#include "linear_model.h"
#include <math.h>
#include <assert.h>

namespace Regression {

double LinearModel::evaluate(double * modelCoefficients, double x) const {
  double a = modelCoefficients[0];
  double b = modelCoefficients[1];
  return a*x+b;
}

double LinearModel::partialDerivate(double * modelCoefficients, int derivateCoefficientIndex, double x) const {
  if (derivateCoefficientIndex == 0) {
    // Derivate: x
    return x;
  }
  if (derivateCoefficientIndex == 1) {
    // Derivate: 1;
    return 1;
  }
  assert(false);
  return 0.0;
}

}