chore: fix JavaScript lint errors (issue #5377)

Author: suii2210

lib/node_modules/@stdlib/math/base/special/sqrt/scripts/precision.js

@@ -0,0 +1,121 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2018 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+
+'use strict';
+
+// MODULES //
+
+var log = require( '@stdlib/console/log' );
+var abs = require( '@stdlib/math/base/special/abs' );
+var sqrt = require( './../lib' );
+
+
+// FUNCTIONS //
+
+/**
+* Computes a rough square root approximation using a small fixed number of Newton iterations.
+*
+* @private
+* @param {number} x - input value
+* @returns {number} approximate square root
+*/
+function approxSqrt( x ) {
+	var guess;
+	var i;
+
+	if ( x < 0.0 ) {
+		return NaN;
+	}
+	if ( x === 0.0 ) {
+		return 0.0;
+	}
+	guess = ( x > 1.0 ) ? x / 2.0 : 1.0;
+	for ( i = 0; i < 5; i++ ) {
+		guess = 0.5 * ( guess + ( x / guess ) );
+	}
+	return guess;
+}
+
+/**
+* Computes the arithmetic mean.
+*
+* @private
+* @param {Array<number>} values - input array
+* @returns {number} mean value
+*/
+function mean( values ) {
+	var sum;
+	var i;
+
+	if ( values.length === 0 ) {
+		return NaN;
+	}
+	sum = 0.0;
+	for ( i = 0; i < values.length; i++ ) {
+		sum += values[ i ];
+	}
+	return sum / values.length;
+}
+
+/**
+* Computes the relative error between two numbers.
+*
+* @private
+* @param {number} value - computed value
+* @param {number} expected - reference value
+* @returns {number} relative error
+*/
+function relativeError( value, expected ) {
+	var denom = ( expected === 0.0 ) ? 1e-16 : expected;
+	return abs( ( value - expected ) / denom );
+}
+
+
+// MAIN //
+
+/**
+* Evaluate the mean relative error between a simple Newton approximation and `@stdlib`'s sqrt implementation.
+*
+* @private
+*/
+function main() {
+	var approx;
+	var errors;
+	var expected;
+	var values;
+	var i;
+
+	values = [
+		0.5,
+		1.5,
+		2.5,
+		10.0,
+		25.0,
+		100.0
+	];
+	errors = [];
+	for ( i = 0; i < values.length; i++ ) {
+		expected = sqrt( values[ i ] );
+		approx = approxSqrt( values[ i ] );
+		errors.push( relativeError( approx, expected ) );
+	}
+	log( 'Mean relative error (approx vs @stdlib sqrt): %d', mean( errors ) );
+}
+
+main();