User Reference:LPFilter

Function

The LPFilter is a simple single-pole temporal low pass filter with a time constant $T$ (given in units of a sample's duration), a sequence $S_{in,t}$ as input and a sequence $S_{out,t}$ as output (where $t$ is an sample index proportional to time), and obeying

$S_{out,0}=(1-e^{-1/T})S_{in,0}$

$S_{out,t}=e^{-1/T}{S}_{out,t-1}+(1-e^{-1/T})S_{in,t}$

Typically, the LPFilter would be used to remove high-frequency noise from the Classifier's output.

Parameters

LPTimeConstant

The filter's time constant in units of BCI2000 data blocks, or in seconds if followed with an "s".

Consistent with its mathematical limit, a value of

LPTimeConstant= 0

disables the LPFilter.

States

None.

See also

User Reference:SourceFilter|Programming Reference:IIRFilter