Plot the Plotly Graph Dynamically in the Shiny App in R - r

Question

I want to draw a Plotly graph in the Shiny App in R. I want the the functionality in such a way that I want to plot a certain number of points (say 20) in a loop.
This is my code for the Server.R :-
xAxis = vector("numeric", as.numeric(input$Generations))
yAxis = vector("numeric", as.numeric(input$Generations))
graphDF = data.frame(cbind(xAxis, yAxis))
for(i in 1 : 5)
{ output$GA = renderPlotly({
print(graphDF) # Testing
graphDF$yAxis[i] = i
graphDF$xAxis[i] = i
print(graphDF) # Testing
# Plotly functionality
p <- plot_ly(graphDF, x = graphDF$xAxis, y = graphDF$yAxis)
})
}
Any help would be most appreciated.
Kind Regards

Answer 1

This was more complicated than it looked. It looks like you want to iterate and create a series of plotly graphs, changing the data values as you go along.
Because the Generations slider re-initializes the vector to a new length,
and each iteration changes the state of the data being plotted, you can't just cascade reactive functions. Storing the state in a reactiveValues is a good way to handle this.
The major changes were as follows:
Added a reactiveValues to store xAxis and yAxis
Added an observeEvent to reinitialize those values when its value change
Added an "Iteration range" slider to drive the iteration (easier than a reactive timer). Note that it has an animate parameter that (probably) creates a reactive timer on its own.
Modified the plotly call to make it more conventional and avoid warnings.
The code:
library(shiny)
library(plotly)
u <- fluidPage(
titlePanel("Iterations of a plotly graph"),
sidebarLayout(
sidebarPanel(
sliderInput("Generations","Number of Generations:",
min = 1, max = 50, value = 20),
sliderInput("iter", "Iteration range:",
value = 1, min = 1, max = 1000, step = 1,
animate=animationOptions(interval=800, loop=T)),
p("To start click on the blue arrowhead")
),
mainPanel(
plotlyOutput("GA")
)
))
s <- shinyServer(function(input,output){
rv <- reactiveValues(xAxis=NULL,yAxis=NULL)
observeEvent(input$Generations,{
rv$xAxis=vector("numeric", as.numeric(input$Generations))
rv$yAxis=vector("numeric", as.numeric(input$Generations))
})
output$GA = renderPlotly({
rv$yAxis[input$iter] <- input$iter
rv$xAxis[input$iter] <- input$iter
gdf <- data.frame(xAxis=rv$xAxis, yAxis=rv$yAxis)
plot_ly(gdf, x = ~xAxis, y = ~yAxis, type="scatter",mode="markers")
})
})
shinyApp(u,s)
Because it is dynamic, you have to run it to see how it really works, but here is a screen shot after several iterations: