js-regression

Package provides javascript implementation of linear regression and logistic regression

 

Install

``bash
npm install js-regression
`

Usage

$3

The sample code below illustrates how to run the multiple linear regression (polynomial in this case):

`javascript
var jsregression = require('js-regression');

// === training data generated from y = 2.0 + 5.0 x + 2.0 x^2 === //
var data = [];
for(var x = 1.0; x < 100.0; x += 1.0) {
var y = 2.0 + 5.0 x + 2.0 x x + Math.random() 1.0;
data.push([x, x * x, y]); // Note that the last column should be y the output
}

// === Create the linear regression === //
var regression = new jsregression.LinearRegression({
alpha: 0.001, //
iterations: 300,
lambda: 0.0
});
// can also use default configuration: var regression = new jsregression.LinearRegression();

// === Train the linear regression === //
var model = regression.fit(data);

// === Print the trained model === //
console.log(model);


// === Testing the trained linear regression === //
var testingData = [];
for(var x = 1.0; x < 100.0; x += 1.0) {
var actual_y = 2.0 + 5.0 x + 2.0 x x + Math.random() 1.0;
var predicted_y = regression.transform([x, x * x]);
console.log("actual: " + actual_y + " predicted: " + predicted_y);
}
`

$3

The sample code below illustrates how to run the logistic regression on the iris datsets to classify whether a data row belong to species Iris-virginica:

`javascript
var jsregression = require('js-regression');
var iris = require('js-datasets-iris');

// === Create the linear regression === //
var logistic = new jsregression.LogisticRegression({
alpha: 0.001,
iterations: 1000,
lambda: 0.0
});
// can also use default configuration: var logistic = new jsregression.LogisticRegression();

// === Create training data and testing data ===//
iris.shuffle();

var trainingDataSize = Math.round(iris.rowCount * 0.8);
var trainingData = [];
var testingData = [];
for(var i=0; i < iris.rowCount ; ++i) {
var row = [];
row.push(iris.data[i][0]); // sepalLength;
row.push(iris.data[i][1]); // sepalWidth;
row.push(iris.data[i][2]); // petalLength;
row.push(iris.data[i][3]); // petalWidth;
row.push(iris.data[i][4] == "Iris-virginica" ? 1.0 : 0.0); // output which is 1 if species is Iris-virginica; 0 otherwise
if(i < trainingDataSize) {
trainingData.push(row);
} else {
testingData.push(row);
}
}


// === Train the logistic regression === //
var model = logistic.fit(trainingData);

// === Print the trained model === //
console.log(model);

// === Testing the trained logistic regression === //
for(var i=0; i < testingData.length; ++i){
var probabilityOfSpeciesBeingIrisVirginica = logistic.transform(testingData[i]);
var predicted = logistic.transform(testingData[i]) >= logistic.threshold ? 1 : 0;
console.log("actual: " + testingData[i][4] + " probability of being Iris-virginica: " + probabilityOfSpeciesBeingIrisVirginica);
console.log("actual: " + testingData[i][4] + " predicted: " + predicted);
}

`

$3

The sample code below illustrates how to run the multi-class classifier on the iris datasets to classifiy the species of each data row:

`javascript
var classifier = new jsregression.MultiClassLogistic({
alpha: 0.001,
iterations: 1000,
lambda: 0.0
});

iris.shuffle();

var trainingDataSize = Math.round(iris.rowCount * 0.9);
var trainingData = [];
var testingData = [];
for(var i=0; i < iris.rowCount ; ++i) {
var row = [];
row.push(iris.data[i][0]); // sepalLength;
row.push(iris.data[i][1]); // sepalWidth;
row.push(iris.data[i][2]); // petalLength;
row.push(iris.data[i][3]); // petalWidth;
row.push(iris.data[i][4]); // output is species
if(i < trainingDataSize){
trainingData.push(row);
} else {
testingData.push(row);
}
}


var result = classifier.fit(trainingData);

console.log(result);

for(var i=0; i < testingData.length; ++i){
var predicted = classifier.transform(testingData[i]);
console.log("actual: " + testingData[i][4] + " predicted: " + predicted);
}
``

$3

Include the "node_modules/js-regression/build/jsregression.min.js" (or "node_modules/js-regression/src/jsregression.js") in your HTML \ tag

The codes in the following html files illustrates how to use them in html pages:

* example-binary-classifier.html
* example-multi-class-classifier.html
* example-regression.html
* example-regression-2.html
* example-regression-3.html