quadratic_model.cpp
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#include "quadratic_model.h"
#include "../../shared/poincare_helpers.h"
#include <math.h>
#include <assert.h>
#include "../../poincare/include/poincare_layouts.h"
using namespace Poincare;
using namespace Shared;
namespace Regression {
ExpressionLayout * QuadraticModel::layout() {
static ExpressionLayout * layout = nullptr;
if (layout == nullptr) {
const ExpressionLayout * layoutChildren[] = {
new CharLayout('a', KDText::FontSize::Small),
new CharLayout(Ion::Charset::MiddleDot, KDText::FontSize::Small),
new CharLayout('X', KDText::FontSize::Small),
new VerticalOffsetLayout(
new CharLayout('2', KDText::FontSize::Small),
VerticalOffsetLayout::Type::Superscript,
false),
new CharLayout('+', KDText::FontSize::Small),
new CharLayout('b', KDText::FontSize::Small),
new CharLayout(Ion::Charset::MiddleDot, KDText::FontSize::Small),
new CharLayout('X', KDText::FontSize::Small),
new CharLayout('+', KDText::FontSize::Small),
new CharLayout('c', KDText::FontSize::Small),
};
layout = new HorizontalLayout(layoutChildren, 10, false);
}
return layout;
}
Expression * QuadraticModel::simplifiedExpression(double * modelCoefficients, Poincare::Context * context) {
double a = modelCoefficients[0];
double b = modelCoefficients[1];
double c = modelCoefficients[2];
Expression * ax2Expression = new Multiplication(
new Decimal(a),
new Power(
new Symbol('x'),
new Decimal(2.0),
false),
false);
Expression * bxExpression = new Multiplication(
new Decimal(b),
new Symbol('x'),
false);
Expression * cExpression = new Decimal(c);
Expression * const operands[] = {ax2Expression, bxExpression, cExpression};
Expression * result = new Addition(operands, 3, false);
PoincareHelpers::Simplify(&result, *context);
return result;
}
double QuadraticModel::evaluate(double * modelCoefficients, double x) const {
double a = modelCoefficients[0];
double b = modelCoefficients[1];
double c = modelCoefficients[2];
return a*x*x+b*x+c;
}
double QuadraticModel::partialDerivate(double * modelCoefficients, int derivateCoefficientIndex, double x) const {
if (derivateCoefficientIndex == 0) {
// Derivate: x^2
return x*x;
}
if (derivateCoefficientIndex == 1) {
// Derivate: x
return x;
}
if (derivateCoefficientIndex == 2) {
// Derivate: 1
return 1;
}
assert(false);
return 0.0;
}
}