R:ggplot彩色条形图通过符号?绿色=阳性，红色=阴性

Question

我想调整我的图表，使零以下的回报为红色，正数为绿色。我在我一直在摆弄的两行代码旁边加了一条评论(问题出在最后一行代码中。其他一切都很好。

library(tidyverse)
library(tidyquant)
library(shiny)
#Stock assignments
stock_1<-'AMZN'
stock_2<-'CMG'
stock_3<-'TSS'  
stock_4<-'FB'
stock_5<-'T'
#Creating Input Boxes for Stocks and Weights of the Portfolio
ui <- fluidPage(
titlePanel('Portfolio Daily Returns'),
sidebarLayout(
sidebarPanel(
fluidRow(
column(6,textInput("S1",h3('Input Stock 1'),stock_1)),
column(6,numericInput("w1",h3("Input Weight 1"),.25))
),
fluidRow(
column(6,textInput("S2",h3('Input Stock 2'),stock_2)),
column(6,numericInput("w2",h3("Input Weight 2"),.25))
),
fluidRow(
column(6,textInput("S3",h3('Input Stock 3'),stock_3)),
column(6,numericInput("w3",h3("Input Weight 3"),.2))
),
fluidRow(
column(6,textInput("S4",h3('Input Stock 4'),stock_4)),
column(6,numericInput("w4",h3("Input Weight 4"),.2))
),
fluidRow(
column(6,textInput("S5",h3('Input Stock 5'),stock_5)),
column(6,numericInput("w5",h3("Input Weight 5"),.1))
),
dateRangeInput("D",h3("Input Start and End Dates"),
'2019-09-01',Sys.Date())
),
mainPanel(plotOutput("plot"))
)
)
server <- function(input,output){
dataInput <- reactive({
tq_get(c(input$S1,input$S2,input$S3,input$S4,input$S5),from=input$D[1],to=input$D[2])%>%
group_by(symbol)%>%
tq_transmute(select=volume,mutate_fun = periodReturn,period='daily',
col_rename = 'Daily_Vol')%>%
tq_portfolio(assets_col=symbol,returns_col = Daily_Vol,weights=c(
input$w1,input$w2,input$w3,input$w4,input$w5),col_rename = 'Port_Vol')
})
dataInput[["sign"]] = ifelse(dataInput[["value"]] >= 0, "positive", "negative") #Problem
output$plot <- renderPlot({
ggplot(dataInput(),aes(x=date,y=Port_Vol))+geom_col()+
scale_fill_manual(values = c("positive"="green","negative"=red)) #Problem 2
})
}
shinyApp(ui=ui,server=server)```

Answer 1

问题1：dataInput是一个反应对象。您应该始终使用dataInput((调用它，并且不能更改它。要么在绘图时对它进行变异，要么在返回之前简单地添加到data.frame中。所以我在dataInput调用中添加了正/负

问题2：你需要引用"红色"。此外，您还需要在aes 中指定fill=sign

下面我已经编辑了你的服务器功能，它应该可以工作，有一些关于NA的警告消息，而且我不太熟悉动物园的功能，所以我让你来整理

server <- function(input,output){
dataInput <- reactive({
dat <- tq_get(c(input$S1,input$S2,input$S3,input$S4,input$S5),from=input$D[1],to=input$D[2])%>%
group_by(symbol)%>%
tq_transmute(select=volume,mutate_fun = periodReturn,period='daily',
col_rename = 'Daily_Vol')%>%
tq_portfolio(assets_col=symbol,returns_col = Daily_Vol,weights=c(
input$w1,input$w2,input$w3,input$w4,input$w5),col_rename = 'Port_Vol')
dat$sign = ifelse(dat$Port_Vol >= 0, "positive", "negative")
return(dat)
})
output$plot <- renderPlot({
ggplot(dataInput(),aes(x=date,y=Port_Vol,fill=sign))+geom_col()+
scale_fill_manual(values = c("positive"="green","negative"="red")) #Problem 2
})
}