Parameters: 
 data : ndarray, shape (…, n_times)
The data to filter.
 sfreq : float
The sample frequency in Hz.
 l_freq : float  None
Low cutoff frequency in Hz. If None the data are only lowpassed.
 h_freq : float  None
High cutoff frequency in Hz. If None the data are only
highpassed.
 picks : arraylike of int  None
Indices of channels to filter. If None all channels will be
filtered. Currently this is only supported for
2D (n_channels, n_times) and 3D (n_epochs, n_channels, n_times)
arrays.
 filter_length : str  int
Length of the FIR filter to use (if applicable):
 ‘auto’ (default): the filter length is chosen based
on the size of the transition regions (6.6 times the reciprocal
of the shortest transition band for fir_window=’hamming’
and fir_design=”firwin2”, and half that for “firwin”).
 str: a humanreadable time in
units of “s” or “ms” (e.g., “10s” or “5500ms”) will be
converted to that number of samples if
phase="zero" , or
the shortest poweroftwo length at least that duration for
phase="zerodouble" .
 int: specified length in samples. For fir_design=”firwin”,
this should not be used.
 l_trans_bandwidth : float  str
Width of the transition band at the low cutoff frequency in Hz
(high pass or cutoff 1 in bandpass). Can be “auto”
(default in 0.14) to use a multiple of l_freq :
min(max(l_freq * 0.25, 2), l_freq)
Only used for method='fir' .
 h_trans_bandwidth : float  str
Width of the transition band at the high cutoff frequency in Hz
(low pass or cutoff 2 in bandpass). Can be “auto”
(default in 0.14) to use a multiple of h_freq :
min(max(h_freq * 0.25, 2.), info['sfreq'] / 2.  h_freq)
Only used for method='fir' .
 n_jobs : int  str
Number of jobs to run in parallel. Can be ‘cuda’ if scikits.cuda
is installed properly, CUDA is initialized, and method=’fir’.
 method : str
‘fir’ will use overlapadd FIR filtering, ‘iir’ will use IIR
forwardbackward filtering (via filtfilt).
 iir_params : dict  None
Dictionary of parameters to use for IIR filtering.
See mne.filter.construct_iir_filter for details. If iir_params
is None and method=”iir”, 4th order Butterworth will be used.
 copy : bool
If True, a copy of x, filtered, is returned. Otherwise, it operates
on x in place.
 phase : str
Phase of the filter, only used if method='fir' .
By default, a symmetric linearphase FIR filter is constructed.
If phase='zero' (default), the delay of this filter
is compensated for. If phase=='zerodouble' , then this filter
is applied twice, once forward, and once backward. If ‘minimum’,
then a minimumphase, causal filter will be used.
 fir_window : str
The window to use in FIR design, can be “hamming” (default),
“hann” (default in 0.13), or “blackman”.
 fir_design : str
Can be “firwin” (default) to use scipy.signal.firwin() ,
or “firwin2” to use scipy.signal.firwin2() . “firwin” uses
a timedomain design technique that generally gives improved
attenuation using fewer samples than “firwin2”.
..versionadded:: 0.15
 pad : str
The type of padding to use. Supports all numpy.pad() mode
options. Can also be “reflect_limited” (default), which pads with a
reflected version of each vector mirrored on the first and last
values of the vector, followed by zeros.
Only used for method='fir' .
 verbose : bool, str, int, or None
If not None, override default verbose level (see mne.verbose()
and Logging documentation for more). Defaults to
self.verbose.
