Changing values in the chart in Shiny - r

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$name is a single value. However, with multiple inputs (e.g., 46 and 92), then input$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, ]