|  | 
|  | 1 | +<!-- | 
|  | 2 | +
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|  | 3 | +@license Apache-2.0 | 
|  | 4 | +
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|  | 5 | +Copyright (c) 2025 The Stdlib Authors. | 
|  | 6 | +
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|  | 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 | +
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|  | 11 | + http://www.apache.org/licenses/LICENSE-2.0 | 
|  | 12 | +
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|  | 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 | +# sger | 
|  | 22 | + | 
|  | 23 | +> Perform the rank 1 operation `A = α*x*y^T + A`. | 
|  | 24 | +
 | 
|  | 25 | +<section class="intro"> | 
|  | 26 | + | 
|  | 27 | +</section> | 
|  | 28 | + | 
|  | 29 | +<!-- /.intro --> | 
|  | 30 | + | 
|  | 31 | +<section class="usage"> | 
|  | 32 | + | 
|  | 33 | +## Usage | 
|  | 34 | + | 
|  | 35 | +```javascript | 
|  | 36 | +var sger = require( '@stdlib/blas/base/sger' ); | 
|  | 37 | +``` | 
|  | 38 | + | 
|  | 39 | +#### sger( order, M, N, α, x, sx, y, sy, A, lda ) | 
|  | 40 | + | 
|  | 41 | +Performs the rank 1 operation `A = α*x*y^T + A`, where `α` is a scalar, `x` is an `M` element vector, `y` is an `N` element vector, and `A` is an `M` by `N` matrix. | 
|  | 42 | + | 
|  | 43 | +```javascript | 
|  | 44 | +var Float32Array = require( '@stdlib/array/float32' ); | 
|  | 45 | + | 
|  | 46 | +var A = new Float32Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] ); | 
|  | 47 | +var x = new Float32Array( [ 1.0, 1.0 ] ); | 
|  | 48 | +var y = new Float32Array( [ 1.0, 1.0, 1.0 ] ); | 
|  | 49 | + | 
|  | 50 | +sger( 'row-major', 2, 3, 1.0, x, 1, y, 1, A, 3 ); | 
|  | 51 | +// A => <Float32Array>[ 2.0, 3.0, 4.0, 5.0, 6.0, 7.0 ] | 
|  | 52 | +``` | 
|  | 53 | + | 
|  | 54 | +The function has the following parameters: | 
|  | 55 | + | 
|  | 56 | +- **order**: storage layout. | 
|  | 57 | +- **M**: number of rows in the matrix `A`. | 
|  | 58 | +- **N**: number of columns in the matrix `A`. | 
|  | 59 | +- **α**: scalar constant. | 
|  | 60 | +- **x**: an `M` element [`Float32Array`][mdn-float32array]. | 
|  | 61 | +- **sx**: stride length for `x`. | 
|  | 62 | +- **y**: an `N` element [`Float32Array`][mdn-float32array]. | 
|  | 63 | +- **sy**: stride length for `y`. | 
|  | 64 | +- **A**: input matrix stored in linear memory as a [`Float32Array`][mdn-float32array]. | 
|  | 65 | +- **lda**: stride of the first dimension of `A` (leading dimension of `A`). | 
|  | 66 | + | 
|  | 67 | +The stride parameters determine which elements in the strided arrays are accessed at runtime. For example, to iterate over every other element in `x` and `y`, | 
|  | 68 | + | 
|  | 69 | +```javascript | 
|  | 70 | +var Float32Array = require( '@stdlib/array/float32' ); | 
|  | 71 | + | 
|  | 72 | +var A = new Float32Array( [ 1.0, 4.0, 2.0, 5.0, 3.0, 6.0 ] ); | 
|  | 73 | +var x = new Float32Array( [ 1.0, 0.0, 1.0, 0.0 ] ); | 
|  | 74 | +var y = new Float32Array( [ 1.0, 0.0, 1.0, 0.0, 1.0, 0.0 ] ); | 
|  | 75 | + | 
|  | 76 | +sger( 'column-major', 2, 3, 1.0, x, 2, y, 2, A, 2 ); | 
|  | 77 | +// A => <Float32Array>[ 2.0, 5.0, 3.0, 6.0, 4.0, 7.0 ] | 
