在 r 中，转置列并分组

Question

在 R 中，来自以下示例 df：

df <- as.data.frame(ID= c("ACTA", "ACTZ", "APHT", "ACTA", "ACTZ", "APHT"), 
                    date = c("2011-12-21", "2011-12-20", "2011-12-20", "2011-12-21", "2011-12-20", "2011-12-20", "2011-12-20"),
                    time = c("07:07:40", "07:08:20", "07:10:09", "07:10:43", "07:11:32", "07:12:32"),
                    weight_type = c("weight 1", "weight 1", "weight 1", "weight 2","weight 2", "weight 2"),
                    combined_weights = c(73.40, 77.70, 73.10, 71.80, 69.60, 68.60))

我想重新创建一个新的 df 来：

1. 有 4 个名为“time_weight_1”、“time_weight_2”、“weight_1”和“weight_2”的新列。
2. 这 4 列中的每一行都将填充当前“time”、“weight_type”和“combined_weights”列中的数据，同时根据相同的 ID 和日期进行分组。
3. 日期和 ID 列应保留

换句话说，我希望新 df 中的每一行都呈现特定日期期间特定 ID 的数据（即两次和测量的身体测量值）。

最终结果应该是：

df_new <- as.data.frame(ID= c("ACTA", "ACTZ", "APHT"), 
                    date = c("2011-12-21", "2011-12-20", "2011-12-20"),
                    time_weight_1 = c("07:07:40", "07:08:20", "07:10:09"),
                    time_weight_2 = c("07:10:43", "07:11:32", "07:12:32"),
                    weight_1 = c(73.40, 77.70, 73.10),
                    weight_2 = c(71.80, 69.60, 68.60))

我尝试了“转置”和聚合函数。但我认为这不是正确的方向。

非常感谢！

Answer 1

可能的选择：

library(tidyverse)

df <- data.frame(
  ID = c("ACTA", "ACTZ", "APHT", "ACTA", "ACTZ", "APHT"),
  date = c("2011-12-21", "2011-12-20", "2011-12-20", "2011-12-21", "2011-12-20", "2011-12-20"),
  time = c("07:07:40", "07:08:20", "07:10:09", "07:10:43", "07:11:32", "07:12:32"),
  weight_type = c("weight 1", "weight 1", "weight 1", "weight 2", "weight 2", "weight 2"),
  combined_weights = c(73.40, 77.70, 73.10, 71.80, 69.60, 68.60)
)

df |> 
  mutate(weight_type = str_replace(weight_type, " ", "_")) |> 
  pivot_wider(names_from = "weight_type", values_from = c("time", "combined_weights")) |> 
  rename_with(\(x) str_remove(x, "combined_weights_"), starts_with("comb"))
#> # A tibble: 3 × 6
#>   ID    date       time_weight_1 time_weight_2 weight_1 weight_2
#>   <chr> <chr>      <chr>         <chr>            <dbl>    <dbl>
#> 1 ACTA  2011-12-21 07:07:40      07:10:43          73.4     71.8
#> 2 ACTZ  2011-12-20 07:08:20      07:11:32          77.7     69.6
#> 3 APHT  2011-12-20 07:10:09      07:12:32          73.1     68.6

^{创建于 2024-03-17，使用 reprex v2.1.0}