code: def f(x):
      """Function to be approximated by polynomial interpolation."""
      return x * np.sin(x)
  
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 1 for calling a global function with example usage: f(x) and returns: unknown