|  | 78 | +``` | 
|  | 79 | + | 
|  | 80 | +Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views. | 
|  | 81 | + | 
|  | 82 | +<!-- eslint-disable stdlib/capitalized-comments --> | 
|  | 83 | + | 
|  | 84 | +```javascript | 
|  | 85 | +var Float32Array = require( '@stdlib/array/float32' ); | 
|  | 86 | + | 
|  | 87 | +// Initial arrays... | 
|  | 88 | +var x0 = new Float32Array( [ 0.0, 1.0, 1.0 ] ); | 
|  | 89 | +var y0 = new Float32Array( [ 0.0, 1.0, 1.0, 1.0 ] ); | 
|  | 90 | +var A = new Float32Array( [ 1.0, 4.0, 2.0, 5.0, 3.0, 6.0 ] ); | 
|  | 91 | + | 
|  | 92 | +// Create offset views... | 
|  | 93 | +var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element | 
|  | 94 | +var y1 = new Float32Array( y0.buffer, y0.BYTES_PER_ELEMENT*1 ); // start at 2nd element | 
|  | 95 | + | 
|  | 96 | +sger( 'column-major', 2, 3, 1.0, x1, -1, y1, -1, A, 2 ); | 
|  | 97 | +// A => <Float32Array>[ 2.0, 5.0, 3.0, 6.0, 4.0, 7.0 ] | 
|  | 98 | +``` | 
|  | 99 | + | 
|  | 100 | +#### sger.ndarray( M, N, α, x, sx, ox, y, sy, oy, A, sa1, sa2, oa ) | 
|  | 101 | + | 
|  | 102 | +Performs the rank 1 operation `A = α*x*y^T + A`, using alternative indexing semantics and where `α` is a scalar, `x` is an `M` element vector, `y` is an `N` element vector, and `A` is an `M` by `N` matrix. | 
|  | 103 | + | 
|  | 104 | +```javascript | 
|  | 105 | +var Float32Array = require( '@stdlib/array/float32' ); | 
|  | 106 | + | 
|  | 107 | +var A = new Float32Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] ); | 
|  | 108 | +var x = new Float32Array( [ 1.0, 1.0 ] ); | 
|  | 109 | +var y = new Float32Array( [ 1.0, 1.0, 1.0 ] ); | 
|  | 110 | + | 
|  | 111 | +sger.ndarray( 2, 3, 1.0, x, 1, 0, y, 1, 0, A, 3, 1, 0 ); | 
|  | 112 | +// A => <Float32Array>[ 2.0, 3.0, 4.0, 5.0, 6.0, 7.0 ] | 
|  | 113 | +``` | 
|  | 114 | + | 
|  | 115 | +The function has the following additional parameters: | 
|  | 116 | + | 
|  | 117 | +- **sa1**: stride of the first dimension of `A`. | 
|  | 118 | +- **sa2**: stride of the second dimension of `A`. | 
|  | 119 | +- **oa**: starting index for `A`. | 
|  | 120 | +- **ox**: starting index for `x`. | 
|  | 121 | +- **oy**: starting index for `y`. | 
|  | 122 | + | 
|  | 123 | +While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying buffer, the offset parameters support indexing semantics based on starting indices. For example, | 
|  | 124 | + | 
|  | 125 | +```javascript | 
|  | 126 | +var Float32Array = require( '@stdlib/array/float32' ); | 
|  | 127 | + | 
|  | 128 | +var A = new Float32Array( [ 0.0, 0.0, 1.0, 4.0, 2.0, 5.0, 3.0, 6.0 ] ); | 
|  | 129 | +var x = new Float32Array( [ 0.0, 1.0, 0.0, 1.0, 0.0 ] ); | 
|  | 130 | +var y = new Float32Array( [ 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0 ] ); | 
|  | 131 | + | 
|  | 132 | +sger.ndarray( 2, 3, 1.0, x, 2, 1, y, 2, 1, A, 1, 2, 2 ); | 
|  | 133 | +// A => <Float32Array>[ 0.0, 0.0, 2.0, 5.0, 3.0, 6.0, 4.0, 7.0 ] | 
|  | 134 | +``` | 
|  | 135 | + | 
|  | 136 | +</section> | 
|  | 137 | + | 
|  | 138 | +<!-- /.usage --> | 
|  | 139 | + | 
|  | 140 | +<section class="notes"> | 
|  | 141 | + | 
|  | 142 | +## Notes | 
|  | 143 | + | 
