TF-IDF SEO function for Google Sheets

tfidf.js

/**
 * Return the time that the referenced cell or range was last changed.
 * Initial use shows current time.
 *
 * @param {"keyword"}  term  La keyword a analizar
 * @param {"texto"}  flow  El texto que contiene la keyword
 * @param {"corpus"}  document  Todos los textos de tu sitio
 * @param {"verbose"}  verbose  VERDADERO o FALSO: muestra un detalle del análisis
 * @customfunction
 */
function tfidf(term, flow, document, verbose) {
  flow = flow.toLowerCase();
  term = term.toLowerCase();
   
  var flow_array = flow.trim().split(/\s+/);
  var words_in_flow = flow_array.length;
  
  //Contar veces que figura el term en el flow
  var term_repetition_in_flow = 0;
  for(var t=0; t<flow_array.length;t++){
    if(flow_array[t] == term){term_repetition_in_flow++;}
  }

  //Encontrar el TF
  var tf = term_repetition_in_flow / words_in_flow;
 
  
  //Contar cantidad de docs con el término
  var docs_with_term = 0;
  for(var c = 0; c<document.length;c++){
    var current_document = []
    current_document[c] = JSON.stringify(document[c]);
     current_document[c] = current_document[c].toLowerCase();
    if(current_document[c].indexOf(term) > -1) {docs_with_term++;}

  }
  

  var cant_documentos = document.length;
  terms_in_document = document.join().split(/\s+/).length+1;
  var idf = Math.log(cant_documentos/docs_with_term)/Math.log(10);
  var tfidf = tf*idf;
  if(verbose){
  return "Term repetition in flow: "+term_repetition_in_flow+"\nWords in flow: "+words_in_flow+"\nDocs with term: "+docs_with_term+"\nTotal docs in corpus: "+cant_documentos+"\nTF: "+tf+"\nIDF: "+idf+"\nFormula: "+tf+" * log("+cant_documentos+"/"+docs_with_term+")\nTF-IDF: "+tfidf;}
  if(!verbose){return tfidf;}
}