def positionalencoding2d(d_model, height, width):
    """
    :param d_model: dimension of the model
    :param height: height of the positions
    :param width: width of the positions
    :return: d_model*height*width position matrix
    """
    if d_model % 4 != 0:
        raise ValueError("Cannot use sin/cos positional encoding with "
                         "odd dimension (got dim={:d})".format(d_model))
    pe = torch.zeros([d_model, height, width])
    # Each dimension use half of d_model
    d_model = int(d_model / 2)
    div_term = torch.exp(torch.arange(0., d_model, 2) *
                          -(math.log(10000.0) / d_model))
    pos_w = torch.arange(0., width, dtype=torch.float32).unsqueeze(1)
    pos_h = torch.arange(0., height, dtype=torch.float32).unsqueeze(1)

    pe[0:d_model:2, :, :] = torch.sin(pos_w * div_term).transpose(0, 1).unsqueeze(1).repeat(1, height, 1)
    pe[1:d_model:2, :, :] = torch.cos(pos_w * div_term).transpose(0, 1).unsqueeze(1).repeat(1, height, 1)
    pe[d_model::2, :, :] = torch.sin(pos_h * div_term).transpose(0, 1).unsqueeze(2).repeat(1, 1, width)
    pe[d_model + 1::2, :, :] = torch.cos(pos_h * div_term).transpose(0, 1).unsqueeze(2).repeat(1, 1, width)

    return pe

    :param d_model: dimension of the model
    :param height: height of the positions
    :param width: width of the positions
    :return: d_model*height*width position matrix
    
pytorchocr/modeling/transforms/tbsrn.py