R ggplot viridis change the color gradient

Question

Hello I am plotting scatter plot using R ggplot for coloring using virdis, I wanted split the color legend to get more contrast between ranges currently legend having 1000,2000,3000,4000 In between this split this to get more color currently my code looking as below

library(dplyr)
library(ggplot2)
library("viridis")

df <- tibble(gene   = sample.int(5000),aceth  = rnorm(5000),acvitd = rnorm(5000))
df$log_mean=log(df$gene)
p=ggplot(df, aes(aceth, acvitd))+
  geom_point(aes(color =gene)) +
  theme(legend.position = "top")+
  theme(panel.grid.major = element_blank(), panel.grid.minor = element_blank(),
        panel.background = element_blank(), axis.line = element_line(colour = "black"))

p=p+ theme(legend.position = "top") +
     scale_color_viridis(option = "A",
     name = "mean",
     guide = guide_colourbar(direction = "horizontal",
     barheight = unit(4, units = "mm"),
     barwidth = unit(100, units = "mm"),
     draw.ulim = F,
     title.hjust = 0.5,
     label.hjust = 0.5, title.position = "top"))

How I wanted my graph look like

can anyone suggest me

Answer 1

Perhaps you're looking for scale_colour_vridis_b to bin your colours?

df <- tibble(gene   = sample.int(5000),aceth  = rnorm(5000),acvitd = rnorm(5000))
df$log_mean=log(df$gene)
p=ggplot(df, aes(aceth, acvitd))+
  geom_point(aes(color = - (aceth + acvitd))) +
  theme(legend.position = "top")+
  theme(panel.grid.major = element_blank(), panel.grid.minor = element_blank(),
        panel.background = element_blank(), axis.line = element_line(colour = "black"))

p+ theme(legend.position = "top") +
     scale_colour_viridis_b(option = "A", values = 0:10 /10, breaks = 0:5 - 2.5)