shiny 里面地图不显示

[mexin56]

麻烦帮忙看一下
library(recharts)
library(shiny)
app = shinyApp(
ui = fluidPage(eChartOutput('myChart')),
server = function(input, output) {
mapData <- head(mapTestData_chs, 5)
chart= eMap(mapData, namevar=~stdName, datavar = ~val1 + val2)
output$myChart = renderEChart(chart) }
)

if (interactive()) runApp(app)