library(ggplot2)
library(knitr)
library(grid)
kable(mtcars[1:5,])
mpg cyl disp hp drat wt qsec vs am gear carb
Mazda RX4 21.0 6 160 110 3.90 2.620 16.46 0 1 4 4
Mazda RX4 Wag 21.0 6 160 110 3.90 2.875 17.02 0 1 4 4
Datsun 710 22.8 4 108 93 3.85 2.320 18.61 1 1 4 1
Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
Hornet Sportabout 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2
p<-ggplot(mtcars,aes(disp,hp,fill=factor(am)))+geom_bar(stat='identity',width=10,alpha=.9)+theme(legend.position='none')
p1<-p+ggtitle('This is a title')+theme(plot.title=element_text(colour = 'red'))
p2<-p+ggtitle('This is a title')
p3<-p+ggtitle('This is a title')+
  theme(plot.title=element_text(family = "Courier"))#无衬线'Helvetica',衬线'Times',等宽'Courier'
p4<-p+ggtitle('This is a title')+
  theme(plot.title=element_text(face = 'bold.italic'))#普通'plain'粗体'bold'斜体'italic'

p1<-p+ggtitle('This is a title')+theme(plot.title=element_text(size = 30))
p2<-p+ggtitle('This is a title')+
  theme(plot.title=element_text(hjust = .8))#介于0,1之间,调节标题的横向位置
p3<-p+ggtitle('This is a title')+
  theme(plot.title=element_text(vjust = 0 ))##介于0,1之间,调节标题的纵向位置,但是没有起作用?
p4<-p+ggtitle('This is a title')+
    theme(plot.title=element_text(angle = 180))
#p5<-p+ggtitle("This is title\nsecond title\nthired #title")+
#  theme(plot.title=element_text(lineheight = 1.5))#调节行间距

p1<-p+theme(plot.background=element_rect(fill='gold'))
p2<-p+theme(plot.background=element_rect(fill='white',colour='red'))
p3<-p+theme(plot.background=element_rect(fill='white',colour='red',size = 3))
p4<-p+theme(plot.background=element_rect(fill='white',colour='red',size = 3,linetype = 3))

p1<-p+theme(plot.background=element_rect(colour='blue'),panel.background=element_rect(colour='red',fil='white',size = 2))
p2<-p+theme(panel.grid.minor=element_line(colour='white'),panel.background=element_rect(fill='white'))
#p3<-p+theme(plot.background=element_rect(colour='blue'),panel.background=element_rect(colour='red',fil='white',size = 2),panel.border=element_rect(colour='lightblue'))
#调整主网格线
p3<-p+theme(panel.grid.major=element_line(colour='black'))
#调整次要网格线
p4<-p+theme(panel.grid.minor=element_line(colour='gray'),panel.background=element_rect(fill='white'))

p1<-p+theme(axis.title=element_text(colour='red'))
p2<-p+theme(axis.title.x=element_text(colour='red'),axis.title.y=element_text(colour='blue'))
p3<-p+theme(axis.text=element_text(colour='purple'))
p4<-p+theme(axis.text.x=element_text(colour='purple'),axis.text.y=element_text(colour='green'))

p1<-p+theme(axis.ticks.length=unit(.5,"lines"))
p2<-p+theme(axis.ticks.length=unit(-.5,"lines"))
p3<-p+theme(axis.line=element_line(colour='red',linetype = 5,size=2))
#调通axis.line.x(y)之前必须定义axis.line
p4<-p+theme(axis.line=element_line(colour='red',linetype = 2,size=2),axis.line.y=element_line(colour='blue',linetype = 2,size=1))