A test for mne-python bdf reader for larger files

test_big_bdf.py

import os.path as op
import inspect

from nose.tools import assert_equal, assert_true
from numpy.testing import assert_array_almost_equal, assert_array_equal
from numpy.testing import assert_raises
from scipy import io
import numpy as np

from mne.externals.six import iterbytes
from mne.utils import _TempDir
from mne.io import Raw
from mne.io import read_raw_edf

FILE = inspect.getfile(inspect.currentframe())
data_dir = op.join(op.dirname(op.abspath(FILE)))
bdf_path = op.join(data_dir, 'AA_136.bdf')


tempdir = _TempDir()


raw1 = read_raw_edf(bdf_path, preload=False)
raw1_file = op.join(tempdir, 'test1-raw.fif')
raw1.save(raw1_file, overwrite=True, buffer_size_sec=25)
raw11 = Raw(raw1_file, preload=True)

chunk = 25000
test_range = raw1.last_samp-chunk
for i in range(10):
    start = np.random.random_integers(0,test_range)
    data1, times1 = raw1[:, start:start+chunk]
    data11, times11 = raw11[:, start:start+chunk]

    assert_array_almost_equal(data1, data11, 8)
    assert_array_almost_equal(times1, times11)
    assert_equal(sorted(raw1.info.keys()), sorted(raw11.info.keys()))

del raw1, raw11

# test the _read_segment function by only loading some of the data
raw2 = read_raw_edf(bdf_path, preload=False)
raw22 = read_raw_edf(bdf_path, preload=True)

for i in range(10):
    start = np.random.random_integers(0,test_range)
    data2, times2 = raw2[:, start:start+chunk]
    data22, times22 = raw22[:, start:start+chunk]

    assert_array_equal(data2, data22)
    assert_array_equal(times2, times22)