|  | 144 | +- `sger()` corresponds to the [BLAS][blas] level 2 function [`sger`][blas-sger]. | 
|  | 145 | + | 
|  | 146 | +</section> | 
|  | 147 | + | 
|  | 148 | +<!-- /.notes --> | 
|  | 149 | + | 
|  | 150 | +<section class="examples"> | 
|  | 151 | + | 
|  | 152 | +## Examples | 
|  | 153 | + | 
|  | 154 | +<!-- eslint no-undef: "error" --> | 
|  | 155 | + | 
|  | 156 | +```javascript | 
|  | 157 | +var discreteUniform = require( '@stdlib/random/array/discrete-uniform' ); | 
|  | 158 | +var sger = require( '@stdlib/blas/base/sger' ); | 
|  | 159 | + | 
|  | 160 | +var opts = { | 
|  | 161 | + 'dtype': 'float32' | 
|  | 162 | +}; | 
|  | 163 | + | 
|  | 164 | +var M = 3; | 
|  | 165 | +var N = 5; | 
|  | 166 | + | 
|  | 167 | +var A = discreteUniform( M*N, 0, 255, opts ); | 
|  | 168 | +var x = discreteUniform( M, 0, 255, opts ); | 
|  | 169 | +var y = discreteUniform( N, 0, 255, opts ); | 
|  | 170 | + | 
|  | 171 | +sger( 'row-major', M, N, 1.0, x, 1, y, 1, A, N ); | 
|  | 172 | +console.log( A ); | 
|  | 173 | + | 
|  | 174 | +sger.ndarray( M, N, 1.0, x, 1, 0, y, 1, 0, A, 1, M, 0 ); | 
|  | 175 | +console.log( A ); | 
|  | 176 | + | 
|  | 177 | +``` | 
|  | 178 | + | 
|  | 179 | +</section> | 
|  | 180 | + | 
|  | 181 | +<!-- /.examples --> | 
|  | 182 | + | 
|  | 183 | +<!-- C interface documentation. --> | 
|  | 184 | + | 
|  | 185 | +* * * | 
|  | 186 | + | 
|  | 187 | +<section class="c"> | 
|  | 188 | + | 
|  | 189 | +## C APIs | 
|  | 190 | + | 
|  | 191 | +<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. --> | 
|  | 192 | + | 
|  | 193 | +<section class="intro"> | 
|  | 194 | + | 
|  | 195 | +</section> | 
|  | 196 | + | 
|  | 197 | +<!-- /.intro --> | 
|  | 198 | + | 
|  | 199 | +<!-- C usage documentation. --> | 
|  | 200 | + | 
|  | 201 | +<section class="usage"> | 
|  | 202 | + | 
|  | 203 | +### Usage | 
|  | 204 | + | 
|  | 205 | +```c | 
|  | 206 | +#include "stdlib/blas/base/sger.h" | 
|  | 207 | +``` | 
|  | 208 | + | 
|  | 209 | +#### c_sger( layout, M, N, alpha, \*X, strideX, \*Y, strideY, \*A, LDA ) | 
|  | 210 | + | 
|  | 211 | +Performs the rank 1 operation `A = alpha*x*y^T + A`, where `alpha` is a scalar, `X` is an `M` element vector, `Y` is an `N` element vector, and `A` is an `M`-by-`N` matrix. | 
|  | 212 | + | 
|  | 213 | +```c | 
|  | 214 | +#include "stdlib/blas/base/shared.h" | 
|  | 215 | + | 
|  | 216 | +float A[ 3*4 ] = { | 
|  | 217 | + 0.0f, 0.0f, 0.0f, 0.0f, | 
|  | 218 | + 0.0f, 0.0f, 0.0f, 0.0f, | 
|  | 219 | + 0.0f, 0.0f, 0.0f, 0.0f | 
|  | 220 | +}; | 
|  | 221 | + | 
|  | 222 | +const float x[ 3 ] = { 1.0f, 4.0f, 0.0f }; | 
|  | 223 | +const float y[ 4 ] = { 0.0f, 1.0f, 2.0f, 3.0f }; | 
|  | 224 | + | 
|  | 225 | +c_sger( CblasRowMajor, 3, 4, 1.0f, x, 1, y, 1, A, 4 ); | 
|  | 226 | +``` | 
|  | 227 | +
 | 
|  | 228 | +The function accepts the following arguments: | 
|  | 229 | +
 | 
|  | 230 | +- **layout**: `[in] CBLAS_LAYOUT` storage layout. | 
|  | 231 | +- **M**: `[in] CBLAS_INT` number of rows in the matrix `A`. | 
|  | 232 | +- **N**: `[in] CBLAS_INT` number of columns in the matrix `A`. | 
|  | 233 | +- **alpha**: `[in] float` scalar constant. | 
