def test_stc_arithmetic():
"""Test arithmetic for STC files
"""
fname = op.join(data_path, 'MEG', 'sample', 'sample_audvis-meg')
stc = SourceEstimate(fname)
data = stc.data.copy()
out = list()
for a in [data, stc]:
a = a + a * 3 + 3 * a - a ** 2 / 2
a += a
a -= a
a /= 2 * a
a *= -a
a += 2
a -= 1
a *= -1
a /= 2
a **= 3
out.append(a)
assert_array_equal(out[0], out[1].data)
assert_array_equal(stc.sqrt().data, np.sqrt(stc.data))
