6663b6c9
 adorian
projet complet av...
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#include <poincare/cosine.h>
#include <poincare/hyperbolic_cosine.h>
#include <poincare/complex.h>
extern "C" {
#include <assert.h>
}
#include <cmath>
namespace Poincare {
Cosine::Cosine() :
Function("cos")
{
}
Expression::Type Cosine::type() const {
return Type::Cosine;
}
Expression * Cosine::cloneWithDifferentOperands(Expression** newOperands,
int numberOfOperands, bool cloneOperands) const {
assert(newOperands != nullptr);
Cosine * c = new Cosine();
c->setArgument(newOperands, numberOfOperands, cloneOperands);
return c;
}
template<typename T>
Complex<T> Cosine::compute(const Complex<T> c, AngleUnit angleUnit) {
assert(angleUnit != AngleUnit::Default);
if (c.b() == 0) {
T input = c.a();
if (angleUnit == AngleUnit::Degree) {
input *= M_PI/180.0f;
}
T result = std::cos(input);
/* Cheat: openbsd trigonometric functions (cos, sin & tan) are numerical
* implementation and thus are approximative. The error epsilon is ~1E-7
* on float and ~1E-15 on double. In order to avoid weird results as
* cos(90) = 6E-17, we neglect the result when its ratio with the argument
* (pi in the exemple) is smaller than epsilon.
* We can't do that for all evaluation as the user can operate on values as
* small as 1E-308 (in double) and most results still be correct. */
if (input != 0 && std::fabs(result/input) <= epsilon<T>()) {
return Complex<T>::Float(0);
}
return Complex<T>::Float(result);
}
Complex<T> arg = Complex<T>::Cartesian(-c.b(), c.a());
return HyperbolicCosine::compute(arg);
}
}
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