def reduce_terms(term_doc_matrix, scores, num_term_to_keep=None):
		'''
		Parameters
		----------
		term_doc_matrix: TermDocMatrix or descendant
		scores: array-like
			Same length as number of terms in TermDocMatrix.
		num_term_to_keep: int, default=4000.
			Should be> 0. Number of terms to keep. Will keep between num_terms_to_keep/2 and num_terms_to_keep.

		Returns
		-------
		TermDocMatrix stripped of non-important terms., array of scores
		'''
		terms_to_show = AutoTermSelector.get_selected_terms(
			term_doc_matrix, scores, num_term_to_keep)
		return term_doc_matrix.remove_terms(set(term_doc_matrix.get_terms())
		                                    - set(terms_to_show))