问题
I am getting errors in my if statements with checkBoxGroupInput in my R Shiny App. Please ignore the fact that all the plots I want to output are the same - I will change this later.
Here is the code:
library(shiny)
library(leaflet)
library(DT)
library(ggplot2)
library(dplyr)
r_colors <- rgb(t(col2rgb(colors()) / 255))
names(r_colors) <- colors()
plotdata <- read.csv("C:/Users/Anatoly/Documents/Collatz/RenameLater/RenameLater/MapsAndSuch/RShinyCoral.csv")
colnames(plotdata) <- c("Year1", "RLIMona", "Year2", "RLICatalina", "Year3", "RLILaParguera1998", "Year4", "RLILAPARGUERA2004")
parguera <- read.csv("C:/Users/Anatoly/Documents/Collatz/RenameLater/RenameLater/MapsAndSuch/RShinyCoral.csv")
parguera <- select(parguera, 5:8)
colnames(parguera) <- c("Year", "1998 Expedition", "Year", "2004 Expedition")
monaisland <- read.csv("C:/Users/Anatoly/Documents/Collatz/RenameLater/RenameLater/MapsAndSuch/RShinyCoral.csv")
monaisland <- select(monaisland, 1:2)
colnames(monaisland) <- c("Year", "Mona Island RLI")
islacatalina <- read.csv("C:/Users/Anatoly/Documents/Collatz/RenameLater/RenameLater/MapsAndSuch/RShinyCoral.csv")
islacatalina <- select(islacatalina, 3:4)
colnames(islacatalina) <- c("Year", "Isla Catalina RLI")
ui <- fluidPage(
titlePanel("NOAA Coral Luminescence Data (RLI, 5-year Running Average)"),
leafletOutput("mymap"),
p(),
fluidRow(
column(3, actionButton("laparguera", "La Parguera Data"),
actionButton("mona", "Mona Island Data"),
actionButton("isla", "Isla Catalina Data"))),
fluidRow(
column(3, offset = 5, actionButton("visualize", "Visualize Data"))),
fluidRow(
column(7, offset = 5, checkboxGroupInput("checkbox", "Add to plot",
c("La Parguera" = "La Parguera", "Mona Island" = "Mona Island", "Isla Catalina" = "Isla Catalina"))),
fluidRow(
DT::dataTableOutput('tbl'),
plotOutput("plot1")
)
)
)
server <- function(input, output, session) {
output$mymap <- renderLeaflet({
leaflet() %>%
addTiles() %>%
addMarkers(lat = 17.95, lng = - 67.05, popup = "La Parguera ") %>%
addMarkers(lat = 18.00, lng = -67.50, popup = "Mona Island") %>%
addMarkers(lat = 18.2, lng = -69.00, popup = "Isla Catalina")
})
observeEvent(input$laparguera, {
output$tbl <- DT::renderDataTable(DT::datatable(parguera, options = list(pagelength = 25)))
})
observeEvent(input$mona, {
output$tbl <- DT::renderDataTable(DT::datatable(monaisland, options = list(pagelength = 25)))
})
observeEvent(input$isla, {
output$tbl <- DT::renderDataTable(DT::datatable(islacatalina, options = list(pagelength = 25)))
})
observeEvent(input$visualize, {
output$plot1 <- renderPlot(
{
if (input$checkbox == c("Mona Island"))
{
gplot <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot)
}
else if(input$checkbox == c("La Parguera", "Mona Island"))
{
gplot2 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot2)
}
else if (input$checkbox == c("La Parguera", "Mona Island", "Isla Catalina"))
{
gplot3 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot3)
}
else if(input$checkbox == c("Mona Island", "Isla Catalina"))
{
gplot4 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot4)
}
else if(input$checkbox == c("La Parguera", "Isla Catalina"))
{
gplot5 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot5)
}
else if(input$checkbox == c("Isla Catalina"))
{
gplot6 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot6)
}
else if(input$checkbox == c("La Parguera"))
{
gplot7 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot7)
}
else if(is.null(input$checkbox))
{
print("Check some damn boxes")
}
})
})
}
shinyApp(ui, server)
I think the problem is, I don't really know what type of input I get from the checkbox. I assumed it was a character vector, but I'm not sure, and the documentation wasn't very helpful (at least for me).
Thanks.
回答1:
Please note that I normally prefer to post some working code, but this time I couldn't because I do not have access to your data: my apologies.
Some consideration:
- In
checkboxGroupInputyou just need a plain character vector, i.e. you don't need to name columns etc.- The resulting
input$checkboxis another character vector checkboxGroupInputis designed to allow more than one input at a time, so the output can be a vector with more than one entry.- (minor) Rather than a cascade of
ifI normally prefer to use switch (edited: but it works only for 1 element comparisons), as it makes the code more readable (but it is personal taste).
