GetRawData function?

I want to get the raw data from an analogwaveform channel and simply load it into an array of Doubles. Here is what I have:

Dim data() As AnalogWaveform(Of Double)
    Dim dataToFilter() As Double

    For Each WaveformGraph In WFGS
        dataToFilter(i) = data(i).GetRawData() 'Value of Type '1-dimensional array of Double' cannot be converted to 'Double'.
        WaveformGraph.PlotWaveformAppend(data(i))
        i = i + 1
    Next

Can someone please help me with the line of code in question. I need to get the raw data from the analogwaveform so that I can apply a filter to it before I stream it to a Waveformgraph.

Thanks.

Dim data() As AnalogWaveform(Of Double)
Dim dataToFilter As New List(Of Double())

Dim i As Integer = 0
For Each WaveformGraph In WFGS
    dataToFilter.Add(data(i).GetRawData())
    WaveformGraph.PlotWaveformAppend(data(i))
    i += 1
Next