library(shiny)

ui <- basicPage(
                plotOutput("plot1", click = "plot_click"),
                verbatimTextOutput("info"),
                plotOutput("plot2", click = "plot_click"),
                verbatimTextOutput("info2")
                )

server <- function(input, output) {

	nSubj       = 10
	nValPerSubj = 10
	mapRows = 5
	mapCols = 5

	vals = matrix(rnorm(nSubj), nrow = nSubj)

	maps = replicate(nSubj, matrix(rnorm(mapRows*mapCols),
	                               nrow = mapRows,
	                               ncol = mapCols))


	corMap = matrix(nrow = mapRows, ncol = mapCols)
	for(r in 1:mapRows){
		for(c in 1:mapCols){
			corMap[r, c] = cor(vals, sapply(1:nSubj, function(z) maps[r, c, z]))
		}
	}

	plotCell = function(r, c, vals, nSubj, corMap){
		cellVals = sapply(1:nSubj, function(z) maps[r, c, z])
		cellCor  =  corMap[r, c]
		plot(vals, cellVals, main = paste0("R = ", round(cellCor, 3)))
		abline(lm(vals ~ cellVals))
	}


	output$plot1 <- renderPlot({
		image(1:mapRows, 1:mapCols, corMap)
	})


	observe({

		if(is.null(input$plot_click)){ return(NULL) }
		r = round(input$plot_click$x)
		c = round(input$plot_click$y)
		z = round(corMap[r, c], 3)

		output$info <- renderPrint({
			c("Row" = r, "Column" = c, "Correlation" = z)
		})

		output$plot2 <- renderPlot({
			plotCell(r, c, vals, nSubj, corMap)
		})

		output$info2 <- renderPrint({
			cellVals = sapply(1:nSubj, function(z) maps[r, c, z])
			cbind("Values" = vals, "Cell Values" = cellVals)
		})

	})


}

shinyApp(ui, server)