filter_fir :
A finite impulse response filter.
The filter_fir primitive is a discrete-time filter with a finite impulse response. It decides the output value based on N previous inputs and its discrete-time impulse response as follows:
out[n] = data[0]*x[n] + data[1]*x[n-1] + ... + data[N-1]*x[n-N+1] where x[n] = -0.5 for in[n] = 0 0.5 for in[n] = 1 
Input/Output Terminals
| Name | I/O | Type | Description | 
| out | output | xreal | analog output | 
| in | input | xbit | digital input | 
| trig | input | xbit | trigger input | 
Parameters
| Name | Type | Default | Unit | Description | 
| data | real array | ‘{1.0} | None | filter coefficients | 
| tran_time | real | 0.0 | seconds | transition time |