twoord.plot(lx,ly,rx,ry,data=NULL,main="",xlim=NULL,lylim=NULL,rylim=NULL,
mar=c(5,4,4,4),lcol=1,rcol=2,xlab="",lytickpos=NA,ylab="",ylab.at=NA,
rytickpos=NA,rylab="",rylab.at=NA,lpch=1,rpch=2,
type="b",xtickpos=NULL,xticklab=NULL,halfwidth=0.4,axislab.cex=1,
do.first=NULL,xaxt="s",...)
xval1 <- seq.Date(as.Date("2017-01-02"), as.Date("2017-01-10"), by="day")
xval2 <- seq.Date(as.Date("2017-01-01"), as.Date("2017-01-15"), by="day")
going_up<-seq(3,7,by=0.5)+rnorm(9)
going_down<-rev(60:74)+rnorm(15)
twoord.plot(2:10,going_up,1:15,going_down,xlab="Sequence",
ylab="Ascending values",rylab="Descending values",lcol=4,
main="Plot with two ordinates - points and lines",
do.first="plot_bg()grid(col=\"white\",lty=1)")
axis.Date(1,xval2)
library(ggplot2)
library(gtable)
library(grid)
grid.newpage()
# two plots
p1 <- ggplot(mtcars, aes(mpg, disp)) + geom_line(colour = "blue") + theme_bw()
p2 <- ggplot(mtcars, aes(mpg, drat)) + geom_line(colour = "red") + theme_bw() %+replace% theme(panel.background = element_rect(fill = NA))
# extract gtable
g1 <- ggplot_gtable(ggplot_build(p1))
g2 <- ggplot_gtable(ggplot_build(p2))
# overlap the panel of 2nd plot on that of 1st plot
pp <- c(subset(g1$layout, name == "panel", se = t:r))
g <- gtable_add_grob(g1, g2$grobs[[which(g2$layout$name == "panel")]], pp$t, pp$l, pp$b, pp$l)
# axis tweaks
ia <- which(g2$layout$name == "axis-l")
ga <- g2$grobs[[ia]]
ax <- ga$children[[2]]
ax$widths <- rev(ax$widths)
ax$grobs <- rev(ax$grobs)
ax$grobs[[1]]$x <- ax$grobs[[1]]$x - unit(1, "npc") + unit(0.15, "cm")
g <- gtable_add_cols(g, g2$widths[g2$layout[ia, ]$l], length(g$widths) - 1)
g <- gtable_add_grob(g, ax, pp$t, length(g$widths) - 1, pp$b)
# draw it
grid.draw(g)
用ggplot2画个双坐标也太难了吧。。。。
d <- data.frame(name=c("zhao","qian","sun","li"),weight=c(62,58,79,60),height=c(178,169,180,173))
x <- d$name
y1 <- d$weight
y2 <- d$height
bar <- barplot(y1,xlim=c(0,5),ylim=c(0,100),ylab="Weight",col="blue",col.axis="blue",col.lab="blue")
mtext(x,side=1,line=1,at=bar,col="black")
mtext("Name",side=1,line=3,col="black")
par(new=T) ## 创建新的画布，类似于ggplot2中的图层叠加
plot(bar,y2,axes=F,xlim=c(0,5),ylim=c(100,190),xlab="",ylab="",col="red",type="b")
axis(4,col="red",col.ticks="red",col.axis="red")
mtext("Heigth (cm)",side=4,line=3,col="red")
若画图时需要将纵坐标方向改变，可以采用取相反数的方法。正常情况下，y轴是从下往上依次增大，可以让所有数值乘以-1，使y轴从下往上依次减小，然后通过axis函数修改y轴的label。
R语言学习 绘制双坐标轴(双y轴)的方法 plotrix_瞎掰大数据_新浪博客
利用ggplot2画双坐标轴曲线
不要用gb2312, 先转换为utf-8,iconv(province.stock, to="utf-8")
htmlTreeParse处理后，再转换为
iconv(province.stock, to="gb2312")
代码如下：>install.packages（“XML”）#安装XML包
>library(XML) #载入XML包
>u<-"XXX" #写入表格所在的网址
>tbls<-readHTMLTable(u) #分析网页中的表格，如果网页包含多个表格，需要确定读取哪个表。可通过识别表的行数来确定，具体见R语言网页数据抓取的一个实例_戊甲_新浪博客
>pop<-readHTMLTable(u,which=1) #读取网页中的第一张表
>write.csv(pop,file="d:/pop.csv") #存储pop为CSV文档至D盘中
这样，就快速实现了网页中的数据爬取。