|  | 234 | +- **X**: `[in] float*` an `M` element vector. | 
|  | 235 | +- **strideX**: `[in] CBLAS_INT` stride length for `X`. | 
|  | 236 | +- **Y**: `[in] float*` an `N` element vector. | 
|  | 237 | +- **strideY**: `[in] CBLAS_INT` stride length for `Y`. | 
|  | 238 | +- **A**: `[inout] float*` input matrix. | 
|  | 239 | +- **LDA**: `[in] CBLAS_INT` stride of the first dimension of `A` (a.k.a., leading dimension of the matrix `A`). | 
|  | 240 | +
 | 
|  | 241 | +```c | 
|  | 242 | +void c_sger( const CBLAS_LAYOUT layout, const CBLAS_INT M, const CBLAS_INT N, const float alpha, const float *X, const CBLAS_INT strideX, const float *Y, const CBLAS_INT strideY, float *A, const CBLAS_INT LDA ); | 
|  | 243 | +``` | 
|  | 244 | + | 
|  | 245 | +#### c_sger_ndarray( M, N, alpha, \*X, sx, ox, \*Y, sy, oy, \*A, sa1, sa2, oa ) | 
|  | 246 | + | 
|  | 247 | +Performs the rank 1 operation `A = alpha*x*y^T + A`, using alternative indexing semantics and where `alpha` is a scalar, `X` is an `M` element vector, `Y` is an `N` element vector, and `A` is an `M`-by-`N` matrix. | 
|  | 248 | + | 
|  | 249 | +```c | 
|  | 250 | +#include "stdlib/blas/base/shared.h" | 
|  | 251 | + | 
|  | 252 | +float A[ 3*4 ] = { | 
|  | 253 | + 0.0f, 0.0f, 0.0f, 0.0f, | 
|  | 254 | + 0.0f, 0.0f, 0.0f, 0.0f, | 
|  | 255 | + 0.0f, 0.0f, 0.0f, 0.0f | 
|  | 256 | +}; | 
|  | 257 | + | 
|  | 258 | +const float x[ 3 ] = { 1.0f, 4.0f, 0.0f }; | 
|  | 259 | +const float y[ 4 ] = { 0.0f, 1.0f, 2.0f, 3.0f }; | 
|  | 260 | + | 
|  | 261 | +c_sger_ndarray( 3, 4, 1.0f, x, 1, 0, y, 1, 0, A, 4, 1, 0 ); | 
|  | 262 | +``` | 
|  | 263 | +
 | 
|  | 264 | +The function accepts the following arguments: | 
|  | 265 | +
 | 
|  | 266 | +- **layout**: `[in] CBLAS_LAYOUT` storage layout. | 
|  | 267 | +- **M**: `[in] CBLAS_INT` number of rows in the matrix `A`. | 
|  | 268 | +- **N**: `[in] CBLAS_INT` number of columns in the matrix `A`. | 
|  | 269 | +- **alpha**: `[in] float` scalar constant. | 
|  | 270 | +- **X**: `[in] float*` an `M` element vector. | 
|  | 271 | +- **sx**: `[in] CBLAS_INT` stride length for `X`. | 
|  | 272 | +- **ox**: `[in] CBLAS_INT` starting index for `X`. | 
|  | 273 | +- **Y**: `[in] float*` an `N` element vector. | 
|  | 274 | +- **sy**: `[in] CBLAS_INT` stride length for `Y`. | 
|  | 275 | +- **oy**: `[in] CBLAS_INT` starting index for `Y`. | 
|  | 276 | +- **A**: `[inout] float*` input matrix. | 
|  | 277 | +- **sa1**: `[in] CBLAS_INT` stride of the first dimension of `A`. | 
|  | 278 | +- **sa2**: `[in] CBLAS_INT` stride of the second dimension of `A`. | 
|  | 279 | +- **oa**: `[in] CBLAS_INT` starting index for `A`. | 
|  | 280 | +
 | 
|  | 281 | +```c | 
|  | 282 | +void c_sger( onst CBLAS_INT M, const CBLAS_INT N, const float alpha, const float *X, const CBLAS_INT strideX, const CBLAS_INT offsetX, const float *Y, const CBLAS_INT strideY, const CBLAS_INT offsetY, float *A, const CBLAS_INT strideA1, const CBLAS_INT strideA2, const CBLAS_INT offsetA ); | 
|  | 283 | +``` | 
|  | 284 | + | 
|  | 285 | +</section> | 
|  | 286 | + | 
|  | 287 | +<!-- /.usage --> | 
|  | 288 | + | 
|  | 289 | +<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. --> | 
|  | 290 | + | 
