I am putting together a figure using the Gviz package. I noticed that the arrow heads (showing the orientation of the transcript) from the GeneRegionTrack output are very small and somewhat difficult to see. I tried increasing the line size (using lwd=“#”), however the arrows themselves do not seem to increase in size. Is there currently any way in which I could modify the size of the arrows to make them more visible ? 

Anyone have any suggestions?

Thanks!

You could try the min.height display parameter. Choosing a larger value there should increase the arrow head sizes.

data(cyp2b10)
grTrack <- GeneRegionTrack(cyp2b10)
plotTracks(grTrack)
grTrack <- GeneRegionTrack(cyp2b10, min.height=10)
plotTracks(grTrack)

Thanks Florian works great!