为什么在下面的代码示例中renderImage()
无法识别:input
library(d3heatmap)
library(shiny)
library(ggplot2)
ui <- fluidPage(
h1("A heatmap demo"),
selectInput("palette", "Palette", c("YlOrRd", "RdYlBu", "Greens", "Blues")),
checkboxInput("cluster", "Apply clustering"),
downloadButton('downloadPlot', 'Download Heatmap'),
d3heatmapOutput("heatmap")
)
server <- function(input, output, session) {
output$heatmap <- renderD3heatmap({
d3heatmap(
scale(mtcars),
colors = input$palette,
dendrogram = if (input$cluster) "both" else "none"
) })
output$downloadPlot <- renderImage(
d3heatmap(scale(mtcars), colors = input$palette, dendrogram = if (input$cluster) "both" else "none"),
env = parent.frame(),
quoted = FALSE,
deleteFile = FALSE
)
}
shinyApp(ui = ui, server = server)
这是我的错误:
Error in match.arg(dendrogram) : object 'input' not found
当我删除该dendrogram = if (input$cluster) "both" else "none"
行时,我input
再次收到以下错误:
Error in toPaletteFunc(pal) : object 'input' not found
input
找不到该对象似乎有点违反直觉,因为我已经在楼上明确定义了它: server <- function(input, output, session)
。
我已经检查了生成类似错误消息的现有 Stack Overflow 帖子(例如,R Shiny error: object input not found)。
上面的代码示例的灵感来自:https ://cran.r-project.org/web/packages/d3heatmap/d3heatmap.pdf