code: def count_nan_elements(data):
      """Count the number of elements in 1D arrays that are nan values."""
      if data.ndim == 1:
          return np.isnan(data).sum()
  
imports: import numpy
  import warnings
  from yellowbrick.exceptions import DataWarning
label_desc: Use image node_id 5 for calling a global function with example usage: count_nan_elements(data) and returns: np