time-to-botec/js/node_modules/@stdlib/array/logspace/lib/logspace.js
NunoSempere b6addc7f05 feat: add the node modules
Necessary in order to clearly see the squiggle hotwiring.
2022-12-03 12:44:49 +00:00

88 lines
2.3 KiB
JavaScript

/**
* @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 pow = require( '@stdlib/math/base/special/pow' );
var isNumber = require( '@stdlib/assert/is-number' ).isPrimitive;
var isNonNegativeInteger = require( '@stdlib/assert/is-nonnegative-integer' ).isPrimitive;
var isnan = require( '@stdlib/math/base/assert/is-nan' );
// MAIN //
/**
* Generates a logarithmically spaced numeric array.
*
* @param {number} a - exponent of start value
* @param {number} b - exponent of end value
* @param {NonNegativeInteger} [len=10] - length of output array
* @throws {TypeError} first argument must be numeric
* @throws {TypeError} second argument must be numeric
* @throws {TypeError} third argument must be a nonnegative integer
* @returns {Array} logarithmically spaced numeric array
*
* @example
* var arr = logspace( 0, 2, 6 );
* // returns [ 1, ~2.5, ~6.31, ~15.85, ~39.81, 100 ]
*/
function logspace( a, b, len ) {
var arr;
var end;
var tmp;
var d;
var i;
if ( !isNumber( a ) || isnan( a ) ) {
throw new TypeError( 'invalid argument. Exponent of start value must be numeric. Value: `' + a + '`.' );
}
if ( !isNumber( b ) || isnan( b ) ) {
throw new TypeError( 'invalid argument. Exponent of stop value must be numeric. Value: `' + b + '`.' );
}
if ( arguments.length < 3 ) {
len = 10;
} else {
if ( !isNonNegativeInteger( len ) ) {
throw new TypeError( 'invalid argument. Length must be a nonnegative integer. Value: `' + len + '`.' );
}
if ( len === 0 ) {
return [];
}
}
// Calculate the increment:
end = len - 1;
d = ( b-a ) / end;
// Build the output array...
arr = [];
tmp = a;
arr.push( pow( 10, tmp ) );
for ( i = 1; i < end; i++ ) {
tmp += d;
arr.push( pow( 10, tmp ) );
}
arr.push( pow( 10, b ) );
return arr;
}
// EXPORTS //
module.exports = logspace;