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o3de/Gems/PhysX/Code/NumericalMethods/Source/Optimization/Utilities.cpp

40 lines
1.4 KiB
C++

/*
* Copyright (c) Contributors to the Open 3D Engine Project. For complete copyright and license terms please see the LICENSE at the root of this distribution.
*
* SPDX-License-Identifier: Apache-2.0 OR MIT
*
*/
#include <NumericalMethods/Optimization.h>
#include <Optimization/Constants.h>
#include <Optimization/Utilities.h>
namespace NumericalMethods::Optimization
{
double FunctionValue(const Function& function, const VectorVariable& point)
{
return function.Execute(point.GetValues()).GetValue();
}
double DirectionalDerivative(const Function& function, const VectorVariable& point, const VectorVariable& direction)
{
return Gradient(function, point).Dot(direction);
}
VectorVariable Gradient(const Function& function, const VectorVariable& point)
{
const AZ::u32 dimension = point.GetDimension();
VectorVariable gradient(dimension);
VectorVariable direction(dimension);
for (AZ::u32 i = 0; i < dimension; i++)
{
direction[i] = 1.0;
double f_plus = FunctionValue(function, point + epsilon * direction);
double f_minus = FunctionValue(function, point - epsilon * direction);
gradient[i] = (f_plus - f_minus) / (2.0 * epsilon);
direction[i] = 0.0;
}
return gradient;
}
} // namespace NumericalMethods::Optimization