调整Shiny代码修复选择7月1日时重复生成6月30日图表的问题

问题原因 #

你的代码在自定义函数function.test内部，将传入的日期参数dmda强制覆盖为固定值2021-06-30，导致无论前端选择什么日期，后台计算始终使用6月30日，就会出现图表重复的问题。

修复方案 #

删除function.test函数内的硬编码赋值行dmda<-"2021-06-30"，同时修正原代码中管道符缺失的笔误即可，修改后的完整可运行代码如下：

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

function.test<-function(dmda,CodeChosse = "FDE"){

  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"),
         Code = 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))

  x<-df1 %>% select(starts_with("DR0"))
  
  x<-cbind(df1, setNames(df1$DR1 - x, paste0(names(x), "_PV")))
  PV<-select(x, date2,Week, Code, DR1, ends_with("PV"))
  
  med<-PV %>%
    group_by(Code,Week) %>%
    dplyr::summarize(across(ends_with("PV"), median))
  
  SPV<-df1%>%
    inner_join(med, by = c('Code', 'Week')) %>%
    mutate(across(matches("^DR0\\d+$"), ~.x + 
                    get(paste0(cur_column(), '_PV')),
                  .names = '{col}_{col}_PV')) %>%
    select(date1:Code, DR01_DR01_PV:last_col())
  
  SPV<-data.frame(SPV)
  
  mat1 <- df1 %>%
    filter(date2 == dmda, Code == CodeChosse) %>%
    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, Code == CodeChosse) %>%
    select(-any_of(dropnames))
  
  datas<-SPV %>%
    filter(date2 == ymd(dmda)) %>%
    group_by(Code) %>%
    dplyr::summarize(across(starts_with("DR0"), sum)) %>%
    pivot_longer(cols= -Code, names_pattern = "DR0(.+)", values_to = "val") %>%
    mutate(name = readr::parse_number(name))
  colnames(datas)[-1]<-c("Days","Numbers")
  
  datas <- datas %>% 
    group_by(Code) %>% 
    slice((as.Date(dmda) - min(as.Date(df1$date1) [
      df1$Code == first(Code)])):max(Days)+1) %>%
    ungroup
  
  
  f1 <- function(dat, code_nm) {
    dat <- subset(dat,  Code == code_nm)
    
    plot(Numbers ~ Days,  xlim= c(0,45), ylim= c(0,30),
         xaxs='i',data = dat,main = paste0(dmda, "-", code_nm))
    if (var(dat$Numbers)>0){
      
      model <- nls(Numbers ~ b1*Days^2+b2,start = list(b1 = 0,b2 = 0),data = dat, algorithm = "port")
      
      new.data <- data.frame(Days = with(dat, seq(min(Days),max(Days),len = 45)))
      new.data <- rbind(0, new.data)
      lines(new.data$Days,predict(model,newdata = new.data),lwd=2)
      coef<-coef(model)[2]
      points(0, coef, col="red",pch=19,cex = 2,xpd=TRUE)
      text(.99,coef + 1,max(0, round(coef,1)), cex=1.1,pos=4,offset =1,col="black")} else {
        yz <- unique(dat$Numbers)
        lines(c(0,dat$Days), c(yz, dat$Numbers), lwd = 2)
        points(0, yz, col = "red", pch = 19, cex = 2, xpd = TRUE)
        text(.1,yz+ .5, round(yz,1), cex=1.1,pos=4,offset =1,col="black")
      }
    
  }
  
  Plot1<- f1(datas, CodeChosse)
  
  
  return(list(
    "Plot1" = Plot1, 
    date2 = df1$date2,
    data = df1
  ))
}

ui <- fluidPage(
  shiny::navbarPage(theme = shinytheme("flatly"), collapsible = TRUE,
                          br(),
                          
                          tabPanel("",
                                   sidebarLayout(
                                     sidebarPanel(
                                       
                                       uiOutput("date"),
                                       textInput("Week", label = h4("Week"), value = ""),
                                       uiOutput("mycode"),
                                       br(),
                                       
                                       
                                     ),
                                     
                                     mainPanel(
                                       tabsetPanel(
                                         tabPanel("", plotOutput("graph",width = "100%", height = "600") 
                                         )
                                       ),
                                     ))
                          )))


server <- function(input, output,session) {
  
  data <- reactive(function.test("2021-06-01"))
  
  output$date <- renderUI({
    all_dates <- seq(as.Date('2021-01-01'), as.Date('2021-01-15'), by = "day")
    disabled <- as.Date(setdiff(all_dates, as.Date(data()$date2)), origin = "1970-01-01")
    dateInput(input = "date2", 
              label = h4("Data"),
              min = min(data()$date2),
              max = max(data()$date2),
              value = min(data()$date2),
              format = "dd-mm-yyyy",
              datesdisabled = disabled)
    
  })
  
  output$mycode <- renderUI({
    req(input$date2)
    df1 <- data()$data
    df2 <- df1[as.Date(df1$date2) %in% input$date2,]
    selectInput("code", label = h4("Code"),choices=unique(df2$Code))
  })
  
  output$graph <- renderPlot({
    req(input$date2,input$code)
    function.test(input$date2,as.character(input$code))[["Plot1"]]
    
  })
  
  observeEvent(input$date2, {
    updateTextInput(session, 'Week', value = weekdays(input$date2))
  })

}

shinyApp(ui = ui, server = server)

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