refactor(LINREG): Expose Linear Regression

Author: bennycode

README.md

@@ -202,6 +202,7 @@ It is very important to do your own analysis before making any investment based
 
 - [Cloud9Trader Indicators (JavaScript)](https://github.com/Cloud9Trader/TechnicalIndicators)
 - [Crypto Trading Hub Indicators (TypeScript)](https://github.com/anandanand84/technicalindicators)
+- [Indicator TS](https://github.com/cinar/indicatorts)
 - [Jesse Trading Bot Indicators (Python)](https://docs.jesse.trade/docs/indicators/reference.html)
 - [LEAN Indicators](https://github.com/QuantConnect/Lean/tree/master/Indicators)
 - [libindicators (C#)](https://github.com/mgfx/libindicators)

src/BBANDS/BollingerBands.test.ts

@@ -63,6 +63,7 @@ describe('BollingerBands', () => {
     it('is compatible with results from Tulip Indicators (TI)', () => {
       // Test data verified with:
       // https://tulipindicators.org/bbands
+      // https://github.com/TulipCharts/tulipindicators/blob/v0.9.1/tests/untest.txt#L86
       const inputs = [
         81.59, 81.06, 82.87, 83.0, 83.61, 83.15, 82.84, 83.99, 84.55, 84.36, 85.53, 86.54, 86.89, 87.77, 87.29,
       ];

src/LINEAR_REGRESSION/LinearRegression.test.ts src/LINREG/LinearRegression.test.ts

@@ -5,6 +5,8 @@ import {NotEnoughDataError} from '../error/index.js';
 describe('LinearRegression', () => {
   describe('prediction (linreg)', () => {
     it('calculates the prediction values correctly', () => {
+      // Test data verified with:
+      // https://github.com/TulipCharts/tulipindicators/blob/v0.9.1/tests/untest.txt#L222
       const period = 5;
       const prices = [
         81.59, 81.06, 82.87, 83.0, 83.61, 83.15, 82.84, 83.99, 84.55, 84.36, 85.53, 86.54, 86.89, 87.77, 87.29,
@@ -24,6 +26,8 @@ describe('LinearRegression', () => {
 
   describe('intercept (linregintercept)', () => {
     it('calculates the intercept values correctly', () => {
+      // Test data verified with:
+      // https://github.com/TulipCharts/tulipindicators/blob/v0.9.1/tests/untest.txt#L226
       const period = 5;
       const prices = [
         81.59, 81.06, 82.87, 83.0, 83.61, 83.15, 82.84, 83.99, 84.55, 84.36, 85.53, 86.54, 86.89, 87.77, 87.29,
@@ -43,6 +47,8 @@ describe('LinearRegression', () => {
 
   describe('slope (linregslope)', () => {
     it('calculates the slope values correctly', () => {
+      // Test data verified with:
+      // https://github.com/TulipCharts/tulipindicators/blob/v0.9.1/tests/untest.txt#L230
       const period = 5;
       const prices = [
         81.59, 81.06, 82.87, 83.0, 83.61, 83.15, 82.84, 83.99, 84.55, 84.36, 85.53, 86.54, 86.89, 87.77, 87.29,

src/LINEAR_REGRESSION/LinearRegression.ts src/LINREG/LinearRegression.ts

@@ -150,10 +150,10 @@ export class FasterLinearRegression extends TechnicalIndicator<FasterLinearRegre
   }
 
   override getResultOrThrow(): FasterLinearRegressionResult {
-    if (this.prices.length < this.period) {
+    if (!this.result) {
       throw new NotEnoughDataError();
     }
-    return this.result!;
+    return this.result;
   }
 
   override get isStable(): boolean {

src/index.ts

@@ -29,7 +29,7 @@ export * from './SMA/SMA.js';
 export * from './STOCH/StochasticOscillator.js';
 export * from './STOCH/StochasticRSI.js';
 export * from './TR/TR.js';
-export * from './LINEAR_REGRESSION/LinearRegression.js';
+export * from './LINREG/LinearRegression.js';
 export * from './util/index.js';
 export * from './WMA/WMA.js';
 export * from './WSMA/WSMA.js';