trailingOnly=TRUE时,参数索引从1开始;
当trailingOnly=TRUE时,参数索引从6开始,因为:
args[1]= "C:\\Program Files\\R\\R-3.4.4\\bin\\x64...in `[.data.frame`(df, "1") : undefined columns selected
数据筛选
# 条件语句选择列
> df[which(df$one>2),]
one...(one=c(9,8,7,6,12))
> cbind(df,df4)
Error in data.frame(..., check.names = FALSE) :
参数值意味着不同的行数: 4..., 5
虽然df_n的行数小于df,但df不是df_n行数的整数倍时,也会失败
> cbind(df,data.frame(one=c(5,2,3),two=c(12),three=c(9)))
Error...> rbind(df, data.frame(one_t=c(5),two=c(12),three=c(9),four=c(4)))
Error in rbind(deparse.level, ..