server.R

# This is the server logic for a Shiny web application.
# You can find out more about building applications with Shiny here:
# 
# http://www.rstudio.com/shiny/
#
source("power.R")
library(shiny)

shinyServer(function(input, output) {
	output$r2output <- renderText({
		r2tof2(r2=input$r2value)
	})
   
	output$pwrPlot <- renderPlot({
     
    # generate and plot an rnorm distribution with the requested
    # number of observations
	if(input$power == 0){
		power <- NULL
	}
	else{
		power <- input$power
	}
	if(input$dfs.plot == 0){
		dfs.plot <- NULL
	}
	else{
		dfs.plot <- input$dfs.plot
	}
  	pwrFrame <- createPwrFrame(effectSizes=input$effectSize,
  				   dfs=5:input$dfs,
  				   dfNumerator=input$dfNumerator,
  				   sig.level=input$sigLevel,
  				   alternative=input$alternative,
  				   test=input$test,
  				   type=input$type,
  				   standard=input$standard)
  	print(plotPower(pwrFrame,guides=input$guides,power=power,df=dfs.plot))
	})
    
	output$downloadButton <- downloadHandler(
		filename = function(){
			paste0("powerPlot.",as.character(input$plotFormat))
		},
		content = function(file){
			if(input$power == 0){
				power <- NULL
			}
			else{
				power <- input$power
			}
			if(input$dfs.plot == 0){
				dfs.plot <- NULL
			}
			else{
				dfs.plot <- input$dfs.plot
			}
			pwrFrame <- createPwrFrame(effectSizes=input$effectSize,
						   dfs=5:input$dfs,
						   dfNumerator=input$dfNumerator,
						   sig.level=input$sigLevel,
						   alternative=input$alternative,
						   test=input$test,
						   type=input$type,
						   standard=input$standard)
			if(input$plotFormat == "svg"){
				svg(file,width=input$plotWidth,height=input$plotHeight)
			}
			else{
				pdf(file,width=input$plotWidth,height=input$plotHeight)
			}
			print(plotPower(pwrFrame,guides=input$guides,power=power,df=dfs.plot))
			dev.off()
		}
		)
  
})