pi.cpp

//
// This file is part of the course materials for AMATH483/583 at the University of Washington,
// Spring 2019
//
// Licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
// https://creativecommons.org/licenses/by-nc-sa/4.0/
//
// Author: Andrew Lumsdaine
//

#include <cmath>
#include <iostream>
#define WITHOUT_NUMPY
#include "matplotlibcpp.h"

namespace plt = matplotlibcpp;


int main () {
  double pi = std::acos(-1.0);  // C++ does not mandate a value for pi

  plt::figure_size(1280, 960);  // Initialize a 1280 X 960 figure

  std::vector<double> x(1024);  // Create two vectors
  std::vector<double> y(1024);

  // Fill in x with values from 0 to 4*pi (equally spaced)
  for (int i = 0; i < 1024; ++i) {
    x[i] = i * 4 * pi / 1023; // WRITE ME
  }

  // Fill in y with sin of x
  for (int i = 0; i < 1024; ++i) {
    y[i] = std::sin(x[i]); // WRITE ME
  }

  // Check that the last value of y has the right value
  if (std::abs(x[1023] - 4.0*pi) < 1.0e-12) {
    std::cout << "Pass" << std::endl;
  } else {
    std::cout << "Fail" << " " << std::abs(x[1023] - 4.0*pi) <<std::endl;
  }


  plt::plot(x,y);

  plt::save("sinx.png");

  return 0;
}