Part of the answer refers to GPT,

FDTD(Finite-Difference Time-Domain) is a numerical method used to simulate electromagnetic fields. Its working principle is to discretize a high-dimensional problem into a series of lower-dimensional problems by using the numerical difference technique according to the electromagnetic field equation. Reuse the computer to solve these low dimensional problems and thus solve the originally high dimensional problems.

Errors may occur when using the FDTD method. This may be because when FDTD method is used, there may be some errors in establishing the model, such as not describing the field source correctly, losing some important characteristics of the physical entity, not considering the boundary conditions or ignoring the attenuation characteristics of some physical entity. Alternatively, there may be problems with some software tool on the computer, such as incorrect code implementation, memory not large enough to hold large amounts of data, or incorrect boundary conditions.

In order to solve these problems, it is necessary to carefully check whether there are any problems in the established model: check whether the field source is correctly described, whether the important characteristics of the physical entity are taken into account, whether the boundary conditions are normal, whether the attenuation characteristics of the physical entity are taken into account. The next step is to check that the code implementation is correct: whether there are omissions or errors, whether the memory can hold large amounts of data, and whether the boundary conditions are normal.

In addition, you should also try to test the code implementation and boundary conditions used to see if you can get the desired effect. If none of the above methods solve the problem, consider a new approach to try to solve the problem, such as run time optimization, cutting the numerical simulation area, or using other numerical methods.

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