从R中的一系列列中找出最大值答案

【问题标题】：Figuring out the max value from a series of columns in R从R中的一系列列中找出最大值
【发布时间】：2022-06-22 21:58:13
【问题描述】：

对于每个观察，都有三个音量值，volume_1、volume_2 和 volume_3。有时volume_1 最大，有时volume_3 最大。虽然我觉得这段代码应该很简单，但是如何计算volume_1最大，volume_2最大，然后volume_3最大的时间的整体百分比。

这是我的一些数据

structure(list(PVC = c("29A", "2D5", "2HX", "38A", "3CN", "6021051"
), Age = c(6, 5, 6, 10, 5, 7), volume_1 = c(59.44244884, 51.69518257, 
63.17950819, 56.4269955, 64.05189184, 61.82983473), volume_2 = c(54.74897726, 
56.64778447, 51.86880673, 59.71146472, 58.96633234, 63.39471043
), volume_3 = c(58.97596791, 51.75711362, 61.36142512, 57.09629745, 
64.25164825, 63.19407463), Year = c("2003", "2002", "2003", "2008", 
"2003", "1994"), averageAB = c(57.09571305, 54.17148352, 57.52415746, 
58.06923011, 61.50911209, 62.61227258), diff_AB_C = c(-1.88025486, 
2.4143699, -3.83726766, 0.972932659999998, -2.74253616, -0.58180205
), sumAB = c(114.1914261, 108.34296704, 115.04831492, 116.13846022, 
123.01822418, 125.22454516), ratioAB_C = c(1.93623657477333, 
2.09329615703558, 1.87492899154491, 2.03408041163622, 1.91463141461122, 
1.98158681637776)), row.names = c(NA, 6L), class = "data.frame")

一如既往地感谢您的帮助！！

【问题讨论】：

查看这个答案：stackoverflow.com/questions/29577665/…
prop.table(table(max.col(df[,grep('^volume_', names(df))])))*100?

标签： r

【解决方案1】：

可能有更简单的方法，但我会使用 tidyverse

df %>% 
  rowwise() %>%
  mutate(max = case_when(max(volume_1, volume_2, volume_3) == volume_1 ~ "volume_1",
                         max(volume_1, volume_2, volume_3) == volume_2 ~ "volume_2",
                         max(volume_1, volume_2, volume_3) == volume_3 ~ "volume_3") %>% 
  ungroup() %>%
  count(max)

【讨论】：

【解决方案2】：

使用max.col() 函数很容易做到这一点：

df$highest_col <- max.col(df[,3:5])

head(df)
      PVC Age volume_1 volume_2 volume_3 Year averageAB
1     29A   6 59.44245 54.74898 58.97597 2003  57.09571
2     2D5   5 51.69518 56.64778 51.75711 2002  54.17148
3     2HX   6 63.17951 51.86881 61.36143 2003  57.52416
4     38A  10 56.42700 59.71146 57.09630 2008  58.06923
5     3CN   5 64.05189 58.96633 64.25165 2003  61.50911
6 6021051   7 61.82983 63.39471 63.19407 1994  62.61227
   diff_AB_C    sumAB ratioAB_C highest_col
1 -1.8802549 114.1914  1.936237           1
2  2.4143699 108.3430  2.093296           2
3 -3.8372677 115.0483  1.874929           1
4  0.9729327 116.1385  2.034080           2
5 -2.7425362 123.0182  1.914631           3
6 -0.5818020 125.2245  1.981587           2

然后您可以在该新列上运行 table() 以获取计数。

【讨论】：