Esse projeto nasceu de uma necessidade real: queria entender melhor como o IMC se comporta visualmente, nao apenas como um numero solto. A aplicacao Shiny calcula o Indice de Massa Corporal (IMC) do usuario com base em altura, peso, idade e genero, e entrega tres visualizacoes interativas que colocam esse numero em contexto — uma escala comparativa, uma distribuicao populacional e uma projecao temporal de diferentes cenarios.
O repositorio tambem inclui uma apresentacao em 5 slides (R Markdown / ioslides) que explica a logica do app, adequada para entrega academica.
O diagrama abaixo mostra o fluxo completo desde a entrada do usuario ate as saidas visuais:
flowchart TD
A([Usuario]) --> B[Formulario de Entrada\nAltura · Peso · Idade · Genero]
B --> C{Botao\nCalcular IMC}
C --> D[Calculo do IMC\nIMC = Peso / Altura²]
D --> E{Classificacao\nde Categoria}
E --> F[Abaixo do Peso\nIMC menor que 18.5]
E --> G[Peso Normal\nIMC 18.5 - 24.9]
E --> H[Sobrepeso\nIMC 25 - 29.9]
E --> I[Obesidade\nIMC maior ou igual a 30]
F & G & H & I --> J[Recomendacoes\nPersonalizadas]
D --> K[Escala IMC\nGrafico de faixa colorida]
D --> L[Comparacao Populacional\nDistribuicao simulada com n=2200]
D --> M[Projecao Temporal\nCenarios de 24 semanas]
J --> N([Painel de Resultados])
K --> N
L --> O([Aba Visualizacao])
M --> P([Aba IMC ao Longo do Tempo])
- Calculo do IMC: formula padrao da OMS — peso (kg) dividido pelo quadrado da altura (m)
- Classificacao em 4 categorias: Abaixo do Peso, Normal, Sobrepeso e Obesidade
- Recomendacoes personalizadas: sugestoes especificas por categoria, exibidas logo apos o calculo
- Escala visual do IMC: grafico de faixas coloridas com marcador na posicao do usuario
- Comparacao com populacao simulada: distribuicao de 2.200 individuos com histograma e curva de densidade
- Projecao de 24 semanas: tres cenarios — manter, perder 0,5 kg/semana ou ganhar 0,5 kg/semana
1. Clone o repositorio:
git clone https://github.com/galafis/Course-Project-Shiny-Application-and-Reproducible-Pitch.git2. Instale os pacotes necessarios (se ainda nao tiver):
install.packages(c("shiny", "ggplot2"))3. Execute o aplicativo:
shiny::runApp("app")4. Como usar o app:
- Informe sua altura em centimetros
- Informe seu peso em quilogramas
- Ajuste a idade no slider
- Selecione o genero
- Clique em "Calculate BMI"
- Explore as tres abas de resultado e visualizacao
Uma apresentacao de 5 slides em R Markdown / ioslides esta disponivel em presentation/presentation.Rmd. Para executar:
rmarkdown::run("presentation/presentation.Rmd")Course-Project-Shiny-Application-and-Reproducible-Pitch/
├── app/
│ ├── ui.R # Interface do usuario (sidebarLayout + tabsetPanel)
│ └── server.R # Logica do servidor, calculos e graficos ggplot2
├── presentation/
│ ├── presentation.Rmd # Apresentacao em 5 slides (ioslides)
│ └── styles.css # Estilos personalizados para a apresentacao
├── images/
│ ├── bmi_logo.png # Logo do projeto
│ └── bmi_preview.png # Preview para documentacao
└── README.md
This interactive Shiny application calculates the user's Body Mass Index (BMI) based on height, weight, age, and gender, and delivers three interactive visualizations to put that number in context: a color-coded BMI scale, a simulated population distribution, and a 24-week projection under three different weight scenarios.
The repository also includes a 5-slide reproducible pitch presentation (R Markdown / ioslides) suitable for academic submission.
The diagram below shows the complete data flow from user input to visual outputs:
flowchart TD
A([User]) --> B[Input Form\nHeight · Weight · Age · Gender]
B --> C{Calculate BMI\nButton}
C --> D[BMI Calculation\nBMI = Weight / Height²]
D --> E{Category\nClassification}
E --> F[Underweight\nBMI less than 18.5]
E --> G[Normal Weight\nBMI 18.5 - 24.9]
E --> H[Overweight\nBMI 25 - 29.9]
E --> I[Obese\nBMI 30 or greater]
F & G & H & I --> J[Personalized\nRecommendations]
D --> K[BMI Gauge\nColor-band scale chart]
D --> L[Population Comparison\nSimulated distribution n=2200]
D --> M[BMI Projection\n24-week scenarios]
J --> N([Results Panel])
K --> N
L --> O([Visualization Tab])
M --> P([BMI Over Time Tab])
- BMI Calculation: WHO standard formula — weight (kg) divided by height squared (m)
- 4-category classification: Underweight, Normal Weight, Overweight, Obese
- Personalized recommendations: category-specific health suggestions rendered immediately after calculation
- BMI gauge visualization: color-banded scale chart with a marker at the user's position
- Population comparison: simulated distribution of 2,200 individuals rendered as a histogram with density curve
- 24-week BMI projection: three selectable scenarios — maintain, lose 0.5 kg/week, or gain 0.5 kg/week
Body Mass Index (BMI) is a screening tool used to identify weight categories that may be associated with health risks. It is calculated as:
BMI = weight (kg) / height (m)²
| Category | BMI Range |
|---|---|
| Underweight | Less than 18.5 |
| Normal weight | 18.5 to 24.9 |
| Overweight | 25.0 to 29.9 |
| Obese | 30.0 or greater |
Note: BMI is a population-level screening tool and does not account for muscle mass, bone density, or fat distribution. Always consult a healthcare professional for personalized medical advice.
1. Clone the repository:
git clone https://github.com/galafis/Course-Project-Shiny-Application-and-Reproducible-Pitch.git2. Install required packages:
install.packages(c("shiny", "ggplot2"))3. Launch the app:
shiny::runApp("app")4. Using the app:
- Enter your height in centimeters
- Enter your weight in kilograms
- Select your age using the slider
- Choose your gender
- Click "Calculate BMI"
- View your results and explore the three visualization tabs
A 5-slide reproducible pitch presentation is available in the presentation/ folder. It covers:
- Purpose and features of the BMI Calculator
- How BMI is calculated and its categories
- Interactive features of the application
- Sample visualizations from the app
- How to access and run the application
To view the presentation:
rmarkdown::run("presentation/presentation.Rmd")| Component | Technology |
|---|---|
| Language | R |
| Web Framework | Shiny |
| Visualization | ggplot2 |
| Presentation | R Markdown + ioslides |
| Styling | Custom CSS |
Course-Project-Shiny-Application-and-Reproducible-Pitch/
├── app/
│ ├── ui.R # User interface (sidebarLayout + tabsetPanel)
│ └── server.R # Server logic, calculations, and ggplot2 charts
├── presentation/
│ ├── presentation.Rmd # 5-slide ioslides pitch presentation
│ └── styles.css # Custom presentation styles
├── images/
│ ├── bmi_logo.png # Project logo
│ └── bmi_preview.png # Preview screenshot for documentation
└── README.md
- Additional health metrics beyond BMI (body fat percentage, waist-to-height ratio)
- Data persistence to track BMI changes over time
- PDF/CSV export functionality for health reports
- Mobile-responsive layout improvements
This project is licensed under the MIT License. See the LICENSE file for details.
Created by Gabriel Demetrios Lafis — May 28, 2025