数据框df_biodiv含有Year、CropName、Area和FirstYear利用dplyr新建一个数据框diversity包含yeartotalareatotalvaritynewvarityyear等于df_biodiv的Year去重totalarea等于按Year分组后的总Areatotalvarity等于按Year分组后的总CropName数CropName有大量相同的去重不考虑相同
diversity <- df_biodiv %>% group_by(Year) %>% summarise(totalarea = sum(Area), totalvarity = n_distinct(CropName), newvarity = n_distinct(CropName[Year - FirstYear <=3]))
按照题目要求重新排序列
diversity <- diversity[, c("Year", "totalarea", "totalvarity", "newvarity")]
原文地址: http://www.cveoy.top/t/topic/dwqQ 著作权归作者所有。请勿转载和采集!