library('ggplot2')########################画图
library('reshape2')########################melt
A =rep( c("A","B","C","D"),each=2)
B = c(6.332968,9.368328,6.674348,4.127901,5.192845,6.652865,7.829350,6.995062)
C = c(5.367671,7.286253,5.217053,3.875520,6.679444,6.127819,5.091166,7.942029)
D = c(5.171107,6.232718,5.320568,4.924498,7.140883,4.228142,5.793514,6.347785)
E = c(5.533754,6.152393,6.113618,4.960935,5.959568,5.078903,4.871103,5.223206)
F = rep(c("sample1","sample2"),len=4)
dat = data.frame(A,B,C,D,E)
names(dat)[1] = c("type")
names(dat)[2:5]=F
dat = melt(dat,variable.name="Sample",value.name = "Num")
head(dat)

密度图

P_density=ggplot(dat,aes(x=Num))+
  geom_density(aes(fill=as.character(dat$Sample),color=as.character(dat$Sample)),alpha = 0.5,size=1,linetype="solid")+ 
##fill填充颜色，color 线条的颜色，apha 透明度,linetype线形，实线
  theme(plot.title = element_text(size = 25,face = "bold", vjust = 0.5, hjust = 0.5),
        legend.title = element_blank(),
        legend.text = element_text(size = 15, face = "bold"),
        legend.position = 'right',
        legend.key.size=unit(0.5,'cm'),
        axis.line=element_line(size = 1,color="black"),###显示x,y轴
        axis.ticks.x=element_blank(), ###取消x轴刻度线
        ###刻度标签设置，以及坐标轴titile
        axis.text.x=element_text(size = 15,face = "bold", vjust = 0.5, hjust = 0.5),
        axis.text.y=element_text(size = 15,face = "bold", vjust = 0.5, hjust = 0.5),
        axis.title.x = element_text(size = 20,face = "bold", vjust = 0.5, hjust = 0.5),
        axis.title.y = element_text(size = 20,face = "bold", vjust = 0.5, hjust = 0.5),
##取消边框背景设置 
        panel.background = element_rect(fill = "transparent",colour = NA), 
        panel.grid.minor = element_blank(), 
        panel.grid.major = element_blank(),
        plot.background = element_rect(fill = "transparent",colour = NA))
print(P_density)

两组数据直接叠加密度图

数据dat1

A =rep( c("A","B","C","D"),each=2)
B = c(6.332968,9.368328,6.674348,4.127901,5.192845,6.652865,7.829350,6.995062)
C = c(5.367671,7.286253,5.217053,3.875520,6.679444,6.127819,5.091166,7.942029)
D = c(5.171107,6.232718,5.320568,4.924498,7.140883,4.228142,5.793514,6.347785)
E = c(5.533754,6.152393,6.113618,4.960935,5.959568,5.078903,4.871103,5.223206)
F = rep(c("sample1","sample2"),len=4)
dat1 = data.frame(A,B,C,D,E)
names(dat1)[1] = c("type")
names(dat1)[2:5]=F
dat1= melt(dat1,variable.name="Sample",value.name = "Num")
head(dat1)

数据dat2

A =rep( c("A","B","C","D"),each=2)
B = c(9.944277,9.245216,8.741771,8.573114,7.953372,10.756460,7.904934,8.971346)
C = c(8.248881,9.238328,9.789772,9.800562,8.698050,9.083611,9.076143,9.650690)
D = c(9.884433,9.863561,10.756525,9.520756,8.363614,9.184047,10.004748,9.019348)
E = c(9.821923,9.430095,9.431069,8.589512,7.755056,9.935671,7.219894,9.492607)
F = rep(c("sample3","sample4"),len=4)
dat2 = data.frame(A,B,C,D,E)
names(dat2)[1] = c("type")
names(dat2)[2:5]=F
dat2 = melt(dat2,variable.name="Sample",value.name = "Num")
head(dat2)

绘图

P_density=ggplot(data=NULL)+  ##data设置NULL
  geom_density(aes(x=dat1$Num,fill=as.character(dat1$Sample),color=as.character(dat1$Sample)),alpha = 0.3,size=1,linetype="solid")+ 
#添加第二组
  geom_density(aes(x=dat2$Num,fill=as.character(dat2$Sample),color=as.character(dat2$Sample)),alpha = 0.3,size=1,linetype="solid")+
##fill填充颜色，color 线条的颜色，apha 透明度,linetype线形，实线
  labs(x="Num")+
  theme(plot.title = element_text(size = 25,face = "bold", vjust = 0.5, hjust = 0.5),
        legend.title = element_blank(),
        legend.text = element_text(size = 15, face = "bold"),
        legend.position = 'right',
        legend.key.size=unit(0.5,'cm'),
        axis.line=element_line(size = 1,color="black"),###显示x,y轴
        axis.ticks.x=element_blank(), ###取消x轴刻度线
        ###刻度标签设置，以及坐标轴titile
        axis.text.x=element_text(size = 15,face = "bold", vjust = 0.5, hjust = 0.5),
        axis.text.y=element_text(size = 15,face = "bold", vjust = 0.5, hjust = 0.5),
        axis.title.x = element_text(size = 20,face = "bold", vjust = 0.5, hjust = 0.5),
        axis.title.y = element_text(size = 20,face = "bold", vjust = 0.5, hjust = 0.5),
##取消边框背景设置 
        panel.background = element_rect(fill = "transparent",colour = NA), 
        panel.grid.minor = element_blank(), 
        panel.grid.major = element_blank(),
        plot.background = element_rect(fill = "transparent",colour = NA))
print(P_density)

如果想提升自己的绘图技能，我们推荐：R语言绘图基础（ggplot2)

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