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epsilon-master/poincare/src/arc_sine.cpp 1.48 KB
6663b6c9   adorian   projet complet av...
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  #include <poincare/arc_sine.h>
  #include <poincare/trigonometry.h>
  #include <poincare/simplification_engine.h>
  extern "C" {
  #include <assert.h>
  }
  #include <cmath>
  
  namespace Poincare {
  
  Expression::Type ArcSine::type() const {
    return Type::ArcSine;
  }
  
  Expression * ArcSine::clone() const {
    ArcSine * a = new ArcSine(m_operands, true);
    return a;
  }
  
  Expression * ArcSine::shallowReduce(Context& context, AngleUnit angleUnit) {
    Expression * e = Expression::shallowReduce(context, angleUnit);
    if (e != this) {
      return e;
    }
  #if MATRIX_EXACT_REDUCING
    if (operand(0)->type() == Type::Matrix) {
      return SimplificationEngine::map(this, context, angleUnit);
    }
  #endif
    return Trigonometry::shallowReduceInverseFunction(this, context, angleUnit);
  }
  
  template<typename T>
  std::complex<T> ArcSine::computeOnComplex(const std::complex<T> c, AngleUnit angleUnit) {
    std::complex<T> result = std::asin(c);
    /* asin has a branch cut on ]-inf, -1[U]1, +inf[: it is then multivalued on
     * this cut. We followed the convention chosen by the lib c++ of llvm on
     * ]-inf+0i, -1+0i[ (warning: asin takes the other side of the cut values on
     * ]-inf-0i, -1-0i[) and choose the values on ]1+0i, +inf+0i[ to comply with
     * asin(-x) = -asin(x) and tan(arcsin(x)) = x/sqrt(1-x^2). */
    if (c.imag() == 0 && c.real() > 1) {
      result.imag(-result.imag()); // other side of the cut
    }
    result = Trigonometry::RoundToMeaningfulDigits(result);
    return Trigonometry::ConvertRadianToAngleUnit(result, angleUnit);
  }
  
  }