R语言分组后取第一行
group_by(id) %>% arrange(desc(date)) %>% #按日期降序 filter(row_number()==1) %>% ungroup
参考:https://stackoverflow.com/questions/13279582/select-the-first-row-by-group
group_by(id) %>% arrange(desc(date)) %>% #按日期降序 filter(row_number()==1) %>% ungroup
参考:https://stackoverflow.com/questions/13279582/select-the-first-row-by-group
