gallery_hello_world.cpp

Hello World Example

This example demonstrates the most basic usage of the plotly.cpp library by creating a simple scatter plot with both line and marker visualization.

What You'll Learn

• Basic plot creation with scatter traces
• Layout configuration with titles
• Interactive browser display vs headless image export
• Command line argument parsing for different execution modes

Sample Output

The example creates a scatter plot with the following data points:

• X coordinates: [1, 2, 3, 4, 5]
• Y coordinates: [1, 4, 2, 8, 5]

The resulting plot shows both line connections and individual markers, with the title "Hello World!" displayed at the top.

Hello World Example Output

See also

plotly::Figure For the main plotting interface

parseGalleryArgs() For command line argument handling

 
#include "plotly/plotly.hpp"
#include "utils/arg_parser.hpp"
#include <vector>
 
auto main(int argc, char *argv[]) -> int {
  // Parse command line arguments for headless/interactive mode
  auto args = parseGalleryArgs(argc, argv);
 
  // Create a new figure instance
  plotly::Figure fig;
  fig.openBrowser(args.headless); // Configure browser opening behavior
 
  // Sample data points for demonstration
  std::vector<double> x = {1, 2, 3, 4, 5}; 
  std::vector<double> y = {1, 4, 2, 8, 5}; 
 
  // Create trace object with Plotly.js-compatible structure
  plotly::Object trace = {
      {"x", x}, {"y", y}, {"type", "scatter"}, {"mode", "lines+markers"}};
 
  // Create layout object with title
  plotly::Object layout = {{"title", {{"text", "Hello World!"}}}};
 
  // Generate the plot with trace data and layout configuration
  fig.newPlot(plotly::Array{trace}, layout);
 
  // Handle output based on execution mode
  if (!args.headless) {
    fig.waitClose(); // Wait until browser is closed
  } else {
    plotly::Object imageOpts = {
        {"format", "png"},          
        {"width", 800},             
        {"height", 600},            
        {"filename", "hello_world"} 
    };
    fig.downloadImage(imageOpts);
  }
 
  return 0; 
}