added basic sampling functionality

Author: zwergziege

aalpy/utils/Sampling.py

@@ -0,0 +1,40 @@
+from random import randint, choices, random
+
+from aalpy import MooreMachine, Dfa, NDMooreMachine, Mdp, MarkovChain
+from aalpy.base import Automaton, DeterministicAutomaton
+
+
+def sample_with_length_limits(alphabet, nr_samples, min_len, max_len):
+    return [choices(alphabet, k = randint(min_len, max_len)) for _ in range(nr_samples)]
+
+
+def sample_with_term_prob(alphabet, nr_samples, term_prob):
+    ret = []
+    for _ in range(nr_samples):
+        k = 0
+        while term_prob < random():
+            k += 1
+        ret.append(choices(alphabet, k=k))
+    return ret
+
+
+def get_complete_sample(automaton: DeterministicAutomaton):
+    alphabet = automaton.get_input_alphabet()
+    automaton.compute_prefixes()
+    char_set = automaton.compute_characterization_set()
+    infixes = [(x,) for x in alphabet] + [tuple()]
+    return [state.prefix + infix + suffix for state in automaton.states for suffix in char_set for infix in infixes]
+
+
+def get_io_traces(automaton: Automaton, input_traces: list) -> list:
+    moore_automata = (MooreMachine, NDMooreMachine, Mdp, MarkovChain)
+    is_moore = isinstance(automaton, moore_automata)
+
+    traces = []
+    for input_trace in input_traces:
+        output_trace = automaton.execute_sequence(automaton.initial_state, input_trace)
+        trace = list(zip(input_trace, output_trace))
+        if is_moore:
+            trace = [automaton.initial_state.output] + trace
+        traces.append(trace)
+    return traces