R shiny下载选项
R shiny下载选项
提问于 2019-05-09 19:08:27
我正在处理下载用户请求的数据的问题。我想我不能理解(我是R新手，也很出色) downloadHandler的行为。我可以毫不费力地绘制选定的文件(已经作为光栅文件BFT_PR、YFT_PR和FAI存储在R中)，但在尝试下载它时，我总是得到相同的downloadData.txt和错误:服务器问题。如果能帮上忙，我将非常感谢。
server <- function(input, output) {
output$range <- renderText({paste("Forecast from", timestart, "to", timeend)})
# Reactive value for selected dataset ----
output$model <- renderPlot({
mapInput <- reactive({
switch(input$model,
"Bluefin tuna" = BFT_PR,
"Yellowfin tuna" = YFT_PR,
"Fishing Aptitude Index"=FAI)})
palette <-colorRampPalette(c("blue", "#007FFF", "cyan",
"#7FFF7F", "yellow", "#FF7F00", "red" ))(100)
spplot(mapInput(), col.regions=palette, sp.layout= list(landmask_m, landmask_u, FZ),scales=list(draw = TRUE))
})
# Download map as geotiff ----
output$downloadData <- downloadHandler(
filename = function() {paste0(input$model, ".tif")},
content = function(file) {writeRaster(mapInput(), file)}
)
}回答 1
Stack Overflow用户
发布于 2019-05-28 06:35:02
上个月我一直在旅行，很抱歉这么晚才回复。下面是我的代码示例，其中包含一些虚拟数据
r1 <- raster(matrix(sample(1:100, 100),35,52), xmn= -97.75, xmx=-84.75, ymn=17.75, ymx=26.5)
r2 <- raster(matrix(sample(100:200, 100),35,52), xmn= -97.75, xmx=-84.75, ymn=17.75, ymx=26.5)
r3 <- raster(matrix(sample(200:300,100),35,52), xmn= -97.75, xmx=-84.75, ymn=17.75, ymx=26.5)
library(shiny)
library(raster)
library(rgdal)
library (sp)
ui <- fluidPage(
App title ----
titlePanel((p("TUNAGOM DST", style = "color:#3474A7"))),
sidebarLayout(
# Sidebar panel for inputs ----
sidebarPanel(
helpText("Weekly forecasts.
Bluefin and Yellowfin tuna catch per unit effort (fish/1000 hooks).
Fishing Aptitude Index "),
# Distribution maps: Species distribution, Fishing aptitude index. Display menu
# Input: select forecast dataset
selectInput("model", "Select Forecast:",
choices = c("r1", "r2", "r3")),
# Download data button
downloadButton("downloadData", "Download data")
),
# Main panel for displaying outputs ----
mainPanel(
# Temporal range (text output)
textOutput("range"),
# Output: maps
plotOutput("model"))
)
)
server <- function(input, output) {
output$range <- renderText({paste("Forecast from", timestart, "to", timeend)})
Reactive value for selected dataset ----
output$model <- renderPlot({
mapInput <- reactive({
switch(input$model,
"r1" = r1,
"r2" = r2,
"r3"=r3)})
palette <-colorRampPalette(c("blue", "#007FFF", "cyan",
"#7FFF7F", "yellow", "#FF7F00", "red" ))(100)
spplot(mapInput(), col.regions=palette, scales=list(draw = TRUE))
})
output$downloadData <- downloadHandler(
filename = function() {paste0(input$model, ".tif")},
content = function(file) {writeRaster(mapInput(), file, format="GTiff",
overwrite=TRUE)}
)
}
runApp(shinyApp(ui, server), launch.browser = TRUE)页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/56058055
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