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| 1 | +<!-- |
| 2 | +
|
| 3 | +@license Apache-2.0 |
| 4 | +
|
| 5 | +Copyright (c) 2021 The Stdlib Authors. |
| 6 | +
|
| 7 | +Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | +you may not use this file except in compliance with the License. |
| 9 | +You may obtain a copy of the License at |
| 10 | +
|
| 11 | + http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | +
|
| 13 | +Unless required by applicable law or agreed to in writing, software |
| 14 | +distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | +See the License for the specific language governing permissions and |
| 17 | +limitations under the License. |
| 18 | +
|
| 19 | +--> |
| 20 | + |
| 21 | +<!-- lint disable maximum-heading-length --> |
| 22 | + |
| 23 | +# asinhBy |
| 24 | + |
| 25 | +> Compute the [hyperbolic arcsine][@stdlib/math/base/special/asinh] of each element retrieved from an input strided array via a callback function. |
| 26 | +
|
| 27 | +<section class="intro"> |
| 28 | + |
| 29 | +</section> |
| 30 | + |
| 31 | +<!-- /.intro --> |
| 32 | + |
| 33 | +<section class="usage"> |
| 34 | + |
| 35 | +## Usage |
| 36 | + |
| 37 | +```javascript |
| 38 | +var asinhBy = require( '@stdlib/math/strided/special/asinh-by' ); |
| 39 | +``` |
| 40 | + |
| 41 | +#### asinhBy( N, x, strideX, y, strideY, clbk\[, thisArg] ) |
| 42 | + |
| 43 | +Computes the [hyperbolic arcsine][@stdlib/math/base/special/asinh] of each element retrieved from an input strided array `x` via a callback function and assigns each result to an element in an output strided array `y`. |
| 44 | + |
| 45 | +```javascript |
| 46 | +function accessor( v ) { |
| 47 | + return v; |
| 48 | +} |
| 49 | + |
| 50 | +var x = [ 0.0, -0.0, 2.0, -2.0, 0.75 ]; |
| 51 | +var y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ]; |
| 52 | + |
| 53 | +asinhBy( x.length, x, 1, y, 1, accessor ); |
| 54 | +// y => [ 0.0, 0.0, ~1.444, ~-1.444, ~0.693 ] |
| 55 | +``` |
| 56 | + |
| 57 | +The function accepts the following arguments: |
| 58 | + |
| 59 | +- **N**: number of indexed elements. |
| 60 | +- **x**: input [`Array`][mdn-array], [`typed array`][mdn-typed-array], or an array-like object (excluding strings and functions). |
| 61 | +- **strideX**: index increment for `x`. |
| 62 | +- **y**: output [`Array`][mdn-array], [`typed array`][mdn-typed-array], or an array-like object (excluding strings and functions). |
| 63 | +- **strideY**: index increment for `y`. |
| 64 | +- **clbk**: callback function. |
| 65 | +- **thisArg**: execution context (_optional_). |
| 66 | + |
| 67 | +The invoked callback function is provided six arguments: |
| 68 | + |
| 69 | +- **value**: input array element. |
| 70 | +- **idx**: iteration index (zero-based). |
| 71 | +- **xi**: input array strided index (`offsetX + idx*strideX`). |
| 72 | +- **yi**: output array strided index (`offsetY + idx*strideY`). |
| 73 | +- **x**: input array/collection. |
| 74 | +- **y**: output array/collection. |
| 75 | + |
| 76 | +To set the callback execution context, provide a `thisArg`. |
| 77 | + |
| 78 | +```javascript |
| 79 | +function accessor( v ) { |
| 80 | + this.count += 1; |
| 81 | + return v; |
| 82 | +} |
| 83 | + |
| 84 | +var context = { |
| 85 | + 'count': 0 |
| 86 | +}; |
| 87 | + |
| 88 | +var x = [ 0.0, -0.0, 2.0, -2.0, 0.75 ]; |
| 89 | +var y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ]; |
| 90 | + |
| 91 | +asinhBy( x.length, x, 1, y, 1, accessor, context ); |
| 92 | +// y => [ 0.0, 0.0, ~1.444, ~-1.444, ~0.693 ] |
| 93 | + |
| 94 | +var cnt = context.count; |
| 95 | +// returns 8 |
| 96 | +``` |
| 97 | + |
| 98 | +The `N` and `stride` parameters determine which elements in `x` and `y` are accessed at runtime. For example, to index every other value in `x` and to index the first `N` elements of `y` in reverse order, |
| 99 | + |
| 100 | +```javascript |
| 101 | +function accessor( v ) { |
| 102 | + return v; |
| 103 | +} |
| 104 | + |
| 105 | +var x = [ 0.0, -0.0, 2.0, -2.0, 0.75, -0.68 ]; |
| 106 | +var y = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ]; |
| 107 | + |
| 108 | +asinhBy( 3, x, 2, y, -1, accessor ); |
| 109 | +// y => [ ~0.693, ~1.444, 0.0, 0.0, 0.0, 0.0 ] |
| 110 | +``` |
| 111 | + |
| 112 | +Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views. |
| 113 | + |
| 114 | +```javascript |
| 115 | +var Float64Array = require( '@stdlib/array/float64' ); |
| 116 | + |
| 117 | +function accessor( v ) { |
| 118 | + return v; |
| 119 | +} |
| 120 | + |
