mne.chpi.compute_chpi_locs¶

mne.chpi.
compute_chpi_locs
(info, chpi_amplitudes, t_step_max=1.0, too_close='raise', adjust_dig=False, verbose=None)[source]¶ Compute locations of each cHPI coils over time.
 Parameters
 infoinstance of
Info
The measurement information.
 chpi_amplitudes
dict
The timevarying cHPI coil amplitudes, with entries “times”, “proj”, and “slopes”. Typically obtained by
mne.chpi.compute_chpi_amplitudes()
. t_step_max
float
Maximum time step to use.
 too_close
str
How to handle HPI positions too close to the sensors, can be ‘raise’ (default), ‘warning’, or ‘info’.
 adjust_digbool
If True, adjust the digitization locations used for fitting based on the positions localized at the start of the file.
 verbosebool,
str
,int
, orNone
If not None, override default verbose level (see
mne.verbose()
and Logging documentation for more).
 infoinstance of
 Returns
 chpi_locs
dict
The timevarying cHPI coils locations, with entries “times”, “rrs”, “moments”, and “gofs”.
 chpi_locs
See also
Notes
This function is designed to take the output of
mne.chpi.compute_chpi_amplitudes()
and:Get HPI coil locations (as digitized in
info['dig']
) in head coords.If the amplitudes are 98% correlated with last position (and Δt < t_step_max), skip fitting.
Fit magnetic dipoles using the amplitudes for each coil frequency.
The number of fitted points
n_pos
will depend on the velocity of head movements as well ast_step_max
(andt_step_min
frommne.chpi.compute_chpi_amplitudes()
).In “auto” mode,
t_window
will be set to the longer of: Five cycles of the lowest HPI frequency.
Ensures that the frequency estimate is stable.
 The reciprocal of the smallest difference between HPI frequencies.
Ensures that neighboring frequencies can be disambiguated.
New in version 0.20.