How to plot two channels or more on the same graph?

[John]

Hi

I am trying to plot 2 channels or more on the same graph with the x-axis as the time, y-axis for two channels:
1) raw data
2) filtered data

I wish to plot (1) and (2) on the same graph to illustrate effect of filtering.

My first attempt is to do :

Code:

firstGraph.setChannel(0,1);
firstGraph.setChannel(0,2); //there is no addChannel(0,2)...
....
PhyphoxBLE::write(raw, filtered_data);

But the code above will plot only one curve.

Any idea?

John