How to make a bar chart showing a negative value in R?

Question

I have data including negative value and wanna make a bar chart.

genotype<-c("A","B","C")
treatment<- c("tr1", "tr2")
y<- c(-0.124, -0.083, -0.07, 0.130, 0.216, 0.182)

data1<- data.frame (genotype, treatment, y)

   genotype treatment      y
1        A       tr1 -0.124
2        B       tr2  0.130
3        C       tr1 -0.083
4        A       tr2  0.216
5        B       tr1 -0.070
6        C       tr2  0.182

ggplot(data1, aes(x=genotype, y=y)) + 
  geom_bar (stat="identity") +
  scale_y_continuous(breaks = seq(-1,1,0.2),limits = c(-1,1))

This is the graph which I made but what I want is, like the below, to distinguish positive and negative value. Could you tell me how to do it? Many thanks!!!

Answer 1

Try this:

library(ggplot2)
#Code
ggplot(data1, aes(x=genotype, y=y,fill=treatment)) + 
  geom_bar (stat="identity",position = position_dodge(0.9)) +
  scale_y_continuous(breaks = seq(-1,1,0.2),limits = c(-1,1))

Output:

Or more customized:

#Code 2
ggplot(data1, aes(x=genotype, y=y,fill=treatment)) + 
  geom_bar (stat="identity",position = position_dodge(0.9)) +
  scale_y_continuous(breaks = seq(-1,1,0.2),limits = c(-1,1),
                     labels = scales::percent)+
  theme_bw()+
  theme(legend.position = 'bottom',
        axis.title.x = element_blank(),
        axis.text.x = element_blank(),
        axis.ticks.x = element_blank(),
        axis.text.y = element_text(color='black',face='bold'),
        legend.text = element_text(color='black',face='bold'),
        legend.title = element_text(color='black',face='bold'),
        axis.title.y = element_text(color='black',face='bold'))+
  scale_fill_manual(values=c('red','gray25'))

Output: