Shiny test

server.R

library(shiny)
library(ggplot2)
library(kernlab)
library(dplyr)
library(magrittr)

shinyServer(function(input, output){
  output$distPlot = reactivePlot(function(){
    param = 10 ^ input$param 
    #package 'kernlab' = kernel pca
    
    data(iris)
    iris_data = iris[, 1:4]
    iris_lab = iris[, 5]
    
    #kernel pca
    #kernel = gaussian, sigma=0.0003
    #feature dim =2
    result = kpca(~., data=iris_data, features=2, kpar=list(sigma=param))
    
    df = rotated(result)
    df_lab = df %>% 
      as.data.table %>% 
      cbind(iris_lab) %>% 
      setnames(c("x", "y","species"))
    title = paste( "kernel PCA", "(parameter sigma = ", param, ")")
    gp = ggplot(df_lab, aes(x=x, y=y, shape=species, col = species)) + 
      geom_point(size=4) + ggtitle(title) + 
      theme(plot.title = element_text(size = 20, face = "bold"))
    print(gp)
    
    
  })
})

ui.R

library(shiny)
shinyUI(
  pageWithSidebar(
    headerPanel("PCA (Gaussian kernel)"), 
    sidebarPanel(
      sliderInput("param", 
                  "parameter: log_10 (sigma)",
                  min = -4, 
                  max = 4, 
                  step = 0.5,
                  value = 0,
                  animate = animationOptions(interval=1250, loop=T))
      ),
    mainPanel(
      plotOutput("distPlot")
    )
  )
)