# -----------------------------------------------------------------------------
# Apply RESS
out, maps, _ = ress.RESS(data, sfreq=sfreq, peak_freq=target, return_maps=True)
# Compute PSD
nfft = 250
df = sfreq / nfft # frequency resolution
bins, psd = ss.welch(out.squeeze(1),
sfreq,
window="hamming",
nperseg=nfft,
noverlap=125,
axis=0)
psd = psd.mean(axis=1, keepdims=True) # average over trials
snr = snr_spectrum(psd, bins, skipbins=2, n_avg=2)
f, ax = plt.subplots(1)
ax.plot(bins, snr, 'o', label='SNR')
ax.plot(bins[bins == target], snr[bins == target], 'ro', label='Target SNR')
ax.axhline(1, ls=':', c='grey', zorder=0)
ax.axvline(target, ls=':', c='grey', zorder=0)
ax.set_ylabel('SNR (a.u.)')
ax.set_xlabel('Frequency (Hz)')
ax.set_xlim([0, 40])
###############################################################################
# Project components back into sensor space to see the effects of RESS on the
# average SSVEP.
proj = matmul3d(out, maps)
def test_ress(target, n_trials, show=False):
"""Test RESS."""
sfreq = 250
data, source = create_data(n_times=1000,
n_trials=n_trials,
freq=target,
sfreq=sfreq,
show=False)
out = ress.RESS(data, sfreq=sfreq, peak_freq=target)
nfft = 500
bins, psd = ss.welch(out.squeeze(1),
sfreq,
window="boxcar",
nperseg=nfft,
noverlap=0,
axis=0,
average='mean')
# psd = np.abs(np.fft.fft(out, nfft, axis=0))
# psd = psd[0:psd.shape[0] // 2 + 1]
# bins = np.linspace(0, sfreq // 2, psd.shape[0])
# print(psd.shape)
# print(bins[:10])
psd = psd.mean(axis=-1, keepdims=True) # average over trials
snr = snr_spectrum(psd + psd.max() / 20, bins, skipbins=1, n_avg=2)
# snr = snr.mean(1)
if show:
f, ax = plt.subplots(2)
ax[0].plot(bins, snr, ':o')
ax[0].axhline(1, ls=':', c='grey', zorder=0)
ax[0].axvline(target, ls=':', c='grey', zorder=0)
ax[0].set_ylabel('SNR (a.u.)')
ax[0].set_xlabel('Frequency (Hz)')
ax[0].set_xlim([0, 40])
ax[0].set_ylim([0, 10])
ax[1].plot(bins, psd)
ax[1].axvline(target, ls=':', c='grey', zorder=0)
ax[1].set_ylabel('PSD')
ax[1].set_xlabel('Frequency (Hz)')
ax[1].set_xlim([0, 40])
# plt.show()
assert snr[bins == target] > 10
assert (snr[(bins <= target - 2) | (bins >= target + 2)] < 2).all()
# test multiple components
out, maps = ress.RESS(data,
sfreq=sfreq,
peak_freq=target,
n_keep=1,
return_maps=True)
_ = ress.RESS(data, sfreq=sfreq, peak_freq=target, n_keep=2)
_ = ress.RESS(data, sfreq=sfreq, peak_freq=target, n_keep=-1)
proj = matmul3d(out, maps.T)
assert proj.shape == data.shape
if show:
f, ax = plt.subplots(data.shape[1], 2, sharey='col')
for c in range(data.shape[1]):
ax[c, 0].plot(data[:, c].mean(-1), lw=.5, label='data')
ax[c, 1].plot(proj[:, c].mean(-1), lw=.5, label='projection')
if c < data.shape[1]:
ax[c, 0].set_xticks([])
ax[c, 1].set_xticks([])
ax[0, 0].set_title('Before')
ax[0, 1].set_title('After')
plt.legend()
plt.show()
def test_ress(target, n_trials, peak_width, neig_width, neig_freq, show=False):
"""Test RESS."""
sfreq = 250
n_keep = 1
n_chans = 10
n_times = 1000
data, source = create_data(n_times=n_times,
n_trials=n_trials,
n_chans=n_chans,
freq=target,
sfreq=sfreq,
show=False)
out = ress.RESS(data,
sfreq=sfreq,
peak_freq=target,
neig_freq=neig_freq,
peak_width=peak_width,
neig_width=neig_width,
n_keep=n_keep)
nfft = 500
bins, psd = ss.welch(out.squeeze(1),
sfreq,
window="boxcar",
nperseg=nfft / (peak_width * 2),
noverlap=0,
axis=0,
average='mean')
# psd = np.abs(np.fft.fft(out, nfft, axis=0))
# psd = psd[0:psd.shape[0] // 2 + 1]
# bins = np.linspace(0, sfreq // 2, psd.shape[0])
# print(psd.shape)
# print(bins[:10])
psd = psd.mean(axis=-1, keepdims=True) # average over trials
snr = snr_spectrum(psd + psd.max() / 20, bins, skipbins=1, n_avg=2)
# snr = snr.mean(1)
if show:
f, ax = plt.subplots(2)
ax[0].plot(bins, snr, ':o')
ax[0].axhline(1, ls=':', c='grey', zorder=0)
ax[0].axvline(target, ls=':', c='grey', zorder=0)
ax[0].set_ylabel('SNR (a.u.)')
ax[0].set_xlabel('Frequency (Hz)')
ax[0].set_xlim([0, 40])
ax[0].set_ylim([0, 10])
ax[1].plot(bins, psd)
ax[1].axvline(target, ls=':', c='grey', zorder=0)
ax[1].set_ylabel('PSD')
ax[1].set_xlabel('Frequency (Hz)')
ax[1].set_xlim([0, 40])
# plt.show()
assert snr[bins == target] > 10
assert (snr[(bins <= target - 2) | (bins >= target + 2)] < 2).all()
# test multiple components
out, fromress, toress = ress.RESS(data,
sfreq=sfreq,
peak_freq=target,
neig_freq=neig_freq,
peak_width=peak_width,
neig_width=neig_width,
n_keep=n_keep,
return_maps=True)
proj = matmul3d(out, fromress)
assert proj.shape == (n_times, n_chans, n_trials)
if show:
f, ax = plt.subplots(data.shape[1], 2, sharey='col')
for c in range(data.shape[1]):
ax[c, 0].plot(data[:, c].mean(-1), lw=.5, label='data')
ax[c, 1].plot(proj[:, c].mean(-1), lw=.5, label='projection')
if c < data.shape[1]:
ax[c, 0].set_xticks([])
ax[c, 1].set_xticks([])
ax[0, 0].set_title('Before')
ax[0, 1].set_title('After')
plt.legend()
# 2 comps
_ = ress.RESS(data, sfreq=sfreq, peak_freq=target, n_keep=2)
# All comps
out, fromress, toress = ress.RESS(data,
sfreq=sfreq,
peak_freq=target,
n_keep=-1,
return_maps=True)
if show:
# Inspect mixing/unmixing matrices
combined_data = np.array([toress, fromress, pinv(toress)])
_max = np.amax(combined_data)
f, ax = plt.subplots(3)
ax[0].imshow(toress, label='toRESS')
ax[0].set_title('toRESS')
ax[1].imshow(fromress, label='fromRESS', vmin=-_max, vmax=_max)
ax[1].set_title('fromRESS')
ax[2].imshow(pinv(toress), vmin=-_max, vmax=_max)
ax[2].set_title('toRESS$^{-1}$')
plt.tight_layout()
plt.show()
print(np.sum(np.abs(pinv(toress) - fromress) >= .1))