feature #188; get_fixed_model() - do nothing if 0 params

anticipy/forecast_models.py

@@ -1192,6 +1192,8 @@ def _f_init_bounds_fourier_yearly(a_x=None, a_y=None, a_date=None):
 
 def get_fixed_model(forecast_model, params_fixed, is_mult=False):
     # Generate model with some fixed parameters
+    if forecast_model.n_params == 0:  # Nothing to do
+        return forecast_model
     if len(params_fixed) != forecast_model.n_params:
         err = 'Wrong number of fixed parameters'
         raise ValueError(err)

tests/test_forecast_model.py

@@ -799,7 +799,8 @@ def test_get_model_outliers_withgap(self):
         # - get list of steps
         # - if a step is in a filled gap, move to next sample
 
-    def test_fixed_model_creation(self):
+    def test_get_fixed_model(self):
+        logger.info('Test 1 - default settings')
         a_x = np.arange(0, 10)
         a_date = pd.date_range('2014-01-01', periods=10, freq='D')
 
@@ -809,6 +810,10 @@ def test_fixed_model_creation(self):
         a2 = model_constant_fixed(a_x, a_date, None)
         self.assert_array_equal(a1, a2)
 
+        logger.info('Test 2 - 0-param model')
+        model_out = get_fixed_model(model_naive, [])
+        self.assertEqual(model_out.name, 'naive')
+
     def test_fix_params_fmodel(self):
         a_x = np.arange(0, 10)
         a_date = pd.date_range('2014-01-01', periods=10, freq='D')