I'm new to both knime and R so sorry if my question is a bit silly.
I've created a simple workflow to:
1) open multiple file and join them togheter with only one x axis (PPM) and several y axis (the name is created through the cycle from the file location)
2)plot each indivual x and y couple and save them to a specific folder (with a R snippet)
3)plot all the curve in a single plot (with a R snippet) with different line style
The last point unfortunately is not working and I don't know why.
With the release of KNIME 2.10, we now have a couple of metanodes which demonstrate how to do something similar to what you ask. If you have a look at the Grouped Scatter Plot (ggplot2) metanode and change the geometry inside the qplot by adding: geom="line", you should be able to generate something like what you are looking for.
Please report back and let us know if this works for you.