code: def test_single_array_input():
      pred = mx.np.array([[1, 2, 3, 4]])
      label = pred + 0.1
  
      mse = mx.gluon.metric.create("mse")
      mse.update(label, pred)
      _, mse_res = mse.get()
      np.testing.assert_almost_equal(mse_res, 0.01)
  
      mae = mx.gluon.metric.create("mae")
      mae.update(label, pred)
      mae.get()
      _, mae_res = mae.get()
      np.testing.assert_almost_equal(mae_res, 0.1)
  
      rmse = mx.gluon.metric.create("rmse")
      rmse.update(label, pred)
      rmse.get()
      _, rmse_res = rmse.get()
      np.testing.assert_almost_equal(rmse_res, 0.1)
  
imports: import mxnet
  from mxnet.test_utils import use_np
  import numpy
  import scipy
  from scipy.stats import pearsonr
  import json
  import math
  from common import xfail_when_nonstandard_decimal_separator
  from copy import deepcopy
label_desc: Use image node_id 15 for calling a global function with example usage: test_single_array_input() without return types