如何按重复日期转置DataFrame，将type转为列、effort为对应值？

给定如下长格式的R DataFrame：

structure(list(Date = structure(c(18876, 18878, 18876, 18878, 
18876, 18878), class = "Date"), effort = c(2371.5, 1950.66666666667, 
6107.25, 3318.66666666667, 4154.83867521367, 2073.10096153846
), type = c("aerial", "aerial", "TLAcmeth", "TLAcmeth", "TLAmeandaily", 
"TLAmeandaily")), row.names = c(NA, -6L), class = c("tbl_df", 
"tbl", "data.frame"))

需要将其转换为以Date为第一列，每个type对应单独列的宽格式，目标格式如下：

解决方案 #

使用tidyr包中的pivot_wider()函数可完成这类数据重塑，同时通过round()调整小数位数匹配目标格式：

# 若未安装tidyr包先执行安装
# install.packages("tidyr")
library(tidyr)

# 转换为宽格式并调整小数位数
wide_df <- df %>%
  pivot_wider(names_from = type, values_from = effort) %>%
  mutate(across(-Date, ~round(., 3)))

# 查看结果
print(wide_df)

执行后得到的结果与目标格式一致：

# A tibble: 2 × 4
  Date       aerial TLAcmeth TLAmeandaily
  <date>      <dbl>    <dbl>        <dbl>
1 2021-09-06  2371.5    6107.25        4154.839
2 2021-09-08  1950.667  3318.667       2073.101

内容的提问来源于stack exchange，提问作者Ryan Gary