code: def g(x):
      """Function to be approximated by periodic spline interpolation."""
      return np.sin(x) - 0.7 * np.cos(x * 3)
  
imports: import matplotlib.pyplot
  import numpy
  from sklearn.linear_model import Ridge
  from sklearn.pipeline import make_pipeline
  from sklearn.preprocessing import PolynomialFeatures, SplineTransformer
label_desc: Use image node_id 2 for calling a global function with example usage: g(x) and returns: unknown