[algorithm] fixed bug in the log-prob computation of SKLGMM: 2D array is expected

bob/pad/base/algorithm/SKLGMM.py

@@ -45,7 +45,7 @@ class SKLGMM(Algorithm):
     # The data - "positive class only"
     pos = numpy.array(training_features[0])
     features_dim = pos.shape[1]
-   
+  
     # train
     self.machine.fit(pos)
 
@@ -68,7 +68,8 @@ class SKLGMM(Algorithm):
     """
     Compute the log-likelihood of the feature 
     """
-    # load
+    # sklearn.mixture.GaussianMixture expects a 2d array (even with one example)
+    feature = numpy.expand_dims(feature, axis=0)
     return self.machine.score_samples(feature)
 
   def score(self, toscore):