filterTimeSeries
Filter signal using the Kaiser windowing method.
Syntax
filtered_signal = filterTimeSeries(kgrid, medium, signal) filtered_signal = filterTimeSeries(kgrid, medium, signal, ...)
Description
filterTimeSeries filters an input time domain signal using a low pass filter applied by applyFilter with a specified cut-off frequency, stop-band attenuation, and transition bandwidth. It uses the Kaiser Windowing method to design the FIR filter, which can be implemented as either a zero phase or linear phase filter. The cutoff frequency is defined by a minimum number of points per wavelength. A smoothing ramp can also be applied to the beginning of the signal to reduce high frequency transients.
Inputs
kgrid |
k-Wave grid object returned by kWaveGrid |
medium |
k-Wave medium structure |
signal |
the time domain signal to filter |
Optional Inputs
Optional 'string', value pairs that may be used to modify the default computational settings.
| Input | Valid Settings | Default | Description |
|---|---|---|---|
'PlotSignals' |
(Boolean scalar) | false |
Boolean controlling whether the time signal is displayed before and after filtering. |
'PlotSpectrums' |
(Boolean scalar) | false |
Boolean controlling whether the amplitude spectrum is displayed before and after filtering. |
'PPW' |
(integer numeric scalar) | 3 |
The number of points per wavelength used to compute the filter cutoff frequency (setting to 0 turns off the filtering). |
'RampPPW' |
(integer numeric scalar) | 0 |
The number of points per wavelength used to compute the length of the cosine start-up ramp (setting to 0 turns off the start-up ramp). |
'StopBandAtten' |
(numeric scalar) | 60 |
Attenuation in decibels in the filter stop band. |
'TransitionWidth' |
(numeric scalar) | 0.1 |
Size of the transition relative to the temporal sampling frequency. |
'ZeroPhase' |
(Boolean scalar) | false |
Boolean controlling whether a causal or zero phase filter is applied. |
Outputs
filtered_signal |
the filtered time signal |
Examples
- Monopole Point Source In A Homogeneous Propagation Medium
- Dipole Point Source In A Homogeneous Propagation Medium
- Simulating Transducer Field Patterns
- The Doppler Effect
- Diffraction Through A Slit
- Simulations In Three-Dimensions
- Focussed Detector in 3D
- Modelling Sensor Directivity in 2D
- Modelling Sensor Directivity in 3D
- Focussed 2D Array with Directional Elements
- Filtering A Delta Function Input Signal
See Also
applyFilter, smooth, spectrum