Permitir espaço no nome da variável do gráfico de dispersão R brilhante

Estou desenvolvendo um aplicativo brilhante no Rstudio. O aplicativo cria dois gráficos: uma série temporal e um gráfico de dispersão. As variáveis ​​que estão sendo plotadas são Water Temperaturee Air Temperature. O gráfico de série temporal lida com o espaço nos nomes das variáveis ​​sem problemas. No entanto, recebo um erro com os gráficos de dispersão associados aos nomes das variáveis.

O erro é:

Warning: Error in parse: <text>:1:7: unexpected symbol
1: Water Temperature
          ^

ou

Warning: Error in parse: <text>:1:5: unexpected symbol
1: Air Temperature
        ^

Suspeito que esses erros tenham algo a ver com o espaço entre Água/Ar e Temperatura. É fundamental manter o espaço em vez de substituí-lo por um sublinhado ou algum outro preenchimento de espaço. Como posso manter o espaço no nome da variável ao fazer gráficos de dispersão?

library(tidyverse)
library(shiny)
library(shinydashboard)

# Create example dataset
set.seed(123)

dat <- data.frame(
  Time = rep(seq(1,10,1), times = 2),
  Site = rep(c('A', 'B'), each = 10),
  Water_Temperature = round(rnorm(20, mean = 20, sd = 5)),
  Air_Temperature = round(rnorm(20, mean = 25, sd = 3))
)

dat <- dat %>%
  rename(`Water Temperature` = Water_Temperature,
         `Air Temperature` = Air_Temperature)

dat_long <- dat %>%
  pivot_longer(cols = c("Water Temperature","Air Temperature"),
               names_to = 'Variable',
               values_to = 'Value') %>%
  arrange(Site, Time)

# Define user interface for time series and scatterplot
ui.R <- dashboardPage(
  dashboardHeader(title = "Example", titleWidth = 350),
  dashboardSidebar(
    tags$head(
      tags$style(
        HTML("
          .sidebar-footer {
            text-align: center;
          }
          .sidebar-logo {
            display: flex;
            align-items: center;
            justify-content: center;
          }
          .sidebar-menu a span {
            font-size: 24px;
          }
        ")
      )
    ),
    sidebarMenu(
      menuItem("Time Series", tabName = "time_series", icon = icon("chart-line")),
      menuItem("Scatterplot", tabName = "scatter_plot", icon = icon("chart-line"))
    )
  ),
  dashboardBody(
    tabItems(
      tabItem(
        tabName = "time_series",
        fluidRow(
          box(
            title = "Time Series",
            status = "primary",
            solidHeader = TRUE,
            width = 2,
            selectInput("siteInput", "Select Site", choices = unique(dat_long$Site)),
            selectInput("variableInput", "Select Variable", choices = unique(dat_long$Variable))
          ),
          box(
            title = "Plot",
            status = "primary",
            solidHeader = TRUE,
            width = 10,
            plotOutput("timeSeriesPlot", height = "700px")
          )
        )
      ),
      tabItem(
        tabName = "scatter_plot",
        fluidRow(
          box(
            title = "Scatterplot",
            status = "primary",
            solidHeader = TRUE,
            width = 2,
            selectInput("siteInput2", "Select Site", choices = unique(dat_long$Site)),
            selectInput("xAxisInput", "Select X-axis Variable:", choices = unique(dat_long$Variable)),
            selectInput("yAxisInput", "Select Y-axis Variable:", choices = unique(dat_long$Variable))
          ),
          box(
            title = "Plot",
            status = "primary",
            solidHeader = TRUE,
            width = 10,
            plotOutput("scatterPlot", height = "700px")
          )
        )
      ),
      tabItem(
        tabName = "site_info",
        fluidPage(
          fluidRow(
            selectInput("siteInput3", "Select Site", choices = unique(dat_long$Site)),
            column(4, dataTableOutput('table'))
          )
        )
      )
    )
  )
)

# Define server
server.R <- function(input, output) {
  output$timeSeriesPlot <- renderPlot({
    filteredData <- dat_long %>%
      filter(Site == input$siteInput, Variable == input$variableInput)
    
    variableName <- unique(filteredData$Variable)
    yLabel <- ifelse(variableName == "Water Temperature", expression(Water~Temperature~(degree*C)),
                     ifelse(variableName == "Air Temperature", expression(Air~Temperature~(degree*C))))
    
    ggplot(filteredData, aes(x = Time, y = Value)) +
      geom_line() +
      geom_point() +
      scale_x_continuous(breaks = seq(1,10,1)) +
      labs(x = "", y = yLabel,
           title = paste('Site:', input$siteInput)) +
      theme_bw()
  })
  
  output$scatterPlot <- renderPlot({
    filteredData2 <- dat_long %>%
      filter(Site == input$siteInput2)
    
    # Create a reactive label to display the units for the selected variable on the x and y axes
    xLabel <- reactive({
      switch(input$xAxisInput[1],
             `Air Temperature` = expression(Air~Temperature~(degree*C)),
             `Water Temperature` = expression(Water~Temperature~(degree*C)))
    })
    
    yLabel <- reactive({
      switch(input$yAxisInput[1],
             `Air Temperature` = expression(Air~Temperature~(degree*C)),
             `Water Temperature` = expression(Water~Temperature~(degree*C)))
    })
    
    ggplot(filteredData2, aes_string(x = input$xAxisInput, y = input$yAxisInput)) +
      geom_point() +
      labs(x = xLabel(), y = yLabel(),
           title = paste('Site:', input$siteInput2)) +
      theme_bw()
  })
}

# Run the application
shinyApp(ui = ui.R, server = server.R)

O gráfico de série temporal funciona O gráfico de dispersão não funciona