# Define sine function
if dde.backend.backend_name in ["tensorflow.compat.v1", "tensorflow"]:
    from deepxde.backend import tf

    sin = tf.sin
elif dde.backend.backend_name == "jax":
    import jax

    sin = jax.numpy.sin
elif dde.backend.backend_name == "paddle":
    import paddle

    sin = paddle.sin
elif dde.backend.backend_name == "pytorch":
    import torch

    sin = torch.sin