text: from ..utility.FloatTensor import *
  from .axang2rotm           import *
  from .rotm2affine          import *
  
  
  def rot_x(theta, affine=False, device='cuda:0'):
      """
      Creates a 3D rotation matrix around x axis with the specified angle in radians
  
      Parameters
      ----------
      theta : float
          angle in radians
      affine : bool (optional)
          if True the output will be a (4,4) matrix, (3,3) otherwise (default is False)
      device : str or torch.device (optional)
          the device where the tensor will be stored to (default is 'cuda:0')
  
      Returns
      -------
      Tensor
          a (3,3) or (4,4) rotation matrix
      """
  
      R = axang2rotm(FloatTensor([1, 0, 0], device=device), theta)
      if affine:
          R = rotm2affine(R)
      return R
  