// include libraries
#include <iostream>              // for printing
#include "../include/gcem.hpp"

// exponential and natural logarithm functions

double exp_val_1 = gcem::exp(3);
double log_val_1 = gcem::log(2);

// compare with the standard library

double exp_val_2 = std::exp(3);
double log_val_2 = std::log(2);

std::cout << "exp(3) = " << exp_val_1 << std::endl;
std::cout << "error = " << gcem::abs(exp_val_1 - exp_val_2) << std::endl;

// trig functions

double pi_dbl  = double(GCEM_PI);
double hpi_dbl = double(GCEM_HALF_PI);

double sin_val_1 = gcem::sin(pi_dbl);
double sin_val_2 = gcem::sin(hpi_dbl);

std::cout << "sin(pi)   = " << sin_val_1 << std::endl;
std::cout << "sin(pi/2) = " << sin_val_2 << std::endl;

std::cout << "gcem::tan(pi/2) = " << gcem::tan(hpi_dbl) << std::endl;
std::cout << "std::tan(pi/2)  = " << std::tan(hpi_dbl) << std::endl;

std::cout << "|gcem::tan(0.9) -  std::tan(0.9)| = " << gcem::abs(gcem::tan(1.5) - std::tan(1.5)) << std::endl;

// hyperbolic functions

constexpr double cosh_val = gcem::cosh(0.3);
constexpr double inp_val  = gcem::acosh(cosh_val);

std::cout << "gcem::cosh(0.3) = " << cosh_val << std::endl;
std::cout << "gcem::acosh(gcem::cosh(0.3)) = " << inp_val << std::endl;

// define some storage
double erf_inp_val, erf_val;
double a_par, b_par;
double ig_inp_val, bt_inp_val;
double ig_val, bt_val;

// Gaussian error function
erf_inp_val = 1.2;
erf_val = gcem::erf(erf_inp_val);

std::cout << "gcem::erf(" << erf_inp_val << ") = " << erf_val << std::endl;

// regularied lower incomplete gamma function
a_par = 3;
ig_inp_val = 4;

ig_val = gcem::incomplete_gamma(a_par,ig_inp_val);

std::cout << "gcem::incomplete_gamma(" << a_par << "," << ig_inp_val << ") = " << ig_val << std::endl;

// regularied lower incomplete beta function
a_par = 6;
b_par = 5;
bt_inp_val = 0.7;

bt_val = gcem::incomplete_beta(a_par,b_par,bt_inp_val);

std::cout << "gcem::incomplete_gamma(" << a_par << "," << b_par << "," << bt_inp_val << ") = " << bt_val << std::endl;