neurodsp.filt.checks.check_filter_definition¶
- neurodsp.filt.checks.check_filter_definition(pass_type, f_range)[source]¶
Check a filter definition for validity, and get filter frequency range of the filter.
- Parameters
- pass_type{‘bandpass’, ‘bandstop’, ‘lowpass’, ‘highpass’}
Which kind of filter to apply:
‘bandpass’: apply a bandpass filter
‘bandstop’: apply a bandstop (notch) filter
‘lowpass’: apply a lowpass filter
‘highpass’ : apply a highpass filter
- f_rangetuple of (float, float) or float
Cutoff frequency(ies) used for filter, specified as f_lo & f_hi. For ‘bandpass’ & ‘bandstop’, must be a tuple. For ‘lowpass’ or ‘highpass’, can be a float that specifies pass frequency, or can be a tuple and is assumed to be (None, f_hi) for ‘lowpass’, and (f_lo, None) for ‘highpass’.
- Returns
- f_lofloat or None
The lower frequency range of the filter, specifying the highpass frequency, if specified.
- f_hifloat or None
The higher frequency range of the filter, specifying the lowpass frequency, if specified.
- Raises
- ValueError
If the filter passtype it not understood, or cutoff frequencies are incompatible.
Examples
Check a filter definition, and get the cutoff frequencies returned, if the filter is valid:
>>> f_hi, f_lo = check_filter_definition(pass_type='bandpass', f_range=(5, 25))
Check a filter definition, for an invalid filter. This example fails since a bandpass filter requires two values for
f_range
.>>> try: ... f_hi, f_lo = check_filter_definition(pass_type='bandpass', f_range=(20)) ... except ValueError: ... print("The filter definition is invalid.") The filter definition is invalid.