguishing_sequence_to_dot(const adaptive_distinguishing_sequence & root, const translation & t, const std::string & filename);

src/trees.cpp

@@ -0,0 +1,28 @@
+#include <adaptive_distinguishing_sequence.hpp>
+#include <read_mealy_from_dot.hpp>
+#include <splitting_tree.hpp>
+#include <write_tree_to_dot.hpp>
+
+#include <string>
+#include <iostream>
+
+using namespace std;
+
+int main(int argc, char * argv[]) {
+	if (argc != 3) return 1;
+	const string filename = argv[1];
+
+	const string randomized_str = argv[2];
+	const bool randomized = randomized_str == "randomized";
+
+	const auto machine_and_translation = read_mealy_from_dot(filename);
+	const auto & machine = machine_and_translation.first;
+	const auto & translation = machine_and_translation.second;
+
+	const auto options = randomized ? randomized_lee_yannakakis_style : lee_yannakakis_style;
+	const auto tree = create_splitting_tree(machine, options);
+	const auto sequence = create_adaptive_distinguishing_sequence(tree);
+
+	write_splitting_tree_to_dot(tree.root, filename + ".tree");
+	write_adaptive_distinguishing_sequence_to_dot(sequence, translation, filename + ".seq");
+}