code: def f(x):
      n = x.shape[0]
      g2 = x.group2
      u = g2.unique()
      u.sort()
      uv = {v: k for k, v in enumerate(u)}
      mat = np.zeros((n, len(u)))
      for i in range(n):
          mat[i, uv[g2.iloc[i]]] = 1
      colnames = ["%d" % z for z in u]
      return mat, colnames
  
file_path: statsmodels/examples/python/variance_components.py
imports: import numpy
  import statsmodels.api
  from statsmodels.regression.mixed_linear_model import VCSpec
  import pandas
label_desc: Use image node_id 2 for calling a global function with example usage: f(x) and returns: mat,  colnames