volcani plot r ggplot2
# Add colour, size and alpha (transparency) to volcano plot --------------------
cols <- c("up" = "#ffad73", "down" = "#26b3ff", "ns" = "grey")
sizes <- c("up" = 2, "down" = 2, "ns" = 1)
alphas <- c("up" = 1, "down" = 1, "ns" = 0.5)
diseased_vs_healthy %>%
ggplot(aes(x = log2(fold_change),
y = -log10(adj_p_val),
fill = gene_type,
size = gene_type,
alpha = gene_type)) +
geom_point(shape = 21, # Specify shape and colour as fixed local parameters
colour = "black") +
geom_hline(yintercept = -log10(0.05),
linetype = "dashed") +
geom_vline(xintercept = c(log2(0.5), log2(2)),
linetype = "dashed") +
scale_fill_manual(values = cols) + # Modify point colour
scale_size_manual(values = sizes) + # Modify point size
scale_alpha_manual(values = alphas) + # Modify point transparency
scale_x_continuous(breaks = c(seq(-10, 10, 2)),
limits = c(-10, 10))