Animated Line Geometry

This is an example for the line geometry, showing an animated plot

Output

#include "trase.hpp"
#include <fstream>

using namespace trase;

int main() {

  // create figure and axis
  auto fig = figure();
  auto ax = fig->axis();

  // set x steps, logistic parameter and create x and y vectors
  const int n = 100;
  const float dx = 12.f / static_cast<float>(n);
  const float k = 1.f;
  auto logistic = [k](const float x) { return 1.f / (1.f + std::exp(-k * x)); };
  std::vector<float> x = {-6};
  std::vector<float> y = {logistic(x.back())};

  // create the initial dataset and then plot it using a line geometry
  auto data = create_data().x(x).y(y);
  auto plt = ax->line(data);

  // loop through rest of the points, generating a new frame for every point
  for (int i = 1; i < n; ++i) {
    x.push_back(x.back() + dx);
    y.push_back(logistic(x.back()));
    auto data = create_data().x(x).y(y);
    plt->add_frame(data, (x.back() - x[0]) / 4.f);
  }

  // label axis
  ax->xlabel("x");
  ax->ylabel("y");

  // output to chosen backend
#ifdef TRASE_EXAMPLES_SVG_BACKEND
  std::ofstream out;
  out.open("example_animated_line.svg");
  BackendSVG backend(out);
  fig->draw(backend);
  out.close();
#endif
#ifdef TRASE_EXAMPLES_GL_BACKEND
  BackendGL backend;
  fig->show(backend);
#endif
}