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"""
============================
Export Raw Objects to NiTime
============================
This script shows how to export raw files to the NiTime library
for further signal processing and data analysis.
"""
# Author: Denis Engemann <denis.engemann@gmail.com>
#
# License: BSD (3-clause)
print(__doc__)
import numpy as np
import mne
from mne.io import Raw
from mne.datasets import sample
data_path = sample.data_path()
raw_fname = data_path + '/MEG/sample/sample_audvis_filt-0-40_raw.fif'
###############################################################################
# get raw data
raw = Raw(raw_fname)
# set picks
picks = mne.pick_types(raw.info, meg=True, eeg=False, eog=False,
stim=False, exclude='bads')
# pick times relative to the onset of the MEG measurement.
start, stop = raw.time_as_index([100, 115], use_first_samp=False)
# export to nitime using a copy of the data
raw_ts = raw.to_nitime(start=start, stop=stop, picks=picks, copy=True)
###############################################################################
# explore some nitime timeseries features
# get start
print(raw_ts.t0)
# get duration
print(raw_ts.duration)
# get sample duration (sampling interval)
print(raw_ts.sampling_interval)
# get exported raw infor
print(list(raw_ts.metadata.keys()))
# index at certain time
print(raw_ts.at(110.5))
# get channel names (attribute added during export)
print(raw_ts.ch_names[:3])
###############################################################################
# investigate spectral density
import matplotlib.pyplot as plt
import nitime.algorithms as tsa
ch_sel = raw_ts.ch_names.index('MEG 0122')
data_ch = raw_ts.data[ch_sel]
f, psd_mt, nu = tsa.multi_taper_psd(data_ch, Fs=raw_ts.sampling_rate,
BW=1, adaptive=False, jackknife=False)
# Convert PSD to dB
psd_mt = 10 * np.log10(psd_mt)
plt.close('all')
plt.plot(f, psd_mt)
plt.xlabel('Frequency (Hz)')
plt.ylabel('Power Spectrald Density (db/Hz)')
plt.title('Multitaper Power Spectrum \n %s' % raw_ts.ch_names[ch_sel])
plt.show()
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