Commit 8f354b4f authored by Christian Brodbeck's avatar Christian Brodbeck

ENH: interpolate between time points

To achieve specified framerate and time_dilation in Brain.save_movie()
parent 6df02e2f
......@@ -29,14 +29,12 @@ for hemi in ['lh', 'rh']:
data = stc['data']
"""
time points in milliseconds
Calculate sample time points
"""
time = 1e3 * np.linspace(stc['tmin'],
stc['tmin'] + data.shape[1] * stc['tstep'],
data.shape[1])
times = np.arange(data.shape[1]) * stc['tstep'] + stc['tmin']
brain.add_data(data, colormap='hot', vertices=stc['vertices'],
smoothing_steps=10, time=time, time_label='time=%0.2f ms',
smoothing_steps=10, time=times, time_label='%0.3f s',
hemi=hemi)
"""
......@@ -45,11 +43,13 @@ scale colormap
brain.scale_data_colormap(fmin=13, fmid=18, fmax=22, transparent=True)
"""
Save movies with different combinations of views
"""
brain.save_movie('example_current.mov')
brain.save_movie('example_single.mov', montage='single')
brain.save_movie('example_h.mov', montage=['lat', 'med'], orientation='h')
brain.save_movie('example_v.mov', montage=[['lat'], ['med']])
Save movies with different combinations of views. Use a large value for
time_dilation because the sample stc only covers 30 ms
"""
brain.save_movie('example_current.mov', time_dilation=30)
brain.save_movie('example_single.mov', time_dilation=30, montage='single')
brain.save_movie('example_h.mov', time_dilation=30, montage=['lat', 'med'],
orientation='h')
brain.save_movie('example_v.mov', time_dilation=30, montage=[['lat'], ['med']])
brain.close()
......@@ -218,14 +218,9 @@ def test_movie():
stc_fname = os.path.join(data_dir, 'meg_source_estimate-lh.stc')
stc = io.read_stc(stc_fname)
data = stc['data']
vertices = stc['vertices']
time = 1e3 * np.linspace(stc['tmin'],
stc['tmin'] + data.shape[1] * stc['tstep'],
data.shape[1])
colormap = 'hot'
time_label = 'time=%0.2f ms'
brain.add_data(data, colormap=colormap, vertices=vertices,
smoothing_steps=10, time=time, time_label=time_label)
time = np.arange(data.shape[1]) * stc['tstep'] + stc['tmin']
brain.add_data(data, colormap='hot', vertices=stc['vertices'],
smoothing_steps=10, time=time, time_label='time=%0.2f ms')
brain.scale_data_colormap(fmin=13, fmid=18, fmax=22, transparent=True)
# save movies with different options
......@@ -233,7 +228,7 @@ def test_movie():
try:
dst = os.path.join(tempdir, 'test')
brain.save_movie(dst, montage='current')
brain.save_movie(dst, montage='current', tstart=time[1], tstop=time[-1])
brain.save_movie(dst, montage='current', tmin=0.081, tmax=0.102)
brain.save_movie(dst, montage='single')
# brain.save_movie(dst, montage=['lat', 'med'], orientation='v')
# brain.save_movie(dst, montage=[['lat'], ['med']])
......
......@@ -5,6 +5,7 @@ from warnings import warn
import numpy as np
from scipy import stats, ndimage, misc
from scipy.interpolate import interp1d
from matplotlib.colors import colorConverter
import nibabel as nib
......@@ -1542,13 +1543,16 @@ class Brain(object):
data["transparent"] = transparent
self._toggle_render(True, views)
def set_data_time_index(self, time_idx):
def set_data_time_index(self, time_idx, interpolation='linear'):
"""Set the data time index to show
Parameters
----------
time_idx : int
time index
time_idx : int | float
Time index. Floats will cause samples to be interpolated.
interpolation : str
Interpolation method (``scipy.interpolate.interp1d`` parameter,
default 'linear').
"""
if self.n_times is None:
raise RuntimeError('cannot set time index with no time data')
......@@ -1559,7 +1563,14 @@ class Brain(object):
for hemi in ['lh', 'rh']:
data = self.data_dict[hemi]
if data is not None:
plot_data = data["array"][:, time_idx]
# interpolation
if isinstance(time_idx, float):
times = np.arange(self.n_times)
ifunc = interp1d(times, data['array'], interpolation, 1)
plot_data = ifunc(time_idx)
else:
plot_data = data["array"][:, time_idx]
if data["smooth_mat"] is not None:
plot_data = data["smooth_mat"] * plot_data
for surf in data["surfaces"]:
......@@ -1568,7 +1579,11 @@ class Brain(object):
# Update time label
if data["time_label"]:
time = data["time"][time_idx]
if isinstance(time_idx, float):
ifunc = interp1d(times, data['time'])
time = ifunc(time_idx)
else:
time = data["time"][time_idx]
self.update_text(data["time_label"] % time, "time_label")
self._toggle_render(True, views)
......@@ -1932,7 +1947,8 @@ class Brain(object):
def save_image_sequence(self, time_idx, fname_pattern, use_abs_idx=True,
row=-1, col=-1, montage='single', orientation='h',
border_size=15, colorbar='auto'):
border_size=15, colorbar='auto',
interpolation='linear'):
"""Save a temporal image sequence
The files saved are named "fname_pattern % (pos)" where "pos" is a
......@@ -1966,6 +1982,9 @@ class Brain(object):
For 'auto', the colorbar is shown in the middle view (default).
