[toc]
直接看图解释
image.png
由上图，我们可以看到，1）x横坐标与柱状图有一些距离，那么现在我们要去掉这个距离。怎么办?，2）还发现，y坐标与柱状图也是有距离的。咋去除？
接下来，我们以mtcar数据为例，展示如果去除这些间隙。
1.横坐标从0开始
首先将gear与carb转成factor
代码语言：javascript复制# libraries
library(ggthemes)
library(tidyverse)
df=mtcars %>% mutate(gear=factor(gear),
cyl=factor(cyl))
# histgram
p=ggplot(df, aes(x = gear,y=mpg, fill = cyl))
geom_bar(position="dodge", stat="identity",width=0.65)
# start from 0 in x-axis
p
scale_y_continuous(expand = c(0,0),limits = c(0,30)) 
image.png
2.纵坐标从0开始
这里有些trick，因为factor为横坐标，但是加载scale_x_continuous出错， 所以在scale_x_continuous里面，自定义x-labels。
代码语言：javascript复制df=mtcars %>% mutate(gear=(gear),
cyl=factor(cyl))
# histgram
p=ggplot(df, aes(x = gear,y=mpg, fill = cyl))
geom_bar(position="dodge", stat="identity",width=0.65)
# start from 0 in y-axis
p scale_x_continuous(expand = expansion(mult = c(0,0)))
# add x-labels
p=ggplot(df, aes(x = gear,y=mpg, fill = cyl))
geom_bar(position="dodge", stat="identity",width=0.65)
scale_x_continuous(expand = expansion(mult = c(0,0)),
breaks = c(3,4,5),
labels = c(3,4,5))
p
image.png
image.png
2.去除网格线与legend
scale_fill_manual可以更改柱状图的颜色。主题里面可去除网格线
代码语言：javascript复制p scale_y_continuous(expand = c(0,0),limits = c(0,30))
scale_fill_manual(
#expand = c(0, 0), limits = c(0, NA),
values=c("#1F78B4","#FFB300","#FA2017","#33A02C","#DD8EB4","#6A3D9A","#666666"))
theme_bw()
theme(#legend.position = "none",
axis.text.x=element_text(angle=30,hjust=1),
text = element_text(size=10,face="bold"),
plot.background = element_blank(),
panel.grid.major = element_blank(),
panel.grid.minor = element_blank(),
panel.border = element_blank(),
strip.text.y = element_blank(),
strip.text = element_text(size=10,face="bold"),
strip.background = element_blank(),
axis.line = element_line(color = 'black'))
labs(y="mpg values",
x="Gear group",fill="carb")
image.png
参考文献
- Ggplot include 0 in axis
- Starting bars and histograms at zero in ggplot2
- Force the origin to start at 0
