def test_pick_channels_mixin():
"""Test channel-picking functionality
"""
# preload is True
raw = Raw(fif_fname, preload=True)
ch_names = raw.ch_names[:3]
ch_names_orig = raw.ch_names
dummy = raw.pick_channels(ch_names, copy=True) # copy is True
assert_equal(ch_names, dummy.ch_names)
assert_equal(ch_names_orig, raw.ch_names)
assert_equal(len(ch_names_orig), raw._data.shape[0])
raw.pick_channels(ch_names, copy=False) # copy is False
assert_equal(ch_names, raw.ch_names)
assert_equal(len(ch_names), len(raw.cals))
assert_equal(len(ch_names), raw._data.shape[0])
# preload is False
raw = Raw(fif_fname, preload=False)
ch_names = raw.ch_names[:3]
ch_names_orig = raw.ch_names
dummy = raw.pick_channels(ch_names, copy=True) # copy is True
assert_equal(ch_names, dummy.ch_names)
assert_equal(ch_names_orig, raw.ch_names)
raw.pick_channels(ch_names, copy=False) # copy is False
assert_equal(ch_names, raw.ch_names)
assert_equal(len(ch_names), len(raw.cals))
