r - 在 Shiny R 中选择输入

Question

无法获取select input的值，需要生成词云，但是词云的内容会根据选择的option而定。

应用程序正在无限加载。请帮助我。

UI.R

fluidPage(
# Application title
titlePanel("Word Cloud"),

sidebarLayout(
# Sidebar with a slider and selection inputs
sidebarPanel(
  selectInput("selection", "Choose a book:",
              choices = c(coletor1,coletor2),
        selected = coletor1),
  actionButton("update", "Change"),
  hr(),
  sliderInput("freq",
              "Minimum Frequency:",
              min = 1,  max = 1000, value = 1),
  sliderInput("max",
              "Maximum Number of Words:",
              min = 1,  max = 100,  value = 100)
),

# Show Word Cloud
mainPanel(
 tabsetPanel(type = "tabs", 
     tabPanel("Plot", plotOutput("plot"))

)

) ) )

服务器.R

function(input, output, session) {

# Define a reactive expression for the document term matrix
terms <- reactive({
# Change when the "update" button is pressed...
input$update
# ...but not for anything else
isolate({
  withProgress({
    setProgress(message = "Processing corpus...")
    getTermMatrix(input$selection)
  })
})
})

# Make the wordcloud drawing predictable during a session
wordcloud_rep <- repeatable(wordcloud)

output$plot <- renderPlot({
v <- terms()
wordcloud_rep(names(v), v, scale=c(4,0.5),
              min.freq = input$freq, max.words=input$max,
              colors=brewer.pal(8, "Dark2"))
})
}

全局.R

library(tm)
library(wordcloud)
library(memoise)

library(RPostgreSQL)
con <- dbConnect(PostgreSQL(), user="postgres",      password="123456",dbname="postgres")
coletor1=dbGetQuery(con,"SELECT REPLACE(aux_coletprinc,' ','')          aux_coletprinc  from jabot.detacesso2 where aux_coletprinc ilike '%forz%a%'
")
coletor2=dbGetQuery(con,"SELECT REPLACE(aux_coletprinc,' ','')   aux_coletprinc  from jabot.detacesso2 where aux_coletprinc ilike '%vian%a%'
")

dbDisconnect(con)
list<-c(coletor1,coletor2) 

# Using "memoise" to automatically cache the results
getTermMatrix <- memoise(function(list) {

text <- list

myCorpus = Corpus(VectorSource(text))
myCorpus = tm_map(myCorpus, content_transformer(tolower))

myDTM = TermDocumentMatrix(myCorpus,
          control = list(minWordLength = 1))

m = as.matrix(myDTM)

sort(rowSums(m), decreasing = TRUE)
})

Answer 1

global.R 在 server.R 和 ui.R 之前运行。因此，还没有 input$selection。

您只需在 global.R 中定义 getTermMatrix 函数。无需定义 a 或要读取的 text。

您可以在 server.R 中执行这两项操作，其中 input 列表已经存在。虽然，仔细查看您的 getTermMatrix() 函数，从未使用过 book 参数。