R语言如何在map_dfr生成的结果表格中插入Category列

你可以通过左连接匹配日期与分类的对应关系实现需求，无需改动原有拟合逻辑，修改后的完整代码如下：

library(purrr)
library(dplyr)
library(tidyverse)
library(lubridate)

df1 <- structure(
  list(date1= c("2021-06-28","2021-06-28","2021-06-28","2021-06-28"),
       date2 = c("2021-06-30","2021-06-30","2021-07-01","2021-07-01"),
       Category = c("FDE","ABC","FDE","ABC"),
       Week= c("Wednesday","Wednesday","Friday","Friday"),
       DR1 = c(4,1,6,3),
       DR01 = c(4,1,4,3), DR02= c(4,2,6,2),DR03= c(9,5,4,7),
       DR04 = c(5,4,3,2),DR05 = c(5,4,5,4),
       DR06 = c(2,4,3,2),DR07 = c(2,5,4,4),
       DR08 = c(3,4,5,4),DR09 = c(2,3,4,4)),
  class = "data.frame", row.names = c(NA, -4L))

dates <- subset(df1, date2 > date1, select = date2)$date2

map_dfr(dates, ~ {
  
  datas <- df1 %>%
    filter(date2 == ymd(.x)) %>%
    summarize(across(starts_with("DR"), sum)) %>%
    pivot_longer(everything(), names_pattern = "DR(.+)", values_to = "val") %>%
    mutate(name = as.numeric(name))
  colnames(datas)<-c("Days","Numbers")
  mod <- nls(Numbers ~ b1*Days^2+b2,start = list(b1 = 47,b2 = 0), data = datas)
  tibble(dates = .x, coef = coef(mod)[2])

  }) %>%
  mutate(dates = format(ymd(dates), "%d/%m/%Y")) %>%
  # 新增左连接逻辑匹配Category
  left_join(
    df1 %>% distinct(date2, Category) %>% 
      mutate(dates = format(ymd(date2), "%d/%m/%Y")) %>% 
      select(-date2),
    by = "dates"
  ) %>%
  # 按需求调整列顺序
  select(dates, Category, coef)

运行上述代码后即可得到你预期的包含dates、Category、coef三列的结果。

内容的提问来源于stack exchange，提问作者user16774617