code: def decompose_delta(deltak):
      '''Decomposes the k-th order trend filtering matrix into a c-compatible set
      of arrays.'''
      if not isspmatrix_coo(deltak):
          deltak = coo_matrix(deltak)
      dk_rows = deltak.shape[0]
      dk_rowbreaks = np.cumsum(deltak.getnnz(1), dtype="int32")
      dk_cols = deltak.col.astype('int32')
      dk_vals = deltak.data.astype('double')
      return dk_rows, dk_rowbreaks, dk_cols, dk_valf decompose_delta(deltak):
      '''Decomposes the k-th order trend filtering matrix into a c-compatible set
      of arrays.'''
      if not isspmatrix_coo(deltak):
          deltak = coo_matrix(deltak)
      dk_rows = deltak.shape[0]
      dk_rowbreaks = np.cumsum(deltak.getnnz(1), dtype="int32")
      dk_cols = deltak.col.astype('int32')
      dk_vals = deltak.data.astype('double')
      return dk_rows, dk_rowbreaks, dk_cols, dk_vals
docs: Decomposes the k-th order trend filtering matrix into a c-compatible set
      of arrays.