我需要给 plot 添加渐变色

Question

I want to add gradient colour to the plot.

Here is the data:

Name	WT1	MUT1	WT2	MUT2
DNA damage	50	40	45	5
Telomerase	60	55	55	2
DNA repair	90	80	80	4
Envelope repair	45	30	35	6

It tried the above data using the following code:

library("ggplot2")
library(tidyverse)
top_fun <- read.delim(file="TEST2.txt",header = TRUE)

topfun <- as.data.frame(top_fun)

topfun %>%
  pivot_longer(-Name) %>%
  ggplot(aes(x = Name, y = value, fill = name)) +
  geom_col(position = position_stack(), color="black")+
  coord_flip() +facet_wrap(~name)+facet_grid(~name)+
  theme(axis.text = element_text(size=13))

The plot which created looks like this:

I need to add gradient colour to this plot. Thank you for the help!

Answer 1

I may be misunderstanding what you are looking for, but I think you are looking for a graduated fill within each bar. There is no option to create a gradient fill like this natively in ggplot, so you would have to create the effect yourself:

topfun %>%
  pivot_longer(-Name) %>%
  ggplot(aes(x = Name, y = value, fill = name)) +
  geom_col(position = position_stack(), color="black") +
  geom_col(data = . %>% tidyr::uncount(weight = value) %>%
             group_by(Name, name) %>% mutate(rn = row_number()),
           aes(y = 1, alpha = 1 - rn/75,
               color = after_scale(alpha('white', alpha))), 
           position = position_stack(), fill = 'white') +
  geom_col(position = position_stack(), fill = NA, color = "black") +
  coord_flip() + 
  facet_grid(~name) + 
  theme(axis.text = element_text(size = 13)) +
  scale_alpha_continuous(range = c(0, 0.4), guide = 'none')

Answer 2

You could try this, which will put a gradient across all the bars. This changes the fill command in aes from Name to value and adds a scale_fill_gradient . Here I chose blue to red but those can be changed to desired colors.

Data

topfun <- read.table(text = "Name   WT1 MUT1    WT2 MUT2
DNA_damage  50  40  45  5
Telomerase  60  55  55  2
DNA_repair  90  80  80  4
Envelope_repair 45  30  35  6", header = TRUE)

Code

library(ggplot2)
library(tidyr)
topfun %>%
  pivot_longer(-Name) %>%
  ggplot(aes(x = Name, y = value, fill = value)) +
  geom_bar(stat = "identity", color = "black")+
  coord_flip() +facet_wrap(~name)+facet_grid(~name)+
  theme(axis.text = element_text(size=13)) +
  scale_fill_gradient(low = "blue", high = "red")