PCA
Traceback (most recent call last):
  File "c:\orange\Orange/testing/regression\xtest_one.py", line 115, in <module>
    execfile(t__name)
  File "freeviz-pca.py", line 26, in <module>
    freeviz.find_projection(Orange.projection.linear.DR_PCA, set_anchors=True)
  File "c:\orange\Orange\utils\__init__.py", line 201, in wrap_call
    return func(*args, **kwargs)
  File "c:\orange\Orange\utils\__init__.py", line 201, in wrap_call
    return func(*args, **kwargs)
  File "c:\orange\Orange\projection\linear.py", line 938, in find_projection
    pca = pca(data.Table(domain, data_matrix.T))
  File "c:\orange\Orange\projection\linear.py", line 1338, in __call__
    Xd, stdev, mean, relevant_features = self._normalize_data(dataset)
  File "c:\orange\Orange\projection\linear.py", line 1373, in _normalize_data
    raise ValueError("All features are constant")
ValueError: All features are constant
