add target andsteady state iters

sho/iters.py

@@ -1,16 +1,50 @@
 import sys
+from collections import deque
 
 ########################################################################
 # Stopping criterions
 ########################################################################
 
 def max(i, val, sol, nb_it):
+    """Stop after reaching nb_it iterations."""
     if i < nb_it:
         return True
     else:
         return False
 
 
+def target(i, val, sol, target):
+    """Stop after reaching target value."""
+    if val < target:
+        return True
+    else:
+        return False
+
+
+class steady:
+    """Stop if improvement is lesser than epsilon, in the last delta iterations."""
+
+    def __init__(self, delta, epsilon = 0):
+        self.epsilon = epsilon
+        self.delta = delta
+        self.delta_vals = deque()
+
+    def __call__(self, i, val, sol):
+        if i < self.delta: # Always wait the first delta iterations.
+            self.delta_vals.append(val)
+            return True
+
+        else:
+            #FILO stack.
+            self.delta_vals.popleft()
+            self.delta_vals.append(val)
+
+            if val - self.delta_vals[0] <= self.epsilon:
+                return False # Stop here.
+            else:
+                return True
+
+
 # Stopping criterions that are actually just checkpoints.
 
 def several(i, val, sol, agains):

snp.py

@@ -34,9 +34,14 @@ if __name__=="__main__":
     can.add_argument("-m", "--solver", metavar="NAME", choices=solvers, default="num_greedy",
             help="Solver to use, among: "+", ".join(solvers))
 
-    # TODO add the corresponding stopping criterion.
-    can.add_argument("-t", "--target", metavar="VAL", default=1e-3, type=float,
-            help="Function value target delta")
+    can.add_argument("-t", "--target", metavar="VAL", default=30*30, type=float,
+            help="Objective function value target")
+
+    can.add_argument("-y", "--steady-delta", metavar="NB", default=50, type=float,
+            help="Stop if no improvement after NB iterations")
+    can.add_argument("-e", "--steady-epsilon", metavar="DVAL", default=0, type=float,
+            help="Stop if the improvement of the objective function value is lesser than DVAL")
+
 
     the = can.parse_args()
 
@@ -67,7 +72,10 @@ if __name__=="__main__":
                     make.iter(iters.log,
                         fmt="\r{it} {val}"),
                     make.iter(iters.history,
-                        history = history)
+                        history = history),
+                    make.iter(iters.target,
+                        target = the.target),
+                    iters.steady(the.steady_delta, the.steady_epsilon)
                 ]
             )