Shiny R中的selectinput

Question

我无法获得选择输入的值，我需要生成一个词云，但是云的内容将取决于所选选项。

该应用程序正在无限加载。 请帮帮我。

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"))

)

）））

Server.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"))
})
}

Global.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，尚无input$selection 。

您只需要在global.R 定义 getTermMatrix函数global.R 。 有没有需要定义a也没有text是要被读取。

您可以在input列表已存在的server.R进行这两个操作。 总体来说，请更好地研究getTermMatrix()函数，从不使用book参数。