- The resulting
In your case, to decrease the risk of errors (often due to a reactive calling the code more than once), in output$plot1 you could use
cols <- isolate(input$checkbox)
Also, rather than the existing code for output$plot1, you could eliminate an observeEvent in this way:
# snippet - not tested
#
# observeEvent(input$visualize, { # this is redundant
output$plot1 <- renderPlot(
if(is.null(input$visualize)) return() # this is all you need to make output$plot1 reactive to input$visualize
cols <- isolate(input$checkbox)
if (cols == c("Mona Island"))
{
The proliferation of nested reactive elements is never a good thing in shiny (among other things it causes unnecessarily the code to run repeatedly, burning CPU cycles).
If useful, I recently posted on SO a code example with checkboxGroupInput. See it here
If you still get errors I would suggest to post the links to allow me or others to get your data and post back a working example.
Working Example and "new comments"
library(shiny)
library(leaflet)
library(DT)
library(ggplot2)
library(dplyr)
r_colors <- rgb(t(col2rgb(colors()) / 255))
names(r_colors) <- colors()
plotdata <- read.csv("RShinyCoral.csv")
colnames(plotdata) <- c("Year1", "RLIMona", "Year2", "RLICatalina", "Year3", "RLILaParguera1998", "Year4", "RLILAPARGUERA2004")
parguera <- read.csv("RShinyCoral.csv")
parguera <- select(parguera, 5:8)
colnames(parguera) <- c("Year", "1998 Expedition", "Year", "2004 Expedition")
monaisland <- read.csv("RShinyCoral.csv")
monaisland <- select(monaisland, 1:2)
colnames(monaisland) <- c("Year", "Mona Island RLI")
islacatalina <- read.csv("RShinyCoral.csv")
islacatalina <- select(islacatalina, 3:4)
colnames(islacatalina) <- c("Year", "Isla Catalina RLI")
ui <- fluidPage(
titlePanel("NOAA Coral Luminescence Data (RLI, 5-year Running Average)"),
leafletOutput("mymap"),
p(),
fluidRow(
column(3, actionButton("laparguera", "La Parguera Data"),
actionButton("mona", "Mona Island Data"),
actionButton("isla", "Isla Catalina Data")),
column(9,
actionButton("visualize", "Add to Plot"),
checkboxGroupInput("checkbox", label = NULL,
c("La Parguera", "Mona Island", "Isla Catalina"))
)),
fluidRow(column(6, DT::dataTableOutput('tbl')),
column(6, plotOutput("plot1"))
)
)
server <- function(input, output, session) {
output$mymap <- renderLeaflet({
leaflet() %>%
addTiles() %>%
addMarkers(lat = 17.95, lng = - 67.05, popup = "La Parguera ") %>%
addMarkers(lat = 18.00, lng = -67.50, popup = "Mona Island") %>%
addMarkers(lat = 18.2, lng = -69.00, popup = "Isla Catalina")
})
observeEvent(input$laparguera, {
output$tbl <- DT::renderDataTable(DT::datatable(parguera, options = list(pagelength = 25)))
})
observeEvent(input$mona, {
output$tbl <- DT::renderDataTable(DT::datatable(monaisland, options = list(pagelength = 25)))
})
observeEvent(input$isla, {
output$tbl <- DT::renderDataTable(DT::datatable(islacatalina, options = list(pagelength = 25)))
})
output$plot1 <- renderPlot({
if(length(input$visualize) == 0 ) return()
isolate({
if(length(input$checkbox) == 0) return()
incheckbox <- input$checkbox
}) # end isolate
if(length(incheckbox) == 1) {
switch(incheckbox,
"Mona Island"= { gplot <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot) },
"Isla Catalina"= { gplot6 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot6) },
"La Parguera"= { gplot7 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot7) }
) # end switch
} else if(length(incheckbox) == 2) {
if(all(c("La Parguera", "Mona Island") %in% incheckbox)) {
gplot2 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot2)
} else if( all(c("Mona Island", "Isla Catalina") %in% incheckbox)) {
gplot4 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot4)
} else if(all(c("La Parguera", "Isla Catalina") %in% incheckbox)) {
gplot5 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot5)
}
} else if ( all(c("La Parguera", "Mona Island", "Isla Catalina") %in% incheckbox)) {
gplot3 <- ggplot(data = plotdata) +
geom_polygon(mapping = aes(x = Year1, y = RLIMona), na.rm = TRUE) +
ylab("Candelas (5-year Running Average)" )
print(gplot3)
}
})
}
shinyApp(ui, server)
The code above works for me :)
Apart the UI changes (made to get a bit tidier UI and see what was happening), the key is the if cascade`.
Take into account:
ifonly works for one element. If you compare a vector of length >1 with another vector >1, only the first matching element of the first vector is considered.- I do not consider my code particular elegant (I do not exclude later to get some better ideas!), but it should work (please let me know if it doesn't).
Suppose you have selected 3 elements.
all(c("La Parguera", "Mona Island") %in% incheckbox)would always be true. This is why currently I split the comparisons by number of elements (but there are probably other alternatives using othersetoperators likesetdiff).Please let me know if it works for you.
来源：https://stackoverflow.com/questions/43419173/errors-in-if-statements-in-r-shiny-checkboxgroupinput