基于R语言的中国柑橘主要病虫害空间漫衍图

R源代码如下（以蚧类为例）R Code (Scale as an example)：

require(maptools) #装载舆图东西成果包 Load maptools

read.shape(“pests”) -> pestmap #读入中国柑橘病虫害的shp文件 Read the shp file of Chinese citrus pests and diseases
attributes(pestmap$att.data) #查察该shp文件的属性表 View the atrribute tables of the above shp file.

# 蚧类产生率分成三组并用差异颜色显示 The damage rates of scale insect are divided into 3 groups and showed with different colours
br1 <- c(0.015,0.035,0.055,0.074)
rm <- cut(pestmapatt.data 蚧类,breaks=br1,labels=c(1:3))
cols <- c(“gray”,”blue”,”red”)
fgs <- cols[rm]

# 出产柑橘蚧类为害率的空间漫衍图 Plot the distribution map of scale damage rate
plot.Map(pestmap,fg=fgs,ol=”black”,main=”柑橘蚧类为害率”, xlab=”经度”, ylab=”纬度”)

# 图注 Legends
legtext <- c(“0.016-0.035″,”0.035-0.055″,”0.055-0.074”)
legend(“topright”,bg=”white”, fill=cols,legend=legtext)

# 符号各省市区名称 Label the names of provinces, cities and regions
dat = read.csv(con <- textConnection(“lb,jd,wd
重 庆 市,106.3,29.6
浙 江 省,119.2,29
湖 南 省,111.3,28.1
江 西 省,115.9,28.2
湖 北 省,112,31
四 川 省,103,30.65
贵 州 省,106.5,27.1
福 建 省,117.8,26.5
广 东 省,113.2,23.5
广西壮族自治区,108.7,24.3
云 南 省,101.2,24.8
陕 西 省,108.3,34.1”))
text(datjd,dat wd,dat$lb,col=”white”)
close(con)