I am trying to create a shiny application that will allow you to download a nicely formatted PDF report, according to user-defined sub-analyses. I found this gist containing a minimal example, which works just fine. However, when I tried to add a plot, based on the 'Miles-per-gallon' example from the Rstudio gallery, I ran into some errors when I tried adapting the code.
Here is my server.R
code:
library(knitr)
library(datasets)
library(ggplot2)
mpgData <- mtcars
mpgData$am <- factor(mpgData$am, labels = c("Automatic", "Manual"))
shinyServer(function(input, output) {
formulaText <- reactive({
paste("mpg ~", input$variable)
})
# Return the formula text for printing as a caption
output$caption <- renderText({
formulaText()
})
# Generate a plot of the requested variable against mpg and only
# include outliers if requested
output$mpgPlot <- renderPlot({
boxplot(as.formula(formulaText()),
data = mpgData,
outline = input$outliers)
})
myPlot1 <- reactive({
p <- print(ggplot(mpgData, aes(mpg, input$variable)) +
geom_line())
})
myPlot2 <- reactive({
#renderPlot({
p <- print(
boxplot(as.formula(formulaText()),
data = mpgData,
outline = input$outliers)
)
})
output$report = downloadHandler(
filename = 'myreport.pdf',
content = function(file) {
out = knit2pdf('input.Rnw', clean = TRUE)
file.rename(out, file) # move pdf to file for downloading
},
contentType = 'application/pdf'
)
})
and here is my ui.r
code
library(shiny)
library(datasets)
shinyUI(fluidPage(
# Application title
titlePanel("Miles Per Gallon"),
# Sidebar with controls to select the variable to plot against mpg
# and to specify whether outliers should be included
sidebarLayout(
sidebarPanel(
textInput('firstname', 'First name', value = 'Adam'),
textInput('lastname', 'Last name', value = 'Smith'),
downloadButton('report'),
selectInput("variable", "Variable:",
c("Cylinders" = "cyl",
"Transmission" = "am",
"Gears" = "gear")),
checkboxInput("outliers", "Show outliers", FALSE)
),
# Show the caption and plot of the requested variable against mpg
mainPanel(
h3(textOutput("caption")),
plotOutput("mpgPlot")
)
)
))
while the input.Rnw
file looks like this:
\documentclass{article}
\begin{document}
<<names>>=
input$firstname
input$lastname
@
<<>>=
#output$mpgPlot ## N.B. This threw an error! Cannot call an object like this from shiny
print(myPlot1())
@
<<>>=
print(myPlot2())
@
\end{document}
I've been playing around with this for a few hours now, and I'm pretty stuck. The input$names
part works fine, but I cannot figure out how to bring in a reactive
plot. The error/warning message is 'Error: object ’input’ not found'
, so I know it is not detecting the input$variable changes being passed from the ui.R
script. Thanks for your help solving this
sessionInfo()
R version 3.1.0 (2014-04-10)
Platform: x86_64-apple-darwin13.1.0 (64-bit)
locale:
[1] en_GB.UTF-8/en_GB.UTF-8/en_GB.UTF-8/C/en_GB.UTF-8/en_GB.UTF-8
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] ggplot2_0.9.3.1.99 knitr_1.6 shiny_0.10.0
loaded via a namespace (and not attached):
[1] bitops_1.0-6 caTools_1.17 colorspace_1.2-4 digest_0.6.4 evaluate_0.5.5 formatR_0.10 grid_3.1.0 gtable_0.1.2
[9] highr_0.3 htmltools_0.2.4 httpuv_1.3.0 labeling_0.2 MASS_7.3-33 munsell_0.4.2 plyr_1.8.1 proto_0.3-10
[17] RColorBrewer_1.0-5 Rcpp_0.11.2 reshape2_1.4 RJSONIO_1.2-0.2 scales_0.2.4 stringr_0.6.2 tools_3.1.0 xtable_1.7-3
plot(as.formula(formulaText()), data = mpgData)
– Yihui Xieprint(myplot1())
withplot(as.formula(formulaText()), data = mpgData)
ininput.Rnw
. I have tried adapting this to ggplot2, by addingggPlotText <- reactive({paste('mpg,', input$variable)})
toserver.R
and thenggplot(mpgData, aes(ggPlotText())) + geom_line()
toinput.Rnw
, which seems to follow the logic offormulaText()
, but the error message produced saysError: could not find function "ggPlotText"
. Is there an equivalent toas.formula()
that I can use for theaes(x, y)
convention of ggplot2?toString
didn't work – Jonnyupdate.packages()
). – Yihui Xie