I'm trying to make a Shiny app which will take an uploaded CSV file and convert it into a tibble and then make a series of plots with the same X but using different columns for Y data, one per plot. I want the user to be able to use check boxes to select which plots they want to display and plot the result using plot_grid.
So far I managed to get the script to render the plots the way I want them and to draw them all on the fly from plot_grid if I name them manually. I'm having trouble including checkboxGroupInput output as an input for plot_grid, the characted vector returned cannot be used as a grob object. Here's the relevant code:
ui <- fluidPage(
titlePanel("Title"),
sidebarLayout(
sidebarPanel(
#Select which plots will be displayed
checkboxGroupInput(inputId = "whichPlot",
label = "Select data to plot",
choices = c("Temperature" = "tempChart()",
"Pressure" = "pressureChart()",
"Dissolved Oxygen" = "airsat()",
"pH" = "phChart()",
"Air flow" = "airChart()",
"Oxygen flow" = "O2Chart()"),
selected = "Temperature"),
#Select time scale
selectInput("timeScale",
"Choose time scale to plot",
choices = c("Minutes",
"Hours",
"Days"),
selected = "Minutes"),
#Apply button to make graphs
actionButton("DoIt", "Plot data"),
br(),
),
mainPanel(
plotOutput("plot"),
#the outputs below are not necessary, I just use them to see if I'm going in the right direction
textOutput("tableTitle"),
tableOutput("table"),
textOutput("selection"),
tableOutput("dataSummary")
)
)
)
server <- function(input, output) {
#A dummy tibble that I use for testing. will be replaced by Load button
dataDF <- tibble(date = c("01/01/2021","01/01/2021","01/01/2021","01/01/2021"), time = c("10:51:02","10:52:02","10:53:02","10:54:02"),
temp = c(20.000,22.000,23.000,24.000), pressure = c(50.000,50.000,50.000,50.000),
pH = c(7.000, 7.230, 7.100, 7.040), pO2 = c(100.000, 90.000, 80.000, 70.000),
airflow = c(1.000,1.000,1.000,1.000), O2flow = c(1.000,1.000,1.000,1.000), user = c("user","user","user","user"),
level = c(3,3,3,3), acid = c("00:00:00","00:00:00","00:00:00","00:00:00"), base =c("00:00:00","00:00:00","00:00:00","00:00:00"),
mins = c(0,2,3,4), hrs = c(0,60,180,360), dys = c(0,15,25,35))
output$table <- renderTable(head(dataDF))
#This changes the X axis scale and works well
colsel <- reactive({
switch(input$timeScale,
"Minutes" = 13,
"Hours" = 14,
"Days" = 15)
})
dataT <- reactive({
df <-dataDF[, 3:8]
df$runTime = pull(dataDF, colsel())
df
})
#A control table output to make sure tibble transformation worked (it works!)
output$dataSummary <- renderTable({
head(dataT())})
#Create a list of plots to be drawn from the checkboxes
plots <- reactive({
paste(input$whichPlot, sep = ",")
})
#save all the plots to individual objects to be chosen from later
airChart <- reactive({
ggplot(dataT(), aes(x = runTime, y = airflow))+
geom_line(size = 1, color = "#00B388")+
labs(x = paste("Runtime in",input$timeScale), y = "Air flow [L/min]")+
scale_x_continuous(breaks = breaks_extended(n = 10))+
ylim(0, 1)
})
tempChart <- reactive({
ggplot (dataT(), aes(runTime, temp))+
geom_line(size = 1, color = "#00B388")+
labs(x = paste("Runtime in",input$timeScale), y = expression(paste("Temperature [", degree, "C]")))+
scale_x_continuous(breaks = breaks_extended(n = 10))+
ylim(15, 45)
})
airsat <- reactive({
ggplot(dataT(), aes(runTime, pO2))+
geom_line(size = 1, color = "#00B388")+
labs(x = paste("Runtime in",input$timeScale), y = "%O2 saturation")+
scale_x_continuous(breaks = breaks_extended(n = 10))+
ylim(80, 100)
})
phChart <- reactive({
ggplot(dataT(), aes(runTime, pH))+
geom_line(size = 1, color = "#00B388")+
labs(x = paste("Runtime in",input$timeScale), y = "pH")+
scale_x_continuous(breaks = breaks_extended(n = 10))+
ylim(1,15)
})
O2Chart <- reactive({
ggplot(dataT(), aes(runTime, O2flow))+
geom_line(size = 1, color = "#00B388")+
labs(x = paste("Runtime in",input$timeScale), y = "O2 flow [L/min]")+
scale_x_continuous(breaks = breaks_extended(n = 10))+
ylim(0,10)
})
pressureChart <- reactive({
ggplot(dataT(), aes(runTime, pressure))+
geom_line(size = 1, color = "#00B388")+
labs(x = paste("Runtime in",input$timeScale), y = "Pressure [mbar]")+
scale_x_continuous(breaks = breaks_extended(n = 10))+
ylim(0,220)
})
#Plot my charts
observeEvent(input$DoIt,{
output$plot <- renderPlot({
(plot_grid(plots(), ncol = 2, labels = "auto"))
})
})
}
shinyApp(ui = ui, server = server)
When I try to use it, I get an error
Warning in as_grob.default(plot) :
Cannot convert object of class character into a grob.
Warning in grid.echo.recordedplot(dl, newpage, prefix) :
No graphics to replay
If I replace the last line with
output$plot <- renderPlot({
(plot_grid(tempChart(), airsat(), O2Chart(), pressureChart(), ncol = 2, labels = "auto"))
it works just fine. I'm not sure if there's a way to bypass the character to grob issue or if I'm making it unnecessarily too difficult. I looked at other solutions with if (which I don't fully understand) but I don't think they'll help here. It's my first contact with Shiny, so don't be too harsh please.
question from:
https://stackoverflow.com/questions/66048682/use-checkboxgroupinput-in-shiny-to-make-selectable-plots-from-one-tibble-with-pl 
