precomputed kernel format

eccv12/lfw.py

@@ -526,10 +526,22 @@ def train_view2(namebases, basedirs, test=None, use_libsvm=False):
 
         print ('Training split %d ...' % ind)
         if use_libsvm:
-            svm, _ = train_scikits(train_Xyd_n,
+            if hasattr(use_libsvm, 'keys'):
+                kernel_choice = use_libsvm.get('kernel_choice', 'linear')
+            else:
+                kernel_choice = 'linear'
+            if kernel_choice == 'precomputed':
+                (_X, _y, _d) = train_Xyd_n
+                print ('Computing kernel ...')
+                K = np.dot(_X, _X.T)
+                print ('... computed kernel of shape', K.shape)
+                train_data = (K, _y, _d)
+            else:
+                train_data = train_Xyd_n
+            svm, _ = train_scikits(train_data,
                                 labelset=[-1, 1],
                                 model_type='svm.SVC',
-                                model_kwargs={'kernel': 'linear'},
+                                model_kwargs={'kernel': kernel_choice},
                                 normalization=False
                                 )
         else:

eccv12/tests/test_lfw.py

@@ -268,3 +268,13 @@ def test_baby_view2_libsvm():
                            test=test_set)
     return lfw.train_view2(['libsvm'],[os.getcwd()],
                            test=test_set, use_libsvm=True)
+
+
+@attr('slow') #takes about 30 sec with cpu
+def test_baby_view2_libsvm_kernel():
+    c = config_tiny_rnd0
+    test_set = range(20) + range(500, 520)
+    lfw.get_view2_features(c['slm'], c['preproc'], 'mult', 'libsvm', os.getcwd(),
+                           test=test_set)
+    return lfw.train_view2(['libsvm'],[os.getcwd()],
+                           test=test_set, use_libsvm={'kernel_choice': 'precomputed'})