Adding a legend with view_motifs

[kentaloupe123]

I'm plotting multiple amino acid motifs using the view_motifs function, and it appears that the coloring is based on some amino acid properties. For example, R, H, and K are all blue and positively charged amino acids.

Is there a way to add a legend with what each color represents, similar to this plot from the ggseqlogo page (https://omarwagih.github.io/ggseqlogo/) but with the multiple aligned motifs in the view_motifs plot? It even looks like the ggseqlogo may use the same coloring scheme.

[Benjamin Jean-Marie Tremblay]

Actually, these colours are indeed the exact same as the ggseqlogo ones for amino acids. You can reveal the legend with view_motifs(motif) + theme(legend.position = "right"). However, you will see that this shows all the colours for the individual letters instead of grouping them as ggseqlogo does. Unfortunately there isn't a simple way to do what you want using just view_motifs(). If you are really determined, you could extract the plot data (view_motifs(motif)$data), add an extra column to represent shared chemistry between letters, insert the adjusted data back into the ggplot object, then plot it with a custom colour scale (+scale_colour_manual(values=...)).

Apologies for the lack of satisfactory answer, if I ever find time I'll consider adding this kind of option. Until then I suppose you could copy-paste the ggseqlogo legend, or extract it and plot it alongside the view_motifs() output with cowplot.