code: def x_only(x):
      cosx = np.cos(x)
      sinx = np.sin(x)
      return np.array(
          [
              [1, 0, 0],
              [0, cosx, -sinx],
              [0, sinx, cosx],
          ]
      )
  
file_path: nibabel/nibabel/tests/test_euler.py
imports: import math
  import numpy
  import pytest
  from numpy import pi
  from numpy.testing import assert_array_almost_equal, assert_array_equal
  from ..None import eulerangles
  from ..None import quaternions
label_desc: Use image node_id 1 for calling a global function with example usage: x_only(x) and returns: np