For int or list of int, the colorbar is shown in the specified
views. For ``None``, no colorbar is shown.
interpolation : str
Interpolation method (``scipy.interpolate.interp1d`` parameter,
default 'linear').
Returns
-------
......@@ -1976,7 +1995,7 @@ class Brain(object):
images_written = list()
rel_pos = 0
for idx in time_idx:
self.set_data_time_index(idx)
self.set_data_time_index(idx, interpolation)
fname = fname_pattern % (idx if use_abs_idx else rel_pos)
if montage == 'single':
self.save_single_image(fname, row, col)
......@@ -2068,9 +2087,9 @@ class Brain(object):
cb.visible = colorbars_visibility[cb]
return out
def save_movie(self, fname, tstart=None, tstop=None, step=1,
time_idx=None, montage='current', orientation='h',
border_size=15, colorbar='auto', framerate=10,
def save_movie(self, fname, time_dilation=4., tmin=None, tmax=None,
interpolation='linear', montage='current', orientation='h',
border_size=15, colorbar='auto', framerate=25,
codec='mpeg4', row=-1, col=-1):
"""Save a movie (for data with a time axis)
......@@ -2078,18 +2097,17 @@ class Brain(object):
----------
fname : str
Path at which to save the movie.
tstart : None | float
time_dilation : float
Factor by which to stretch time (default 4). For example, an epoch
from -100 to 600 ms lasts 700 ms. With ``time_dilation=4`` this
would result in a 2.8 s long movie.
tmin : float
First time point to include (default: all data).
tstop : None | float
Time point at which to stop the movie (exclusive; default: all
data).
step : int
Number of data frames to step forward between movie frames
(default 1).
time_idx : None | array
Index that selects time points form the time axis from which to
make the movie. If time_idx is specified, neither of tstart, tstop
or tstep should be specified.
tmax : float
Last time point to include (default: all data).
interpolation : str
Interpolation method (``scipy.interpolate.interp1d`` parameter,
default 'linear').
montage: 'current' | 'single' | list
Views to include in the images: 'current' (default) uses the
currently displayed image; 'single' uses a single view, specified
......@@ -2105,7 +2123,7 @@ class Brain(object):
For int or list of int, the colorbar is shown in the specified
views. For ``None``, no colorbar is shown.
framerate : float
Framerate of the movie (frames per second).
Framerate of the movie (frames per second, default 25).
codec : str
Codec to use (default 'mpeg4').
row : int
......@@ -2119,36 +2137,40 @@ class Brain(object):
"downlaoded from http://ffmpeg.org/download.html.")
raise RuntimeError(err)
if tstart is not None:
start = self.index_for_time(tstart, rounding='up')
else:
start = 0
if tstop is not None:
stop = self.index_for_time(tstop, rounding='up')
else:
stop = self.n_times
if all(x is None for x in (tstart, tstop, step)):
if time_idx is None:
time_idx = np.arange(self.n_times)
elif time_idx is None:
time_idx = np.arange(start, stop, step)
if tmin is None:
tmin = self._times[0]
elif tmin < self._times[0]:
raise ValueError("tmin=%r is smaller than the first time point "
"(%r)" % (tmin, self._times[0]))
if tmax is None:
tmax = self._times[-1]
elif tmax >= self._times[-1]:
raise ValueError("tmax=%r is greater than the latest time point "
"(%r)" % (tmax, self._times[-1]))
# find indexes at which to create frames
tstep = 1. / (framerate * time_dilation)
if (tmax - tmin) % tstep == 0:
tstop = tmax + tstep / 2.
else:
err = ("Both slice parameters (tstart, tstop, step) and "
"time_idx can not be specified at the same time.")
raise TypeError(err)
tstop = tmax
times = np.arange(tmin, tstop, tstep)
interp_func = interp1d(self._times, np.arange(self.n_times))
time_idx = interp_func(times)
n_times = len(time_idx)
if n_times == 0:
raise ValueError("No time points selected")
logger.debug("Save movie for time points/samples\n%s\n%s"
% (times, time_idx))
tempdir = mkdtemp()
frame_pattern = 'frame%%0%id.png' % (np.floor(np.log10(n_times)) + 1)
fname_pattern = os.path.join(tempdir, frame_pattern)
self.save_image_sequence(time_idx, fname_pattern, False, row,
col, montage, orientation, border_size,
colorbar)
colorbar, interpolation)
ffmpeg(fname, fname_pattern, framerate, codec)
def animate(self, views, n_steps=180., fname=None, use_cache=False,
......
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