在 Shiny 中更改图表中的值

Question

I have a simple shiny application and I don't know why the values on the chart change when I choose multiple items from a list. Below my example and images with bad charts.

ui

library(shiny)
library(plotly)

shinyUI(fluidPage(

    titlePanel("App test"),

    sidebarPanel(
        h3(" "),
        selectizeInput("name",
                       label = "Code",
                       choices = unique(data$Product),
                       multiple = T,
                       options = list(maxItems = 5, placeholder = 'Select a code'),
                       selected = "46")
        ),

    mainPanel(
        plotOutput("trendPlot")
    )
)
)

server

shinyServer(function(input, output, session) {

    output$trendPlot <- renderPlot({

            df_trend <- data[data$Product == input$name, ]

            ggplot(df_trend) +
                geom_line(aes(x = Month, y = Value, group = Product, colour = Product)) +
                theme(legend.position = "bottom")              

    })
})

Head my data:

> head(data)
# A tibble: 6 x 3
  Product Month Value
  <chr>   <chr> <dbl>
1 46      Jan     188
2 46      Feb     277
3 46      Mar     317
4 46      Apr     367
5 46      May     329
6 46      Jun     318

Answer 1

The data set above only includes '46' for Product so cannot reproduce. However, I suspect the problem is how you are filtering data, allowing for multiple inputs with selectizeInput .

Right now you filter data:

df_trend <- data[data$Product == input$name, ]

Which is fine if input$name is a single value. However, with multiple inputs (eg, 46 and 92), then input$name contains those two values, and you need a different kind of comparison.

To subset your data based on multi-value matching (like matching a vector), try instead:

df_trend <- data[data$Product %in% input$name, ]