当我创建下面的绘图时,我会在绘图区域和轴之间产生不需要的空间(即蓝色框和x轴之间的空白区域.如何删除此空间并使绘图区域与绘图轴齐平?谢谢.
xleft<-c(1,2,2.5)
xright<-c(2,2.5,2.75)
ybottom<-c(1,2,2.5)
ytop<-c(2,2.5,2.75)
par(mar = c(15,15,2.75,2.75) + 0.1)
plot(c(1,2.75),c(1,2.75),type="n",main="title",xlab="site.x",ylab="ylab")
rect(xleft,ybottom,xright,ytop,col=c("blue","red","green"))
#Label position along  axes
x.label.position<-(xleft+xright)/2
y.label.position<-(ybottom+ytop)/2
 #Labels
 x.label<-c("Long species Name1","Long species Name2","Long species Name3")
 y.label<-c("Long species Name4","Long species Name5","Long species Name5")
 text(par()$usr[1]-0.5,y.label.position,y.label,xpd=TRUE,adj=1)
 text(y=par()$usr[3]-0.5,x=x.label.position,x.label,xpd=TRUE,adj=1,srt=90)
 par(xpd=TRUE)
 legend(-0.1,0,legend=c("Species A","Species B","Species C"),fill=c("blue", "red", "green"))

更新我尝试了plannapus的建议和我的实际数据,但是只能让y轴行为是否在这块代码中还有其他一些东西给绘图区域的边增加了空间?
quartz("colour.plot")
par(mar=c(15,15,4,2)+0.1)#sets margins of plotting area
#create the data plot
    plot(c(0,100), c(0,100), type = "n", main = paste(x,"vs",y," -",depth),xlab=paste("Species composition in remainder ",x),ylab=paste("Species composition in remainder ",y),asp=1,xaxs="i",yaxs="i")
#Add the rectangles
rect(mdf$xleft,mdf$ybottom,mdf$xright,mdf$ytop,col=mdf$colour)
产生
