import torch


def make_seed(size, num_seeds, channel_n):
    """
    Create a seed state, where all cells are 0 except for the middle which is 1.0.
    First three channels (representing RGB) are kept as 0.

    Parameters
    ----------
    h: int
        Height of the state
    w: int
        Width of the state
    pool_size: int
        Number of seeds to create.
    channel_n: int
        Number of channels to represent state.

    Returns
    -------
    tensor
        Tensor of size (pool_size, channel_n, h, w).
    """
    h, w = size
    seed = torch.zeros((num_seeds, channel_n, h, w), dtype=torch.float32)
    seed[:, 3:, h//2, w//2] = 1.0
    return seed