X VarがPOSIXctのときに光沢のあるnearPointsが動作しない

Question

私はYahooから在庫データを要求するちょっとしたアプリに取り組んでいます。プロットをクリックすると、データセットのそれぞれの価格/日時の行が表示されます。しかし残念ながら、input$plot_clickは正しいx、y値を返さないようです。ここで

はMWEです：

library(shiny) 
library(htmlwidgets) 
library(ggplot2) 
library(scales) 
library(dplyr) 
library(RCurl) 
library(XML) 
library(rvest) 

server <- function(input, output, session) { 
    Sys.setlocale("LC_TIME", "C") 
    dataset <- data.frame() 
    xml.url <- "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.quote%20where%20symbol%20in%20(%22YHOO%22%2C%22AAPL%22%2C%22GOOG%22%2C%22MSFT%22)&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys" 

    YahooObs <- function(xml.url){ 
     script <- getURL(xml.url) 
     doc  <- xmlParse(script) 
     results <- doc %>% xml_nodes("results") 
     dataset <- lapply(results, FUN=function(x){xmlToDataFrame(x, stringsAsFactors = F)})[[1]] 
     dataset$LastTradePriceOnly <- as.numeric(dataset$LastTradePriceOnly) 
     created <- doc %>% xml_node("query") %>% xml_attr("created") 
     dataset$created <- as.POSIXct(strptime(created, format="%Y-%m-%dT%H:%M:%SZ", tz="UTC")+3600) 
     return(dataset) 
    } 

    output$newsplot <- renderPlot({ 
    invalidateLater(10000, session) 
    dataset <<- rbind(dataset, YahooObs(xml.url)) 
    p <- ggplot(data = dataset) 
    p <- p + layer(mapping=aes(x=created, y=LastTradePriceOnly, color= Symbol), 
       geom="point", stat="identity", position="identity") 
    limit_down <- as.POSIXct(Sys.time()-input$timeslider*60) 
    attributes(limit_down)$tzone <- input$timezone 
    limit_up <- as.POSIXct(Sys.time()) 
    attributes(limit_up)$tzone <- input$timezone 
    p <- p + scale_x_datetime(breaks = date_breaks("200 sec"), labels = date_format("%H:%M:%S"), 
          limits=c(min(dataset$created-1800), max(dataset$created))) + 
    theme(axis.text.x = element_text(angle = 90), panel.grid.major=element_blank(), panel.grid.minor=element_blank(), 
     panel.background = element_blank()) + coord_cartesian() 
    print(p) 
    }) 

    output$plot_click <- renderPrint({ 
     paste(str(input$plot_click)) 
    }) 

    output$newstable <- renderDataTable({ 
     ##Transforming the created column to numeric was a hint on stackoverflow but it didn't work out 
     #dataset$created <- as.numeric(dataset$created) 
     nearPoints(dataset, input$plot_click, xvar="created",yvar="LastTradeDatePrice", threshold = 100, maxpoints = 10, 
      addDist = TRUE) 
})} #the server 

ui_2 <- shinyUI(fluidPage(
    #header 
    titlePanel(tags$h1("Share Prices")), 
    #horizontal line 
    sidebarLayout(
     sidebarPanel(
      sliderInput("timeslider", label = "Choose Timespan in minutes", min = 1, max = 60, value = 30, step = 1), 
    width=3 
    ), 
     mainPanel(
     tabsetPanel(type="tabs", 
       tabPanel("News Plot", plotOutput("newsplot", click="plot_click"),dataTableOutput("newstable"), textOutput("plot_click")), 
       tabPanel("Settings", selectInput("timezone", label="Choose your Timezone", choices=c("UTC"))) 
) 
) 
)))# the user interface 

shinyApp(ui = ui_2, server = server) # this launches your app 

任意のアイデア？

Answer 1

print(p)は何かを操作するようです。 pのみを使用すると問題が解決され、POSIXctの値は正しく数値として表示されます。

p <- ggplot(data = dataset) 
p <- p + layer(mapping=aes(x=created, y=LastTradePriceOnly, color= Symbol), 
      geom="point", stat="identity", position="identity")limit_down <- as.POSIXct(Sys.time()-input$timeslider*60) 
attributes(limit_down)$tzone <- input$timezone 
limit_up <- as.POSIXct(Sys.time()) 
attributes(limit_up)$tzone <- input$timezone 
p <- p + scale_x_datetime(breaks = date_breaks("200 sec"), labels = date_format("%H:%M:%S"), 
         limits=c(min(dataset$created-1800), max(dataset$created))) + 
theme(axis.text.x = element_text(angle = 90), panel.grid.major=element_blank(), panel.grid.minor=element_blank(), 
    panel.background = element_blank()) + coord_cartesian() 
p 

作品です。