shiny是一个R包，用于创建交互式web应用，首先需要安装这个包。
代码语言：javascript复制install.packages("shiny")shiny包内置了11个已经写好的应用，我们可以使用runExample命令来运行。
代码语言：javascript复制library(shiny)
runExample("01_hello")Shiny应用的结构
shiny应用一般单独存放在app.R代码文件中，如果app.R 放置于newdir/目录下面，那应用就可以用runExample("newdir")来运行。
app.R包括以下三个部分：
- ui 对象
- server函数
- 对shinyApp函数的调用 ui对象控制了页面布局以及应用的外观，server用于控制交互，shinyApp函数用于创建shiny应用。
ui对象示例：
代码语言：javascript复制library(shiny)
# Define UI for app that draws a histogram ----
ui <- fluidPage(
# App title ----
titlePanel("Hello Shiny!"),
# Sidebar layout with input and output definitions ----
sidebarLayout(
# Sidebar panel for inputs ----
sidebarPanel(
# Input: Slider for the number of bins ----
sliderInput(inputId = "bins",
label = "Number of bins:",
min = 1,
max = 50,
value = 30)
),
# Main panel for displaying outputs ----
mainPanel(
# Output: Histogram ----
plotOutput(outputId = "distPlot")
)
)
)server函数示例：
代码语言：javascript复制# Define server logic required to draw a histogram ----
server <- function(input, output) {
# Histogram of the Old Faithful Geyser Data ----
# with requested number of bins
# This expression that generates a histogram is wrapped in a call
# to renderPlot to indicate that:
#
# 1. It is "reactive" and therefore should be automatically
# re-executed when inputs (input$bins) change
# 2. Its output type is a plot
output$distPlot <- renderPlot({
x <- faithful$waiting
bins <- seq(min(x), max(x), length.out = input$bins 1)
hist(x, breaks = bins, col = "#75AADB", border = "white",
xlab = "Waiting time to next eruption (in mins)",
main = "Histogram of waiting times")
})
}整体结构
代码语言：javascript复制library(shiny)
# See above for the definitions of ui and server
ui <- ...
server <- ...
shinyApp(ui = ui, server = server)运行应用
将目录名传递给runApp即可。
代码语言：javascript复制library(shiny)
runApp("my_app")Shiny内置应用
代码语言：javascript复制runExample("01_hello") # a histogram
runExample("02_text") # tables and data frames
runExample("03_reactivity") # a reactive expression
runExample("04_mpg") # global variables
runExample("05_sliders") # slider bars
runExample("06_tabsets") # tabbed panels
runExample("07_widgets") # help text and submit buttons
runExample("08_html") # Shiny app built from HTML
runExample("09_upload") # file upload wizard
runExample("10_download") # file download wizard
runExample("11_timer") # an automated timer
