code: def mse(actual, prediction):
      filtered = ~np.isnan(actual)
      actual = actual[filtered]
      prediction = prediction[filtered]
      return np.mean(np.square(actual - prediction))
  
file_path: orbit/orbit/diagnostics/metrics.py
imports: import numpy
label_desc: Use image node_id 6 for calling a global function with example usage: mse(actual, prediction) and returns: np