|  | 291 | +<section class="notes"> | 
|  | 292 | + | 
|  | 293 | +</section> | 
|  | 294 | + | 
|  | 295 | +<!-- /.notes --> | 
|  | 296 | + | 
|  | 297 | +<!-- C API usage examples. --> | 
|  | 298 | + | 
|  | 299 | +<section class="examples"> | 
|  | 300 | + | 
|  | 301 | +### Examples | 
|  | 302 | + | 
|  | 303 | +```c | 
|  | 304 | +#include "stdlib/blas/base/sger.h" | 
|  | 305 | +#include "stdlib/blas/base/shared.h" | 
|  | 306 | +#include <stdio.h> | 
|  | 307 | + | 
|  | 308 | +int main( void ) { | 
|  | 309 | + // Define a 3x4 matrix stored in row-major order: | 
|  | 310 | + float A[ 3*4 ] = { | 
|  | 311 | + 0.0f, 0.0f, 0.0f, 0.0f, | 
|  | 312 | + 0.0f, 0.0f, 0.0f, 0.0f, | 
|  | 313 | + 0.0f, 0.0f, 0.0f, 0.0f | 
|  | 314 | + }; | 
|  | 315 | + // Define `x` and `y^T` vectors: | 
|  | 316 | + const float x[ 3 ] = { 1.0f, 4.0f, 0.0f }; // M | 
|  | 317 | + const float y[ 4 ] = { 0.0f, 1.0f, 2.0f, 3.0f }; // N | 
|  | 318 | + | 
|  | 319 | + // Specify the number of rows and columns: | 
|  | 320 | + const int M = 3; | 
|  | 321 | + const int N = 4; | 
|  | 322 | + | 
|  | 323 | + // Specify stride lengths: | 
|  | 324 | + const int strideX = 1; | 
|  | 325 | + const int strideY = 1; | 
|  | 326 | + | 
|  | 327 | + // Perform operation: | 
|  | 328 | + c_sger( CblasRowMajor, M, N, 1.0f, x, strideX, y, strideY, A, N ); | 
|  | 329 | + | 
|  | 330 | + // Print the result: | 
|  | 331 | + for ( int i = 0; i < M; i++ ) { | 
|  | 332 | + for ( int j = 0; j < N; j++ ) { | 
|  | 333 | + printf( "A[%i,%i] = %f\n", i, j, A[ (i*N)+j ] ); | 
|  | 334 | + } | 
|  | 335 | + } | 
|  | 336 | + | 
|  | 337 | + // Perform operation using alterntive indexing semantics: | 
|  | 338 | + c_sger( CblasRowMajor, M, N, 1.0f, x, strideX, 0, y, 0, strideY, A, N, 1, 0 ); | 
|  | 339 | + | 
|  | 340 | + // Print the result: | 
|  | 341 | + for ( int i = 0; i < M; i++ ) { | 
|  | 342 | + for ( int j = 0; j < N; j++ ) { | 
|  | 343 | + printf( "A[%i,%i] = %f\n", i, j, A[ (i*N)+j ] ); | 
|  | 344 | + } | 
|  | 345 | + } | 
|  | 346 | +} | 
|  | 347 | +``` | 
|  | 348 | +
 | 
|  | 349 | +</section> | 
|  | 350 | +
 | 
|  | 351 | +<!-- /.examples --> | 
|  | 352 | +
 | 
|  | 353 | +</section> | 
|  | 354 | +
 | 
|  | 355 | +<!-- /.c --> | 
|  | 356 | +
 | 
|  | 357 | +<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. --> | 
|  | 358 | +
 | 
|  | 359 | +<section class="related"> | 
|  | 360 | +
 | 
|  | 361 | +</section> | 
|  | 362 | +
 | 
|  | 363 | +<!-- /.related --> | 
|  | 364 | +
 | 
|  | 365 | +<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. --> | 
|  | 366 | +
 | 
|  | 367 | +<section class="links"> | 
|  | 368 | +
 | 
|  | 369 | +[blas]: http://www.netlib.org/blas | 
|  | 370 | +
 | 
|  | 371 | +[blas-sger]: https://www.netlib.org/lapack/explore-html/d8/d75/group__ger_ga95baec6bb0a84393d7bc67212b566ab0.html | 
|  | 372 | +
 | 
|  | 373 | +[mdn-float32array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Float32Array | 
|  | 374 | +
 | 
|  | 375 | +[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray | 
|  | 376 | +
 | 
|  | 377 | +</section> | 
|  | 378 | +
 | 
|  | 379 | +<!-- /.links --> | 
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