03 January 2026

Coursera Reproducible Pitch

MPG Analysis Shiny App

This Shiny application allows users to explore the relationship between different automobile characteristics and miles per gallon (MPG) using the mtcars dataset.

Motivation

  • Fuel efficiency is an important factor in automobile performance
  • MPG varies with vehicle weight, engine size, and transmission
  • This app provides an interactive way to understand these relationships

mtcars Dataset

Motor Trend Car Road Tests

The data was extracted from the 1974 Motor Trend US magazine, and comprises fuel consumption and 10 aspects of automobile design and performance for 32 automobiles (1973-74 models). ### Source Henderson and Velleman (1981), Building multiple regression models interactively. Biometrics, 37, 391-411.

library(datasets)
head(mtcars, 3)
##                mpg cyl disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4     21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag 21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
## Datsun 710    22.8   4  108  93 3.85 2.320 18.61  1  1    4    1

mtcars Dataset - Format

A data frame with 32 observations on 11 variables.

Index Field Detail
[, 1] mpg Miles/(US) gallon
[, 2] cyl Number of cylinders
[, 3] disp Displacement (cu.in.)
[, 4] hp Gross horsepower
[, 5] drat Rear axle ratio
[, 6] wt Weight (lb/1000)
[, 7] qsec 1/4 mile time
[, 8] vs V/S
[, 9] am Transmission (0 = automatic, 1 = manual)
[,10] gear Number of forward gears
[,11] carb Number of carburetors

Analysis - Main Code

  formulaTextPoint <- reactive({
    paste("mpg ~", "as.integer(", input$variable, ")")  })
  
  fit <- reactive({
    lm(as.formula(formulaTextPoint()), data=mpgData)  })
  ...
  output$fit <- renderPrint({
    summary(fit()) })
  
  output$mpgPlot <- renderPlot({
    with(mpgData, {
      plot(as.formula(formulaTextPoint()))
      abline(fit(), col=2)
    })  })

Application Features

  • Users can select different car variables
  • Reactive boxplots and regression models are displayed
  • Results update instantly based on user input

Conclusion

  • A simple and interactive MPG exploration tool
  • Demonstrates reactive programming using Shiny
  • Suitable for novice users and quick data exploration

See the Regression Models Course Project

  • URL: https://github.com/deepthiv16/Developing-Data-Products-Week-4-Course-Project.git
  • Find here all the data that have been use for this presentation and also for the first part of the data Science Project: “First, you will create a Shiny application and deploy it on Rstudio’s servers.Second, you will use Slidify or Rstudio Presenter to prepare a reproducible pitch presentation about your application.”