使用 renderPlot() 删除 R Shiny ggplot 中 geom_sf() 对象周围的白边距

Question

我注意到当背景为非白色时，在 Shiny 的 UI 中，renderPlot() 中显示的 sf::geom_sf() 对象周围出现了意想不到的白框。

对于 Shiny 中的其他 geom_ 对象，似乎不会出现此问题（但是...请参阅帖子末尾）。

理想情况下，我想弄清楚如何让ggplot2 对象以闪亮的方式显示，以便它们与背景颜色相匹配。

这是link to a short GIF on twitter showing the discrepancy I noticed between regular ggplot2() objects and geom_sf() objects on my data。

下面的代码似乎可以工作：

library(shiny)
library(shinyWidgets)
library(ggplot2)


# Define UI for application that draws a histogram
ui <- fluidPage(#setBackgroundColor("#E5C595"),
        # Application title
        titlePanel("Old Faithful Geyser Data"),

        # Sidebar with a slider input for number of bins 
        sidebarLayout(
                sidebarPanel(
                        sliderInput("bins",
                                    "Number of bins:",
                                    min = 1,
                                    max = 50,
                                    value = 30)
                ),

                # Show a plot of the generated distribution
                mainPanel(
                        plotOutput("distPlot")
                )
        )
)

# Define server logic required to draw a histogram
server <- function(input, output) {

        output$distPlot <- renderPlot({
                # generate bins based on input$bins from ui.R
                data    <- as.data.frame(faithful[, 2])
                colnames(data) <- "value"
                bins <- seq(min(data), max(data), length.out = input$bins + 1)

                ggplot(data, aes(x=value)) +
                        geom_histogram() +
                        theme(
                                axis.line = element_blank(),
                                axis.text.x = element_blank(),
                                axis.text.y = element_blank(),
                                axis.ticks = element_blank(),
                                axis.title.x = element_blank(),
                                axis.title.y = element_blank(),
                                panel.grid.major = element_blank(),
                                panel.grid.minor = element_blank(),
                                plot.background = element_rect("#E5C595", color = NA),
                                panel.background = element_rect("#E5C595", color = NA),
                                legend.background = element_rect("#E5C595", color = NA),
                                legend.box.background = element_rect("#E5C595", color = NA),
                                #panel.border = element_rect("transparent", color = NA)
                        )
        })
}

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

我将使用r-spatial.com 中的一个简单示例来说明geom_sf() 对象的问题。

library(shiny)
library(shinyWidgets)
library(ggplot2)
library(sf)
library(rnaturalearth)
library(rnaturalearthdata)
library(rgeos)

world <- ne_countries(scale = "medium", returnclass = "sf")
class(world)

# Define UI for application that draws a histogram
ui <- fluidPage(#setBackgroundColor("#E5C595"), # use shinywidgets to set background color
        includeCSS("style.css"),
        # Application title
        titlePanel("Old Faithful Geyser Data"),

        # Sidebar with a slider input for number of bins 
        sidebarLayout(
                sidebarPanel(
                        sliderInput("bins",
                                    "Number of bins:",
                                    min = 1,
                                    max = 50,
                                    value = 30)
                ),

                # Show a plot of the generated distribution
                mainPanel(
                        plotOutput("distPlot")
                )
        )
)

# Define server logic required to draw a histogram
server <- function(input, output) {

        output$distPlot <- renderPlot({
                # generate bins based on input$bins from ui.R
                data    <- as.data.frame(faithful[, 2])
                colnames(data) <- "value"
                bins <- seq(min(data), max(data), length.out = input$bins + 1)

                ggplot(data = world) +
                        geom_sf() +
                        theme(
                                axis.line = element_blank(),
                                axis.text.x = element_blank(),
                                axis.text.y = element_blank(),
                                axis.ticks = element_blank(),
                                axis.title.x = element_blank(),
                                axis.title.y = element_blank(),
                                panel.grid.major = element_blank(),
                                panel.grid.minor = element_blank(),
                                plot.background = element_rect("#E5C595", color = NA),
                                panel.background = element_rect("#E5C595", color = NA),
                                legend.background = element_rect("#E5C595", color = NA),
                                legend.box.background = element_rect("#E5C595", color = NA),
                                #panel.border = element_rect("transparent", color = NA)
                        )
        })
}

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

请注意，为了简单起见，我使用了library(shinyWidgets)。如果您在 .css 文件中设置以下内容，则会出现同样的问题：

身体{ 背景颜色：#E5C595； }

另一个奇怪的事情是，似乎可以工作的例子仍然有一个你可以看到的白线伪影......

Answer 1

在您的renderPlot 中，您可以添加参数bg 来设置背景颜色。为避免在调整大小时出现问题 (Check this question)，您还应该添加参数 execOnResize=TRUE。

server <- function(input, output) {
  output$distPlot <- renderPlot({
    # generate bins based on input$bins from ui.R
    data    <- as.data.frame(faithful[, 2])
    colnames(data) <- "value"
    bins <- seq(min(data), max(data), length.out = input$bins + 1)

    ggplot(data = world) +
      geom_sf() +
      theme(
        axis.line = element_blank(),
        axis.text.x = element_blank(),
        axis.text.y = element_blank(),
        axis.ticks = element_blank(),
        axis.title.x = element_blank(),
        axis.title.y = element_blank(),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        panel.border = element_blank(),
        plot.background = element_blank(),
        panel.background = element_blank(),
      )
  },  bg="#E5C595", execOnResize=T)
}

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