Scatterplot in Shiny Module Issue - r

Question

I have a shiny app, example shown below that should be reproducible where I am trying to show a ggplot2 scatterplot with points which can be excluded as shown in this example here. I am also using modules, which might be part of this issue here.
https://gallery.shinyapps.io/106-plot-interaction-exclude/
I keep getting this "Error in eval: object 'xaxis' not found" message. Any ideas? I put the module code up front then the rest of the code for the app.R file.
library(ggplot2)
library(scales)
library(shiny)
library(shinydashboard)
###### MODULE CODE ###############
scatter_graphUI <- function(id, tab_panel_name, height = "500px") {
ns <- NS(id)
tabPanel(tab_panel_name,
plotOutput(ns("scatter_1"), height = height, click = "plot1_click", brush =
brushOpts(id = "plot1_brush")),
actionButton(ns("exclude_toggle"), "Toggle points"),
actionButton(ns("exclude_reset"), "Reset")
)
}
scatter_graph <- function(input, output, session, scatter_data, col_select) {
scatter_data_df <- reactive({
mtcars
})
vals <- reactiveValues()
data_df <- reactive({
scatter_df <- scatter_data_df()
main_df <- scatter_df[,col_select]
vals$keeprows = rep(TRUE,nrow(main_df))
main_df
})
output$scatter_1 <- renderPlot({
graph_df <- data_df()
# Plot the kept and excluded points as two separate data sets
keep <- graph_df[ vals$keeprows,]
exclude <- graph_df[!vals$keeprows,]
final_df <- keep
title = paste(colnames(final_df)[1], "vs", colnames(final_df)[2])
line_method = "quad"
axis_text = 12
title_text = 16
split_colors = TRUE
colors = c("red","black")
# create red points for negative x axis returns if split_colors is TRUE
if (split_colors == TRUE) {
final_df[,"color"] <- ifelse(final_df[,2,drop=F]<0,colors[1],colors[2])
} else {
final_df[,"color"] <- ifelse(final_df[,2,drop=F]<0,colors[2],colors[2])
}
# create a generic graphing final_df
colnames(final_df) <- c("xaxis","yaxis","color")
# setup the graph
gg <- ggplot(final_df, aes(x = xaxis, y = yaxis)) + geom_point(color = final_df[,"color"])
gg <- gg + geom_point(data = exclude, shape = 21, fill = NA, color = "black", alpha = 0.25) +
coord_cartesian(xlim = c(1.5, 5.5), ylim = c(5,35))
if (line_method == "loess") {
gg <- gg + stat_smooth(span = 0.9)
} else if (line_method == "quad") {
gg <- gg + stat_smooth(method = "lm", formula = y ~ poly(x, 2), size = 1)
} else if (line_method == "linear") {
gg <- gg + stat_smooth(method = "lm")
} else {
}
gg <- gg + theme_bw()
gg <- gg + labs(x = colnames(final_df)[2], y = colnames(final_df)[3], title = title)
gg
})
# Toggle points that are clicked
observeEvent(input$plot1_click, {
main_df <- data_df()
res <- nearPoints(main_df, input$plot1_click, allRows = TRUE)
vals$keeprows <- xor(vals$keeprows, res$selected_)
})
# Toggle points that are brushed, when button is clicked
observeEvent(input$exclude_toggle, {
main_df <- data_df()
res <- brushedPoints(main_df, input$plot1_brush, allRows = TRUE)
vals$keeprows <- xor(vals$keeprows, res$selected_)
})
# Reset all points
observeEvent(input$exclude_reset, {
main_df <- data_df()
vals$keeprows <- rep(TRUE, nrow(main_df))
})
}
########################################
##### REST OF APP CODE ######
header <- dashboardHeader(
title = 'Test Dashboard'
)
body <- dashboardBody(
tabItems(
tabItem(tabName = "scatter_eval",
tabBox(
title = "Scatter",
selected = "Selected",
height = "600px", side = "right",
scatter_graphUI("selected_scatter", "Selected")
)
)
)
)
sidebar <- dashboardSidebar(
sidebarMenu(
menuItem("Scatter Evaluation", icon = icon("th"), tabName = "scatter_eval")
)
)
ui <- dashboardPage(skin = "blue",
header,
sidebar,
body
)
server <- function(input, output, session) {
callModule(scatter_graph, id ="selected_scatter", scatter_data = reactive(selected_scatter_data()),
col_select = c(1,2))
}
shinyApp(ui = ui, server = server)
########

Answer 1

The issue is the two lines:
gg <- ggplot(final_df, aes(x = xaxis, y = yaxis)) + geom_point(color = final_df[,"color"])
gg <- gg + geom_point(data = exclude, shape = 21, fill = NA, color = "black", alpha = 0.25) +
coord_cartesian(xlim = c(1.5, 5.5), ylim = c(5,35))
Because you have not set a new aes for the exclude object, it inherits the aes from your ggplot call. It therefore needs to find a column named xaxis and yaxis in the exclude dataset. Since you only renamed final_df, it throws this error.
A graph is displayed when you change:
colnames(final_df) <- c("xaxis","yaxis","color")
to:
colnames(final_df) <- c("xaxis","yaxis","color")
colnames(exclude) <- c("xaxis","yaxis")