Module 3

#install necessary libraries
library(shiny)
library(ggplot2)
library(dplyr)

Link to the deployed shiny app: https://olia.shinyapps.io/shiny_app/

Code of app.R is shown below:

#load the data
data <-read.csv('cleaned-cdc-mortality-1999-2010-2.csv')

#select the data from the Year 2010 (for Question 1)
dataset_2010 <- subset(data,data$Year==2010)
#find out death causes for the Year 2010 (for Question 1)
death_causes_2010 <- unique(dataset_2010$ICD.Chapter)

#list of states 
states <- unique(data$State)
#death causes
death_causes <- unique(data$ICD.Chapter)
#years
years <- unique(data$Year)
#calculate population by year
population_by_year <- data %>% select(Year,Population) %>% group_by(Year) %>% summarise(Year,Population)


#Define server logic to plot various variables
server <- function(input, output) {
  
  
  #dataset for Question 1
  dataset_q1 <- reactive({
    
    #calculate number of deaths by state
    subset(dataset_2010,dataset_2010$ICD.Chapter==input$death_cause_2010) %>% select(State,Deaths) %>% group_by(State) %>% summarise(State,Deaths) %>% arrange(desc(Deaths))
    
  })
  
  
  #graph title for Question 1
  formulaText_q1 <- reactive({
    paste("Death Cause - ", input$death_cause_2010)
  })
  
  #return graph title for printing as a caption
  output$caption_q1  <- renderText({
    formulaText()
  })
  
  #generate a plot for Question 1
  output$plot_q1  <- renderPlot({
    #graph show number of deaths by state for a selected death cause
    ggplot(dataset_q1(), aes(reorder(State, Deaths), Deaths)) +
      geom_bar(position="dodge",stat="identity") + 
      labs(x="State", y = "Number of Deaths") +
      coord_flip() +
      ggtitle("Mortality Rate by State")
  })  
  
  
  
  #graph title for Question 2
  dataset_q2 <- reactive({
    #calculate percentage of deaths per year for a selected state and death cause
    subset(data,data$ICD.Chapter==input$death_cause & data$State==input$state) %>% select(Deaths,Year) %>% group_by(Year) %>% inner_join(population_by_year) %>% mutate(Deaths=(Deaths/Population)*100) %>% summarise(Deaths,Year)
   
  })
  
  
  #graph title for Question 2
  formulaText_q2 <- reactive({
    paste("Death Cause - ", input$death_cause)
  })
  
  #return graph title for printing as a caption
  output$caption_q2 <- renderText({
    formulaText_q2()
  })
  
  #generate a plot for Question 2
  output$plot_q2 <- renderPlot({
    ggplot(dataset_q2(), aes(Year, Deaths)) +
      geom_bar(position="dodge",stat="identity") + 
      labs(x="Year", y = "YearMortality Rate, %") +
      ggtitle("Mortality Rate by Death Cause by State")
  })
  
}


#define UI
ui <- fluidPage(
  
  navbarPage("",
             tabPanel(
               "Question 1",
               titlePanel("Mortality Rate From Partucular Causes Across Different States"),
                 
          #sidebar layout with input and output definitions for Question 1
                 sidebarLayout(
                   
                   #sidebar panel for inputs
                   sidebarPanel(
                     
                     #input: selector for variable death cause in 2010
                     selectInput("death_causes_2010_variable", 
                                 "Death Cause",death_causes_2010)
                      ),
                   
                   #main panel for displaying outputs
                   mainPanel(
                     
                     #output: formatted text for caption
                     h3(textOutput("caption")),
                     
                     #output: plot graph for a selected cause of death
                     plotOutput("plot_q1")
                     
                   )
             )),
             
             tabPanel(
               "Question 2",
               titlePanel("Mortality Rate From Partucular Causes by States per Year"),
               
          #sidebar layout with input and output definitions for Question 2
               sidebarLayout(
                 
                 #sidebar panel for inputs
                 sidebarPanel(
                   
                   #input: selector for variables state and death cause
                   selectInput("death_cause", "Select Death Cause",
                               death_causes),
                   selectInput("state", "Select State",
                               states)
                   
                   
                 ),
                 
                 #main panel for displaying outputs
                 mainPanel(
                   
                   #output: formatted text for caption
                   h3(textOutput("caption_q2")),
                   
                   #output: plot graph for a selected state and cause of death
                   plotOutput("plot_q2")
                   
                 
                   
                 )
               ))             
             
                          ))


#run shiny app
shinyApp(ui, server)