def find_mathml(self,docid,position): """ Find a specific math expression :param docid: document number or -1 (to read query) :type docid: int :param position: relative number of math expr within document :type position: int :return MathML or None :rtype: string """ if docid < 0: # hack to allow for reading queries instead (ext,content) = self.read_doc_file(self.queries) else: (ext,content) = self.read_doc_file(self.find_doc_file(docid)) if ext == '.tex': if position > 0: print("Warning: .tex documents have only one expression; position %i ignored\n"%position) mathml = LatexToMathML.convert_to_mathml(content) else: maths = MathExtractor.math_tokens(content) if position >= len(maths): print("Cannot find MathML expression: position %i too large"%position) return None mathml = maths[position] return(mathml)