Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 | 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 9x 35x 35x 35x 35x 9x 9x 3x 3x 3x 3x 3x | /**
* @license Apache-2.0
*
* Copyright (c) 2026 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 cospi = require( '@stdlib/math/base/special/cospi' );
// MAIN //
/**
* Generates a cosine wave in a strided array.
*
* @private
* @param {PositiveInteger} N - number of indexed elements
* @param {PositiveInteger} period - period (i.e., the number of elements before a cosine wave repeats)
* @param {NonNegativeNumber} amplitude - peak amplitude
* @param {integer} phaseOffset - phase offset (in units of elements; zero-based). A negative offset translates a waveform to the left. A positive offset translates a waveform to the right
* @param {NumericArray} x - input array
* @param {integer} strideX - stride length
* @param {NonNegativeInteger} offsetX - starting index
* @returns {Object} input array object
*
* @example
* var toAccessorArray = require( '@stdlib/array/base/to-accessor-array' );
* var arraylike2object = require( '@stdlib/array/base/arraylike2object' );
*
* var x = toAccessorArray( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0, 7.0, -8.0 ] );
*
* var v = cosineWave( 4, 4, 1.0, 0, arraylike2object( x ), 2, 1 );
* // returns {...}
*/
function cosineWave( N, period, amplitude, phaseOffset, x, strideX, offsetX ) {
var theta;
var xbuf;
var set;
var ix;
var i;
var s;
// Cache reference to array data:
xbuf = x.data;
// Cache reference to the element accessor:
set = x.accessors[ 1 ];
ix = offsetX;
theta = -phaseOffset;
s = 2.0 / period;
for ( i = 0; i < N; i++ ) {
set( xbuf, ix, amplitude * cospi( s * theta ) );
theta += 1.0;
ix += strideX;
}
return x;
}
// EXPORTS //
module.exports = cosineWave;
|