根据用户输入过滤数据范围

Question

我有一个闪亮的应用程序，它在散点图中绘制两个变量并根据用户输入进行过滤。我正在尝试获取它，以便用户可以根据他们指定的范围过滤数据。但是，我只希望在字段已填写时应用此过滤器，如果字段为空（null），则 return 应用于所有数据。例如，如果您启动我附加的代码，我希望用户能够选中“指定数据范围”复选框，当他们在最小 x 输入框中输入 4.8 时，数据会被过滤掉，这样就没有数据点了现在考虑小于 4.8。我准备的示例代码在下面，我尝试在中间附近注释掉我正在尝试做的事情。

#Check packages to use in library
{
library('shiny') #allows for the shiny app to be used
library('ggvis') #allows for interactive ploting
}

alldata <- iris

#establish options for drop down menus
{
specieschoices <- unique(as.character(alldata$Species))
}
# UI

ui<-fluidPage(
titlePanel("Explorer"),
fluidRow(
column(4,
       wellPanel(
         h4("Apply Filters"),
         selectInput(inputId = "species", label="Select a Species:", choices = sort(specieschoices), selected="setosa", multiple = TRUE, selectize = TRUE)
       )),
column(8,
       ggvisOutput("plot1")
),
column(4,
       wellPanel(
         h4("Data Variables"),
         selectInput(inputId = "x", label="Select x-axis Variable:", choices=as.character(names(alldata[,1:4])),selected='Petal.Length', multiple = FALSE),
         selectInput(inputId = "y", label="Select y-axis Variable:", choices=as.character(names(alldata[,1:4])),selected='Petal.Width', multiple = FALSE)
       )),

column(4,
       wellPanel(
         checkboxInput(inputId = "datarange", label="Specify Data Ranges", value = FALSE),
         conditionalPanel(
           condition = "input.datarange == true",
           wellPanel(
             numericInput(inputId = "minxdata", label="Specify x axis min", value = -9999999999, step = 0.1),
             numericInput(inputId = "maxxdata", label="Specify x axis max", value = 9999999999, step = 0.1),
             numericInput(inputId = "minydata", label="Specify y axis min", value = -9999999999, step = 0.1),
             numericInput(inputId = "maxydata", label="Specify y axis max", value = 9999999999, step = 0.1)
           ))
       ))
))

#SERVER
server<-function(input,output,session)
{

#Set up reactive variables for ranges
filteredData <- reactive({

minX <- input$minxdata
maxX <- input$maxxdata
minY <- input$minydata
maxY <- input$maxydata

# Apply filters
m <- alldata %>% filter(
  `Species` %in% input$species

  ###############THIS IS THE PART THAT I NEED HELP WITH
  #This works as hardcoded with hypothetical user input of x=Petal.Length and y=Petal.Width
  ,
  Petal.Length >= minX,
  Petal.Length <= maxX,
  Petal.Width >= minY,
  Petal.Width <= maxY

  #This is does not work
  # ,
  # as.symbol(input$x) >= minX,
  # as.symbol(input$x) <= maxX,
  # as.symbol(input$y) >= minY,
  # as.symbol(input$y) <= maxY
  #####################################################

)
m <- droplevels(as.data.frame(m))
m
})

vis <- reactive({

#Plot Data with Visualization Customization
xvar <- prop("x", as.symbol(input$x))
yvar <- prop("y", as.symbol(input$y))

p1 = filteredData() %>%
  ggvis(x = xvar, y = yvar) %>%
  layer_points() %>%

  # Specifies the size of the plot
  set_options(width = 800, height = 450, duration = 0)
})

#Actually plots the data
vis %>% bind_shiny("plot1")
}

#Run the Shiny App to Display Webpage
shinyApp(ui=ui, server=server)

更新：

我认为我的做法是正确的，但是如果更改为 >= 0，最小 x 和最小 y 会过滤掉所有数据，而其他过滤器如果更改则不会执行任何操作。

  paste0("`", input$x, "`") >= minX,
  paste0("`", input$x, "`") <= maxX,
  paste0("`", input$y, "`") >= minY,
  paste0("`", input$y, "`") <= maxY

Answer 1

我发现了一个基于这个完全不相关的 post 的答案，该答案探讨了他们如何以对我有用的不同方式处理数据。 Downloading png from Shiny (R)

唯一的变化是在下面 post 编辑的 filteredData 中。

#Set up reactive variables for ranges
filteredData <- reactive({

minX <- input$minxdata
maxX <- input$maxxdata
minY <- input$minydata
maxY <- input$maxydata
a <- which(names(alldata)==input$x)
xvariable <- as.numeric(alldata[,a])
b <- which(names(alldata)==input$y)
yvariable <- as.numeric(alldata[,b])

# Apply filters
m <- alldata %>% filter(
`Species` %in% input$species,
xvariable >= minX,
xvariable <= maxX,
yvariable >= minY,
yvariable <= maxY
)
m <- droplevels(as.data.frame(m))
m
})

根据用户输入过滤数据范围

Filter Data Range based on User Input

r

shiny

ggvis