在绘制曲线图而不是散点图时遇到问题答案

【问题标题】：Having problems graphing a plotly line chart instead of scatter在绘制曲线图而不是散点图时遇到问题
【发布时间】：2018-09-22 21:16:37
【问题描述】：

我创建了一个闪亮的应用程序，它有一个下拉菜单来选择项目。当前代码如下所示：

#Import libraries
library(shiny)
library(plotly)
library(tidyr)

# Define UI
ui <- bootstrapPage(

  selectInput(inputId = "n_breaks",
              label = "Select Item:",
              choices = c("item1", "item2", "item3"),
              selected = "Item1"),
 plotlyOutput(outputId = "main_plot", height = "600px")
 )

# Define server logic
server <- function(input, output) {

#Import data
df = read.csv("data/Items.csv")
#Flip data around
df2 <- df %>% 
    gather(variable, value, -(time:flex_string_2)) %>% 
    unite(temp, flex_string_2, variable) %>% 
    group_by(temp) %>% 
    mutate(id=1:n()) %>% 
    spread(temp, value) 
#Remove the id column
df2 <- subset(df2, select = -c(id))
#Remove "_extra_stuff_on_end" from titles
names(df2) = gsub(pattern = "_extra_stuff_on_end*", replacement = "", x = 
names(df2)) 
#Convert to dataframe
df3 <- as.data.frame(df2)
#Convert factor to datetime
df3$time <- as.character.POSIXt(df3$time, format = "%Y-%m-%d %H:%M:%S")  

output$main_plot <- renderPlotly({

plot_ly(df3, x = ~time, 
        y = df3[, input$n_breaks],
        type = 'scatter',
        mode = 'lines',
        color = df3[, input$n_breaks]) %>% 
  layout(xaxis = list(type = "category"))

 })   
}
# Run the application 
shinyApp(ui = ui, server = server)

数据框看起来像这样 4 列和 26949 行：

df
      time                      item1    item2    item3
1     2018-04-09 00:00:06        615       NA       NA
2     2018-04-09 00:00:08         NA      465       NA
3     2018-04-09 00:00:08         NA       NA       NA
4     2018-04-09 00:00:10         NA       NA      422
5     2018-04-09 00:00:13         NA       NA       NA
6     2018-04-09 00:00:21        522       NA      385
7     2018-04-09 00:00:25         NA       NA       NA
....  ....                       ....     ....     ...
26949 2018-04-09 23:59:59        323       NA      200

当我运行这段代码时，我得到一个散点图。我真的很想要一个折线图，但是当它运行时它是一个散点图，我收到一个警告，“警告：数字颜色变量不能（还）映射到线。当跟踪类型为“散点图”或“散点图”时。 "

如果我删除：

type = 'scatter'

我得到一个条形图。

【问题讨论】：

您能否将 Items.csv 添加（使用dput）到您的帖子中。否则，我们无法运行您的代码。

标签： r shiny plotly r-plotly

【解决方案1】：

我决定使用保留折线图的 if else 语句：

.... 
#Convert to dataframe
df3 <- as.data.frame(df2)
#Convert factor to datetime
df3$time = strptime(df3$time, '%Y-%m-%d %H:%M:%S')


output$main_plot <- renderPlotly({

  if (input$n_breaks == "item1") {
    #Create variable X getting rid of NA values
    x <- df3$time[!is.na(df3$item1)]
    #Convert date to POSIXct for plotly
    x = as.POSIXct(x,format="%Y-%m/%d T %H:%M:%S", tz ="UTC")
    #Create variable Y getting rid of NA values
    y <- df3$item1[!is.na(df3$item1)]
    #Plotly plot
    plot_ly(x = x, y = y, type = 'scatter', mode = 'lines') 
}
  else if (input$n_breaks == "item2") {
    #Create variable X getting rid of NA values
    x <- df3$time[!is.na(df3$item2)]
    #Convert date to POSIXct for plotly
    x = as.POSIXct(x,format="%Y-%m/%d T %H:%M:%S", tz ="UTC")
    #Create variable Y getting rid of NA values
    y <- df3$item2[!is.na(df3$item2)]
    #Plotly plot
    plot_ly(x = x, y = y, type = 'scatter', mode = 'lines')  
}
  else if (input$n_breaks == "item3") {
    #Create variable X getting rid of NA values
    x <- df3$time[!is.na(df3$item3)]
    #Convert date to POSIXct for plotly
    x = as.POSIXct(x,format="%Y-%m/%d T %H:%M:%S", tz ="UTC")
    #Create variable Y getting rid of NA values
    y <- df3$item3[!is.na(df3$item3)]
    #Plotly plot
    plot_ly(x = x, y = y, type = 'scatter', mode = 'lines')  
  }

  })   
}
# Run the application 
shinyApp(ui = ui, server = server)

【讨论】：