code: def _check_pca(res, pca_res):
      # Standardize output vector signs
      screen_pca_res = res2pos1(res["pca_res"])
      for key in pca_res:
          assert_almost_equal(pca_res[key], screen_pca_res[key])
  
imports: import os
  from os.path import join
  from warnings import catch_warnings, simplefilter
  import numpy
  import pytest
  from numpy.testing import assert_almost_equal, assert_array_equal
  import nipy
  from nipy.core.api import rollimg
  from nipy.testing import funcfile
  from nipy.testing.decorators import needs_mpl_agg
  from ...utils.pca import pca
  from ...utils.tests.test_pca import res2pos1
  from ..screens import screen, write_screen_res
  from ..timediff import time_slice_diffs
label_desc: Use image node_id 1 for calling a global function with example usage: _check_pca(res, pca_res) without return types