本文介绍了(更新)基于两列将索引列添加到data.frame的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

示例data.frame:

Example data.frame:

df = read.table(text = 'colA colB
                2 7
                2 7
                2 7
                2 7
                1 7
                1 7
                1 7
                89 5
                89 5
                89 5
                88 5
                88 5
                70 5
                70 5
                70 5
                69 5
                69 5
                44 4
                44 4
                44 4
                43 4
                42 4
                42 4
                41 4
                41 4
                120 1
                100 1', header = TRUE)

我需要根据 colA 和 colB 其中 colB 显示到的确切行数组,但它可以重复。 colB 根据 colA colA -1 对行进行分组。

I need to add an index col based on colA and colB where colB shows the exact number of rows to group but it can be duplicated. colB groups rows based on colA and colA -1.

预期输出:

 colA colB index_col
    2 7       1
    2 7       1
    2 7       1
    2 7       1
    1 7       1
    1 7       1
    1 7       1
    89 5      2
    89 5      2
    89 5      2
    88 5      2
    88 5      2
    70 5      3
    70 5      3
    70 5      3
    69 5      3
    69 5      3
    44 4      4
    44 4      4 
    44 4      4
    43 4      4
    42 4      5
    42 4      5
    41 4      5
    41 4      5
   120 1      6
   100 1      7






更新


UPDATE

如何调整适用于以上 df 出于同样的目的,但通过查看基于 colA分组的 colB colA -1 colA -2 ? ie(而不是考虑3天的2天)

How can I adapt the code that works for the above df for the same purpose but by looking at colB values grouped based on colA, colA -1 and colA -2? i.e. (instead of 2 days considering 3 days)

new_df = read.table(text = 'colA colB
        3 10
        3 10
        3 10      
        2 10
        2 10
        2 10
        2 10
        1 10
        1 10
        1 10
        90 7
        90 7
        89 7
        89 7
        89 7
        88 7
        88 7
        71 7
        71 7
        70 7
        70 7
        70 7
        69 7
        69 7
        44 5
        44 5
        44 5
        43 5
        42 5
        41 5
        41 5
        41 5
        40 5
        40 5
       120 1
       100 1', header = TRUE)

预期输出:

     colA colB index_col
        3 10      1
        3 10      1
        3 10      1
        2 10      1
        2 10      1
        2 10      1
        2 10      1
        1 10      1
        1 10      1
        1 10      1
        90 7      2
        90 7      2
        89 7      2
        89 7      2
        89 7      2
        88 7      2
        88 7      2
        71 7      3
        71 7      3
        70 7      3
        70 7      3
        70 7      3
        69 7      3
        69 7      3
        44 5      4
        44 5      4
        44 5      4
        43 5      4
        42 5      4
        41 5      5
        41 5      5
        41 5      5
        40 5      5
        40 5      5
       120 1      6
       100 1      7

谢谢

推荐答案

我们可以使用 rleid

library(data.table)
index_col <-setDT(df)[, if(colB[1L] < .N) ((seq_len(.N)-1) %/% colB[1L])+1  
       else as.numeric(colB), rleid(colB)][, rleid(V1)]
df[, index_col := index_col]
df
#    colA colB index_col
# 1:    2    7         1
# 2:    2    7         1
# 3:    2    7         1
# 4:    2    7         1
# 5:    1    7         1
# 6:    1    7         1
# 7:    1    7         1
# 8:   70    5         2
# 9:   70    5         2
#10:   70    5         2
#11:   69    5         2
#12:   69    5         2
#13:   89    5         3
#14:   89    5         3
#15:   89    5         3
#16:   88    5         3
#17:   88    5         3
#18:  120    1         4
#19:  100    1         5






或者单行将是


Or a one-liner would be

setDT(df)[, index_col := df[, ((seq_len(.N)-1) %/% colB[1L])+1, rleid(colB)][, as.integer(interaction(.SD, drop = TRUE, lex.order = TRUE))]]



更新



根据OP帖子中的新更新

Update

Based on the new update in the OP's post

setDT(new_df)[, index_col :=  cumsum(c(TRUE, abs(diff(colA))> 1))
          ][, colB := .N , index_col]
new_df
#    colA colB index_col
# 1:    3   10         1
# 2:    3   10         1
# 3:    3   10         1
# 4:    2   10         1
# 5:    2   10         1
# 6:    2   10         1
# 7:    2   10         1
# 8:    1   10         1
# 9:    1   10         1
#10:    1   10         1
#11:   71    7         2
#12:   71    7         2
#13:   70    7         2
#14:   70    7         2
#15:   70    7         2
#16:   69    7         2
#17:   69    7         2
#18:   90    7         3
#19:   90    7         3
#20:   89    7         3
#21:   89    7         3
#22:   89    7         3
#23:   88    7         3
#24:   88    7         3
#25:   44    2         4
#26:   43    2         4
#27:  120    1         5
#28:  100    1         6

这篇关于(更新)基于两列将索引列添加到data.frame的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

10-11 22:41