matrix_inverse.cpp

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#include <poincare/matrix_inverse.h>
#include <poincare/matrix.h>
#include <poincare/complex.h>
#include <poincare/division.h>
#include <poincare/undefined.h>
#include <poincare/power.h>
extern "C" {
#include <assert.h>
}
#include <cmath>

namespace Poincare {

Expression::Type MatrixInverse::type() const {
  return Type::MatrixInverse;
}

Expression * MatrixInverse::clone() const {
  MatrixInverse * a = new MatrixInverse(m_operands, true);
  return a;
}

Expression * MatrixInverse::shallowReduce(Context& context, AngleUnit angleUnit) {
  Expression * e = Expression::shallowReduce(context, angleUnit);
  if (e != this) {
    return e;
  }
  Expression * op = editableOperand(0);
#if MATRIX_EXACT_REDUCING
  if (!op->recursivelyMatches(Expression::IsMatrix)) {
    detachOperand(op);
    return replaceWith(new Power(op, new Rational(-1), false), true)->shallowReduce(context, angleUnit);
  }
  if (op->type() == Type::Matrix) {
    Matrix * mat = static_cast<Matrix *>(op);
    if (mat->numberOfRows() != mat->numberOfColumns()) {
      return replaceWith(new Undefined(), true);
    }
  }
  return this;
#else
  detachOperand(op);
  return replaceWith(new Power(op, new Rational(-1), false), true)->shallowReduce(context, angleUnit);
#endif
}

// TODO: handle this exactly in shallowReduce for small dimensions.
template<typename T>
Expression * MatrixInverse::templatedApproximate(Context& context, AngleUnit angleUnit) const {
  Expression * input = operand(0)->approximate<T>(context, angleUnit);
  Expression * result = nullptr;
  if (input->type() == Type::Complex) {
    Complex<T> * c = static_cast<Complex<T> *>(input);
    result = new Complex<T>(Division::compute(Complex<T>::Cartesian(1, 0), *c));
  } else {
    assert(input->type() == Type::Matrix);
    result = static_cast<Matrix *>(input)->createInverse<T>();
  }
  if (result == nullptr) {
    result = new Complex<T>(Complex<T>::Float(NAN));
  }
  delete input;
  return result;
}

}