Added two exceptions for issues frequently met.

Author: Tanguy Damart

bluepyopt/deapext/optimisations.py

@@ -160,6 +160,12 @@ def setup_deap(self):
 
         # Number of parameters
         IND_SIZE = len(self.evaluator.params)
+        
+        if IND_SIZE == 0:
+            raise Exception(
+                "Length of evaluator.params is zero. At least one "
+                "non-fix parameter is neededto run an optimization."
+            )
 
         # Bounds for the parameters
         LOWER = []

bluepyopt/deapext/optimisationsCMA.py

@@ -91,9 +91,12 @@ def __init__(
         self.hof = hof
         if self.hof is None:
             self.hof = deap.tools.HallOfFame(10)
-
-        self.fitness_reduce = fitness_reduce
+        
+        if offspring_size < 2:
+            raise Exception("offspring_size has to be at least 2.")
         self.offspring_size = offspring_size
+        
+        self.fitness_reduce = fitness_reduce
         self.centroids = centroids
         self.sigma = sigma
 
@@ -293,8 +296,10 @@ def run(
                 lbounds=self.lbounds, ubounds=self.ubounds
             )
             logger.debug(
-                "Number of individuals outside of bounds: {} ({:.2f}%)" +
-                "".format(n_out, 100.0 * n_out / len(CMA_es.population))
+                "Number of individuals outside of bounds: {} ({:.2f}%)".format(
+                    n_out,
+                    100.0 * n_out / len(CMA_es.population)
+                )
             )
 
             # Get all the individuals in the original space for evaluation

bluepyopt/tests/test_deapext/test_optimisationsCMA.py

@@ -33,5 +33,3 @@ def test_optimisationsCMA_run():
     optimiser = bluepyopt.deapext.optimisationsCMA.DEAPOptimisationCMA
     optimisation = optimiser(evaluator=evaluator, centroids=[x])
     pop, hof, log, hist = optimisation.run(max_ngen=2)
-    raised = False
-    nt.assert_equal(raised, False)