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I’m building a new program, but when I run it, an error pops up. The error displayed is as follows:
Error: cannot coerce type 'closure' to vector of type 'character'I have tried several workarounds, but they still do not get the desired results. If you have come across this situation and have a solution for the “cannot coerce type ‘closure’ to vector of type ‘character’” problem, pls let me know. Here is what I do:
library(shiny)
# Define UI for dataset viewer application
shinyUI(fluidPage(
# Application title
titlePanel("Shiny Text"),
# Sidebar with controls to select a dataset and specify the
# number of observations to view
sidebarLayout(
sidebarPanel(
selectInput("dataset1", "Choose a Sepal Measure:",
choices = c("Sepal Length", "Sepal Width")),
selectInput("dataset2", "Choose a Petal Measure:",
choices = c("Petal Length", "Petal Width"))
),
# Main Scatter Plot
mainPanel(
textOutput("testvar"),
plotOutput("myplot")
)
)
))library(shiny)
library(datasets)
library(ggplot2)
#Define a function to plot passed string variables in ggplot
myplotfunct = function(df, x_string, y_string) {
ggplot(df, aes_string(x = x_string, y = y_string)) + geom_point()
}
shinyServer(function(input, output) {
# Sepal Inputs
datasetInput1 <- reactive({
switch(input$dataset1,
"Sepal Length" = "Sepal.Length",
"Sepal Width" = "Sepal.Width")
})
# Petal Inputs
datasetInput2 <- reactive({
switch(input$dataset2,
"Petal Length" = "Petal.Length",
"Petal Width" = "Petal.Width")
})
#Debug print value of sting being passed
output$testvar = renderText(print(datasetInput1))
# Plot
output$myplot = renderPlot({myplotfunct(iris, datasetInput1, datasetInput2)})
})Thanks!
The cause: The problem is caused by the calls to datasetInput1 and datasetInput2 in the two last lines.
The solution: To fixx this error, you should use datasetInput1() and datasetInput2(). Otherwise, R will attempt to transform the function to a char value. It should be as follows:
Rather than interacting with the reactive element directly, the
()allows you to get the value of the reactive element.