index.js

function $(selectorString, scope = document) {
  return scope.querySelector(selectorString);
}

function getSimilarityOfInput(scope = document, callback) {
  if ($("#get-similarity, .get-similarity", scope)) {
    $("#get-similarity, .get-similarity", scope).style.display = "none";
  }
  if ($("#spinner, .spinner", scope)) {
    $("#spinner, .spinner", scope).style.visibility = "visible";
  }
  $("#input, .input", scope)?.setAttribute("disabled", true);
  $("#input, .input", scope)?.classList.add("disabled");
  const sentence1 = $("#sentence1, .sentence1", scope)?.value;
  const sentence2 = $("#input, .input, .sentence2", scope)?.value;
  if (sentence1 && sentence2) {
    useModel(sentence1, sentence2, (similarity) => {
      showOutput(similarity, scope);
      if (callback) callback();
    });
  }
}

function showOutput(similarity, scope = document) {
  const percent = similarity * 100;
  if ($("#similarity, .similarity", scope)) {
    $("#similarity, .similarity", scope).innerText =
      getNDecimals(percent, 0) + "%";
  }
  if ($("#output, .output", scope)) {
    $("#output, .output", scope).style.visibility = "visible";
  }
  if ($("#get-similarity, .get-similarity", scope)) {
    $("#get-similarity, .get-similarity", scope).style.display = "block";
  }
  if ($("#spinner, .spinner", scope)) {
    $("#spinner, .spinner", scope).style.visibility = "hidden";
  }
  if ($("#input, .input", scope)) {
    $("#input, .input", scope).removeAttribute("disabled");
  }
  if ($("#input, .input", scope)) {
    $("#input, .input", scope).classList.remove("disabled");
  }
}

function getNDecimals(number, n) {
  return Math.round(number * 10 ** n) / 10 ** n;
}

// /**
//  * References:
//  *
//  * https://github.com/tensorflow/tfjs-models/tree/master/universal-sentence-encoder
//  * https://towardsdatascience.com/how-to-build-a-textual-similarity-analysis-web-app-aa3139d4fb71
//  * https://github.com/jinglescode/demos/tree/master/src/app/components/nlp-sentence-encoder
//  * https://towardsdatascience.com/how-to-measure-distances-in-machine-learning-13a396aa34ce
//  * https://en.wikipedia.org/wiki/Cosine_similarity
//  *
//  * */

// // require("@tensorflow/tfjs-node");
// // const use = require("@tensorflow-models/universal-sentence-encoder");

// // const sentence1 = "How's it going?";
// // const sentence2 = "How are you?";
// // useModel(sentence1, sentence2, output);
// function useModel(sentence1, sentence2, callback) {
//   // uses Universal Sentence Encoder (U.S.E.):
//   use.load().then((model) => {
//     embedSentences(model, sentence1, sentence2, callback);
//   });
// }

// function embedSentences(model, sentence1, sentence2, callback) {
//   const sentences = [sentence1, sentence2];
//   model.embed(sentences).then((embeddings) => {
//     const embeds = embeddings.arraySync();
//     const sentence1Embedding = embeds[0];
//     const sentence2Embedding = embeds[1];
//     getSimilarityPercent(sentence1Embedding, sentence2Embedding, callback);
//   });
// }

// function getSimilarityPercent(embed1, embed2, callback) {
//   const similarity = cosineSimilarity(embed1, embed2);
//   // cosine similarity -> % when doing text comparison, since cannot have -ve term frequencies: https://en.wikipedia.org/wiki/Cosine_similarity
//   if (callback) callback(similarity);
//   return similarity;
// }

// function cosineSimilarity(a, b) {
//   // https://towardsdatascience.com/how-to-build-a-textual-similarity-analysis-web-app-aa3139d4fb71

//   const magnitudeA = Math.sqrt(dotProduct(a, a));
//   const magnitudeB = Math.sqrt(dotProduct(b, b));
//   if (magnitudeA && magnitudeB) {
//     // https://towardsdatascience.com/how-to-measure-distances-in-machine-learning-13a396aa34ce
//     return dotProduct(a, b) / (magnitudeA * magnitudeB);
//   } else {
//     return 0;
//   }
// }

// function dotProduct(a, b) {
//   let sum = 0;
//   for (let i = 0; i < a.length; i++) {
//     sum += a[i] * b[i];
//   }
//   return sum;
// }