推 bboybighead2: group_by + arrange + slice 07/08 00:51
→ a78998042a: key_type_num = length(unique(your_data$KEY)) 07/08 01:41
→ a78998042a: use_index = cumsum(c(0, table(your_data$KEY)))+1 07/08 01:41
→ a78998042a: your_data[use_index[1:key_type_num], ] 07/08 01:41
→ a78998042a: or 07/08 01:42
→ a78998042a: result = lapply(split(your_data, your_data$KEY), 07/08 01:42
→ a78998042a: function(x)head(x, 1)) 07/08 01:42
→ a78998042a: do.call(rbind, result) 07/08 01:42
→ a78998042a: or your_data[!duplicated(your_data$KEY), ] 07/08 01:48
→ andrew43: data.frame用split+do.call,data.table直接上 07/08 02:14
→ andrew43: 日期可預先處理並排序會比較穩當。 07/08 02:16