TypeError: tf.tensor(a).get(0) is not a function

Hello,

I am learning TensorFlow.js through an online course. we prepared a very simple KNN function by tfjs but on the teacher’s computer it works but on my computer no.

I installed the 1.7.0 version of TensorFlow ( because of the latest existed document in tfjs website is 1.7.0) Node version: v12.16.1

when I run node on the terminal the below error appears :

 .sort((a,b)=>{ return  a.get(0)>b.get(0) ? 1 : -1 ; })//return  a.get(0)>b.get(0) ? 1 : -1 ;
                                         ^
TypeError: a.get is not a function

it is my code :

require("@tensorflow/tfjs-node");
const tf = require("@tensorflow/tfjs");
const loadCSV = require("./load-csv.js");


function knn( features , labels, predictionPoint , k){
    return features
            .sub(predictionPoint)
            .pow(2)
            .sum(1)
            .pow(0.5)
            .expandDims(1)
            .concat(labels , 1)
            .unstack()
            .sort((a,b)=>{ return  a.get(0)>b.get(0) ? 1 : -1 ; })//return  a.get(0)>b.get(0) ? 1 : -1 ;
            .slice(0, k)
            .reduce((accumulated , thisObj ) => { 
                // return accumulated + thisObj.get(1) 
            }, 0)/k;

}

let { features , labels , testFeatures , testLabels } = loadCSV("./kc_house_data.csv" , {
    shuffle : true , 
    splitTest : 10,
    dataColumns: ['lat','long'],
    labelColumns: ['price']
});

const locations = tf.tensor( features );
const prices = tf.tensor( labels );
const weAreLookingFor =  tf.tensor( testFeatures[0] );

const result = knn ( locations, prices, weAreLookingFor , 10 );
console.log("KNN result is  : ",result);

I could not find any related issues about it. I am completely stuck because of this problem. Please Help !

[Famidoc]

It will work if change some codes to :

… .sort((a,b)=> a.arraySync()[0]> b.arraySync()[0]? 1:-1) .slice(0,k) .reduce((acc,pair)=>acc+pair.arraySync()[1],0)/k; …

[tafsiri]

get is a method on TensorBuffer (https://js.tensorflow.org/api/1.7.0/#tf.TensorBuffer.get) not Tensor