调整Shiny代码使函数生成Test数据集的第二段代码正常展示运行结果

核心错误点 #

1. 函数逻辑嵌套错误：将Test数据集生成代码写在了计算单个coef值的return_coef函数内部，导致调用时递归死循环，无法正常输出结果
2. 函数返回值不符合要求：function.test当前仅返回原始数据df1，没有生成与第一段代码结构一致、带coef列的Test数据集
3. 日期格式不匹配：df1中的date2列为字符类型，未转为Date类型，无法正常用于日期范围筛选逻辑
4. 正则表达式转义错误：matches("^DR0\d+$")缺少转义符，R中需写为matches("^DR0\\d+$")才能正确匹配列名
5. 分组汇总未关闭分组：dplyr的summarize操作后未添加.groups = "drop"参数，会导致后续计算出现分组冲突警告

修复后完整代码 #

library(shiny)
library(shinythemes)
library(dplyr)
library(writexl)
library(tidyverse)
library(lubridate)

function.test<-function(){
  
  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","2021-07-02"),
         Category = c("FDE","ABC","FDE","ABC"),
         Week= c("Wednesday","Wednesday","Friday","Friday"),
         DR1 = c(4,1,6,1),
         DR01 = c(4,1,4,4), DR02= c(4,2,6,0),DR03= c(9,5,4,0),
         DR04 = c(5,4,3,5),DR05 = c(5,4,5,0),
         DR06 = c(2,4,3,5),DR07 = c(2,5,4,0),
         DR08 = c(3,4,5,0),DR09 = c(2,3,4,0)),
    class = "data.frame", row.names = c(NA, -4L))
  
  # 转换日期格式为Date类型
  df1$date1 <- ymd(df1$date1)
  df1$date2 <- ymd(df1$date2)
  
  # 定义coef计算函数，仅返回单个计算结果
  return_coef <- function(df1, dmda, CategoryChosse) {
    
    x<-df1 %>% select(starts_with("DR0"))
    
    x<-cbind(df1, setNames(df1$DR1 - x, paste0(names(x), "_PV")))
    PV<-select(x, date2,Week, Category, DR1, ends_with("PV"))
    
    med<-PV %>%
      group_by(Category,Week) %>%
      summarize(across(ends_with("PV"), median), .groups = "drop")
    
    SPV<-df1%>%
      inner_join(med, by = c('Category', 'Week')) %>%
      mutate(across(matches("^DR0\\d+$"), ~.x + 
                      get(paste0(cur_column(), '_PV')),
                    .names = '{col}_{col}_PV')) %>%
      select(date1:Category, DR01_DR01_PV:last_col())
    
    SPV<-data.frame(SPV)
    
    mat1 <- df1 %>%
      filter(date2 == dmda, Category == CategoryChosse) %>%
      select(starts_with("DR0")) %>%
      pivot_longer(cols = everything()) %>%
      arrange(desc(row_number())) %>%
      mutate(cs = cumsum(value)) %>%
      filter(cs == 0) %>%
      pull(name)
    
    (dropnames <- paste0(mat1,"_",mat1, "_PV"))
    
    SPV <- SPV %>%
      filter(date2 == dmda, Category == CategoryChosse) %>%
      select(-any_of(dropnames))
    
    datas<-SPV %>%
      filter(date2 == ymd(dmda)) %>%
      group_by(Category) %>%
      summarize(across(starts_with("DR0"), sum), .groups = "drop") %>%
      pivot_longer(cols= -Category, names_pattern = "DR0(.+)", values_to = "val") %>%
      mutate(name = readr::parse_number(name))
    colnames(datas)[-1]<-c("Days","Numbers")
    
    datas <- datas %>% 
      group_by(Category) %>% 
      slice((as.Date(dmda) - min(as.Date(df1$date1) [
        df1$Category == first(Category)])):max(Days)+1) %>%
      ungroup
    
    mod <- nls(Numbers ~ b1*Days^2+b2,start = list(b1 = 0,b2 = 0),data = datas, algorithm = "port")
    # 仅返回计算得到的coef值
    return(as.numeric(coef(mod)[2]))
  }
  
  # 批量计算所有行的coef值，生成与第一段代码结构一致的Test数据集
  Test <- cbind(df1 %>% select(date2,Category), coef = mapply(function(d, c) return_coef(df1, d, c), df1$date2, df1$Category))
  return(Test)
}

ui <- fluidPage(
  
  shiny::navbarPage(theme = shinytheme("flatly"), collapsible = TRUE,
                    br(),
                    tabPanel("",
                             sidebarLayout(
                               sidebarPanel(
                                 uiOutput('daterange'),
                                 br()
                                 
                               ),
                               mainPanel(
                                 dataTableOutput('table'),
                                 br(), br(), 
                                 downloadButton("dl", "Download")
                               ),
                             ))
  ))

server <- function(input, output,session) {
  
  data <- reactive(function.test())
  
  data_subset <- reactive({
    req(input$daterange1)
    days <- seq(input$daterange1[1], input$daterange1[2], by = 'day')
    subset(data(), date2 %in% days)
  })
  
  output$daterange <- renderUI({
    dateRangeInput("daterange1", "Period you want to see:",
                   start = min(data()$date2),
                   end   = max(data()$date2))
  })
  
  output$table <- renderDataTable({
    data_subset()
  })
  
  output$dl <- downloadHandler(
    filename = function() { "data.xlsx"},
    content = function(file) {
      writexl::write_xlsx(data_subset(), path = file)
    }
  )
}

shinyApp(ui = ui, server = server)

内容的提问来源于stack exchange，提问作者Antonio