我有很多具有唯一标识符的村庄(村庄)的数据,我试图通过首先按年然后按月扩展来将数据塑造成长格式。
df_input <- data.frame( village=c("A","B","C"),population = c(1000,1500,2000))
df_output <- data.frame(year= c(2001,2001,2002,2003,2003),month = c("1","2","3","1","3"),village = c("A","A","C",population = c (1000,1000,2000,2000))
我使用以下代码首先按年份扩展它:
df_panel <- df_input %>%
merge(expand.grid(year=2001:2003,key=.$key),by="code_2011")
但我收到以下错误:
Error in fix.by(by.y,y) : 'by' must specify a uniquely valid column
知道我做错了什么吗?