I have a dataframe with 3 columns and I create an arc diagram ( source x target).
I don’t know how to colour my edge with st_disease.

Here is my code :

links <- data.frame(
source = c("Convalescent plasma", "Convalescent whole blood", "Gentamicin", "Interferon β-1a", "Lopinavir/ritonavir and recombinant IFN-β1b", "MAb114", "Plasma", "Plasma", "REGN-EB3", "Remdesivir", "Ribavirin", "Ribavirin", "Ribavirin", "Ribavirin", "Ribavirin", "Ribavirin", "Tecovirimat", "ZMapp"),
target = c("No active treatment", "No active treatment", "Doxycycline", "No active treatment", "No active treatment", "ZMapp", "No active treatment", "No active treatment", "ZMapp", "ZMapp", "No active treatment", "No active treatment", "No active treatment", "No active treatment", "No active treatment", "No active treatment", "No active treatment", "Favipiravir"),
st_disease = c("Ebola", "Ebola", "Plague", "Ebola", "MERS", "Ebola", "Lassa fever", "Lassa fever", "Ebola", "Ebola", "Nipah", "Crimean Congo Haemorrhagic Fever", "Crimean Congo Haemorrhagic Fever", "Lassa fever", "Lassa fever", "Lassa fever", "Mpox", "Ebola")
)

mygraph <- graph_from_data_frame(links)
p2 <- ggraph(mygraph, layout="linear") +
geom_edge_arc0(edge_colour="#69b3a2",
edge_alpha=0.3,
edge_width=1.5) +
geom_node_point( color="#69b3a2", size=5, position = "identity") +
geom_node_text( aes(label=name), repel = TRUE, size=4, color="black", nudge_y=-0.5 ,angle=70, vjust=1) +
scale_edge_color_manual(values = col)+
theme_void() +
theme(
legend.position="none",
# plot.margin=unit(rep(2,4), "cm")
plot.margin=unit(c(4,2,2,2), "cm"))+
coord_cartesian(clip = "off")

p2

I tried to change edge_colour but I dot not understand why it’s asking a Aesthetics of length 72.