Question

我正在使用plotly R包在我的shiny应用程序中显示一些大图，图表显示效果很好。但是，当我单击“下载为png”按钮时，已下载的.png已调整大小。 here is a demo of this behavior

如何指定导出的绘图的分辨率？

这是一个最小的例子，它通过在下载时剪辑了一个很长的标题来证明这个问题

app.R

library(shiny)
library(ggplot2)
library(plotly)

ui <- fluidPage(titlePanel("Plotly Download demo"),

                plotlyOutput("demoPlotly"))


server <- function(input, output) {
  output$demoPlotly <- renderPlotly({
    #make an arbritrary graph with a long title
    p <- iris %>%
      ggplot(aes(x = Petal.Length, y = Petal.Width, color = Species)) +
      geom_point() +
      labs(title = "This is a really long title to demo my problem of plotly resizing my downloaded output")
    ggplotly(p)

  })
}

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

下载的图表如下所示：

Answer 1

迈克尔，

看看plotly_IMAGE()。 [版本4.7.1]。该功能允许您指定保存图像的宽度和高度。例如800乘600。

关于您的示例，我提供了一个示例，说明如何修改布局以适应标题换行。请注意更改边距和填充。我还插入了对plotly_IMAGE的调用以提供其使用的简化示例 - 它减慢了因为它与绘图生成一致。我建议您添加一个按钮并从图像显示中分离出来。

希望这有帮助

保重吨。

先决条件 - Plotly Credentials：

要使用此示例示例，您需要注册并获取plotly api密钥。获得后，您需要将这些条目添加到~/.Renviron文件中。参考：https://plot.ly/r/getting-started/

示例.Renviron文件条目

plotly_username="xxxxx"
plotly_api_key="xxxxxx"

示例代码

library(shiny)
library(ggplot2)
library(plotly)

wrapper <- function(x, ...) {
  paste(strwrap(x, ...), collapse = "\n")
}

# Example usage wrapper(my_title, width = 20)

my_title <- "This is a really long title to demo my problem of plotly resizing my downloaded output"

ui <- fluidPage(titlePanel("Plotly Download demo"), plotlyOutput("demoPlotly"))

pal <- c("blue", "red", "green")
pal <- setNames(pal, c("virginica", "setosa", "versicolor"))

layout <- list(title = wrapper(my_title, width = 60),
               xaxis = list(title = "Petal Length"),
               yaxis = list(title = "Petal Width"),
               margin = list(l = 50, r = 50, b = 100, t = 100, pad = 4))

server <- function(input, output) {
  output$demoPlotly <- renderPlotly({
    # make an arbitrary graph with a long title
    p <- iris %>%
      plot_ly(x = ~Sepal.Length,
              y = ~Petal.Width,
              color = ~Species,
              colors = pal,
              mode = "markers",
              type = "scatter") %>%
      layout(autosize = F,
             title = layout$title,
             xaxis = layout$xaxis,
             yaxis = layout$yaxis,
             margin = layout$margin)
    p$elementId <- NULL
    # Example usage of plotly image
    plotly_IMAGE(p, 
                 width = 800, 
                 height = 600, 
                 format = "png", 
                 scale = 1, 
                 out_file = "output.png")
    p
  })
}

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

屏幕截图图像 - 屏幕截图

Plotly save - 屏幕点击

plotly_IMAGE（）将图像输出800×600

保存

在RShiny应用程序中使用时，Plotly'下载为png'调整图像大小

1 个答案: