In this paper, we use discrete gradient methods for numerical solutions of mathematical models of epidemiology: a susceptible infected recovered infected (SIRI) model. The numerical results mimic the true and qualitatively correct behavior of the SIRI model. The first integrals (also known as the constant of motion) of the SIRI model obtained in literature using partial Lagrangian approach are well preserved by the discrete gradient method. The graphical results verify the advantages of the proposed schemes.

中文翻译：

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保留第一积分的数值求解SIRI流行病模型的离散梯度方法

在本文中，我们将离散梯度方法用于流行病学数学模型的数值解决方案：易感感染恢复感染（SIRI）模型。数值结果模拟了SIRI模型的真实和定性正确的行为。文献中使用局部拉格朗日方法获得的SIRI模型的第一积分（也称为运动常数）通过离散梯度法得到了很好的保留。图形结果验证了所提出方案的优点。