| 121 | +// Initial arrays... |
| 122 | +var x0 = new Float64Array( [ 0.0, -0.0, 2.0, -2.0, 0.75, -0.68 ] ); |
| 123 | +var y0 = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] ); |
| 124 | + |
| 125 | +// Create offset views... |
| 126 | +var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element |
| 127 | +var y1 = new Float64Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element |
| 128 | + |
| 129 | +asinhBy( 3, x1, -2, y1, 1, accessor ); |
| 130 | +// y0 => <Float64Array>[ 0.0, 0.0, 0.0, ~-0.636, ~-1.444, 0.0 ] |
| 131 | +``` |
| 132 | + |
| 133 | +#### asinhBy.ndarray( N, x, strideX, offsetX, y, strideY, offsetY, clbk\[, thisArg] ) |
| 134 | + |
| 135 | +Computes the [hyperbolic arcsine][@stdlib/math/base/special/asinh] of each element retrieved from an input strided array `x` via a callback function and assigns each result to an element in an output strided array `y` using alternative indexing semantics. |
| 136 | + |
| 137 | +```javascript |
| 138 | +function accessor( v ) { |
| 139 | + return v; |
| 140 | +} |
| 141 | + |
| 142 | +var x = [ 0.0, -0.0, 2.0, -2.0, 0.75 ]; |
| 143 | +var y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ]; |
| 144 | + |
| 145 | +asinhBy.ndarray( x.length, x, 1, 0, y, 1, 0, accessor ); |
| 146 | +// y => [ 0.0, 0.0, ~1.444, ~-1.444, ~0.693 ] |
| 147 | +``` |
| 148 | + |
| 149 | +The function accepts the following additional arguments: |
| 150 | + |
| 151 | +- **offsetX**: starting index for `x`. |
| 152 | +- **offsetY**: starting index for `y`. |
| 153 | + |
| 154 | +While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying `buffer`, the `offsetX` and `offsetY` parameters support indexing semantics based on starting indices. For example, to index every other value in `x` starting from the second value and to index the last `N` elements in `y`, |
| 155 | + |
| 156 | +```javascript |
| 157 | +function accessor( v ) { |
| 158 | + return v; |
| 159 | +} |
| 160 | + |
| 161 | +var x = [ 0.0, -0.0, 2.0, -2.0, 0.75, -0.68 ]; |
| 162 | +var y = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ]; |
| 163 | + |
| 164 | +asinhBy.ndarray( 3, x, 2, 1, y, -1, y.length-1, accessor ); |
| 165 | +// y => [ 0.0, 0.0, 0.0, ~-0.636, ~-1.444, 0.0 ] |
| 166 | +``` |
| 167 | + |
| 168 | +</section> |
| 169 | + |
| 170 | +<!-- /.usage --> |
| 171 | + |
| 172 | +<section class="notes"> |
| 173 | + |
| 174 | +## Notes |
| 175 | + |
| 176 | +- If a provided callback function does not return any value (or equivalently, explicitly returns `undefined`), the value is **ignored**. |
| 177 | + |
| 178 | + ```javascript |
| 179 | + function accessor() { |
| 180 | + // No-op... |
| 181 | + } |
| 182 | + |
| 183 | + var x = [ 0.0, -0.0, 2.0, -2.0, 0.75 ]; |
| 184 | + var y = [ 0.0, 0.0, 0.0, 0.0, 0.0 ]; |
| 185 | + |
| 186 | + asinhBy( x.length, x, 1, y, 1, accessor ); |
| 187 | + // y => [ 0.0, 0.0, 0.0, 0.0, 0.0 ] |
| 188 | + ``` |
| 189 | + |
| 190 | +</section> |
| 191 | + |
| 192 | +<!-- /.notes --> |
| 193 | + |
| 194 | +<section class="examples"> |
| 195 | + |
| 196 | +## Examples |
| 197 | + |
| 198 | +<!-- eslint no-undef: "error" --> |
| 199 | + |
| 200 | +```javascript |
| 201 | +var uniform = require( '@stdlib/random/base/uniform' ); |
| 202 | +var filledarray = require( '@stdlib/array/filled' ); |
| 203 | +var asinhBy = require( '@stdlib/math/strided/special/asinh-by' ); |
| 204 | +
|
| 205 | +function accessor( v, i ) { |
| 206 | + if ( (i%3) === 0 ) { |
| 207 | + // Simulate a "missing" value... |
| 208 | + return; |
| 209 | + } |
| 210 | + return v; |
| 211 | +} |
| 212 | +
|
| 213 | +var x = filledarray( 0.0, 10, 'generic' ); |
| 214 | +var y = filledarray( null, 10, 'generic' ); |
| 215 | +
|
| 216 | +var i; |
| 217 | +for ( i = 0; i < x.length; i++ ) { |
| 218 | + x[ i ] = uniform( -5.0, 5.0 ); |
| 219 | +} |
| 220 | +console.log( x ); |
| 221 | +console.log( y ); |
| 222 | +
|
| 223 | +asinhBy.ndarray( x.length, x, 1, 0, y, -1, y.length-1, accessor ); |
| 224 | +console.log( y ); |
| 225 | +``` |
| 226 | + |
| 227 | +</section> |
| 228 | + |
| 229 | +<!-- /.examples --> |
| 230 | + |
| 231 | +<section class="links"> |
| 232 | + |
| 233 | +[mdn-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array |
| 234 | + |
| 235 | +[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray |
| 236 | + |
| 237 | +[@stdlib/math/base/special/asinh]: https://github.com/stdlib-js/stdlib |
| 238 | + |
| 239 | +</section> |
| 240 | + |
| 241 | +<!-- /.links --> |
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