diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/README.md b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/README.md new file mode 100644 index 000000000000..d259efb76681 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/README.md @@ -0,0 +1,126 @@ + + +# snanstdev + +> Compute the standard deviation of a one-dimensional single-precision floating-point ndarray, ignoring `NaN` values. + +
+ +This package provides an ndarray interface for computing the standard deviation of a one-dimensional +single-precision floating-point ndarray while ignoring `NaN` values. + +
+ + + +
+ +## Usage + +```javascript +var snanstdev = require( '@stdlib/stats/base/ndarray/snanstdev' ); +``` + +#### snanstdev( arrays ) + +Computes the standard deviation of a one-dimensional single-precision floating-point ndarray, ignoring NaN values. + +```javascript +var Float32Array = require( '@stdlib/array/float32' ); +var ndarray = require( '@stdlib/ndarray/base/ctor' ); + +var xbuf = new Float32Array( [ 1.0, 3.0, NaN, 2.0 ] ); +var x = new ndarray( 'float32', xbuf, [ 4 ], [ 1 ], 0, 'row-major' ); + +var c = new ndarray( 'generic', [ 1 ], [], [ 0 ], 0, 'row-major' ); + +var v = snanstdev( [ x, c ] ); +// returns ~1.0 +``` + +The function has the following parameters: + +- **arrays**: array-like object containing: + - a one-dimensional input ndarray + - a zero-dimensional ndarray specifying a degrees of freedom adjustment + +
+ + + +
+ +## Notes + +- If provided an empty one-dimensional ndarray, the function returns `NaN`. + +
+ + + +
+ +## Examples + + + +```javascript +var uniform = require( '@stdlib/random/base/uniform' ); +var filledarrayBy = require( '@stdlib/array/filled-by' ); +var bernoulli = require( '@stdlib/random/base/bernoulli' ); +var ndarray = require( '@stdlib/ndarray/base/ctor' ); +var snanstdev = require( '@stdlib/stats/base/ndarray/snanstdev' ); + +function rand() { + if ( bernoulli( 0.8 ) < 1 ) { + return NaN; + } + return uniform( -50.0, 50.0 ); +} + +var xbuf = filledarrayBy( 10, 'float32', rand ); +var x = new ndarray( 'float32', xbuf, [ xbuf.length ], [ 1 ], 0, 'row-major' ); + +var c = new ndarray( 'generic', [ 1 ], [], [ 0 ], 0, 'row-major' ); + +var v = snanstdev( [ x, c ] ); +console.log( v ); +``` + +
+ + + + + + + + + + + + + + diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/benchmark/benchmark.js b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/benchmark/benchmark.js new file mode 100644 index 000000000000..90cc86d23da0 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/benchmark/benchmark.js @@ -0,0 +1,114 @@ +/** +* @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 bench = require( '@stdlib/bench' ); +var uniform = require( '@stdlib/random/array/uniform' ); +var isnanf = require( '@stdlib/math/base/assert/is-nanf' ); +var pow = require( '@stdlib/math/base/special/pow' ); +var ndarray = require( '@stdlib/ndarray/base/ctor' ); +var scalar2ndarray = require( '@stdlib/ndarray/from-scalar' ); +var format = require( '@stdlib/string/format' ); +var pkg = require( './../package.json' ).name; +var snanstdev = require( './../lib' ); + + +// VARIABLES // + +var options = { + 'dtype': 'float32' +}; + + +// FUNCTIONS // + +/** +* Creates a benchmark function. +* +* @private +* @param {PositiveInteger} len - array length +* @returns {Function} benchmark function +*/ +function createBenchmark( len ) { + var correction; + var xbuf; + var x; + + xbuf = uniform( len, -10.0, 10.0, options ); + x = new ndarray( options.dtype, xbuf, [ len ], [ 1 ], 0, 'row-major' ); + correction = scalar2ndarray( 1.0, options ); + + return benchmark; + + /** + * Runs a benchmark. + * + * @private + * @param {Benchmark} b - benchmark instance + */ + function benchmark( b ) { + var v; + var i; + + b.tic(); + for ( i = 0; i < b.iterations; i++ ) { + v = snanstdev( [ x, correction ] ); + if ( isnanf( v ) ) { + b.fail( 'should not return NaN' ); + } + } + b.toc(); + + if ( isnanf( v ) ) { + b.fail( 'should not return NaN' ); + } + + b.pass( 'benchmark finished' ); + b.end(); + } +} + + +// MAIN // + +/** +* Main execution sequence. +* +* @private +*/ +function main() { + var len; + var min; + var max; + var f; + var i; + + min = 1; // 10^min + max = 6; // 10^max + + for ( i = min; i <= max; i++ ) { + len = pow( 10, i ); + f = createBenchmark( len ); + bench( format( '%s:len=%d', pkg, len ), f ); + } +} + +main(); diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/img/equation_arithmetic_mean.svg b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/img/equation_arithmetic_mean.svg new file mode 100644 index 000000000000..c31439606fb6 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/img/equation_arithmetic_mean.svg @@ -0,0 +1,42 @@ + +mu equals StartFraction 1 Over n EndFraction sigma-summation Underscript i equals 0 Overscript n minus 1 Endscripts x Subscript i + + + \ No newline at end of file diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/repl.txt b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/repl.txt new file mode 100644 index 000000000000..a4b416c0f288 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/repl.txt @@ -0,0 +1,55 @@ + +{{alias}}( arrays ) + Computes the standard deviation of a one-dimensional single-precision + floating-point ndarray, ignoring `NaN` values. + + If provided an empty one-dimensional ndarray, the function returns `NaN`. + + If the number of non-NaN elements minus the degrees of freedom adjustment + is less than or equal to `0`, the function returns `NaN`. + + Parameters + ---------- + arrays: ArrayLikeObject + Array-like object containing two elements: a one-dimensional input + ndarray and a zero-dimensional ndarray specifying the degrees of + freedom adjustment. Providing a non-zero degrees of freedom adjustment + has the effect of adjusting the divisor during the calculation of the + standard deviation according to `N-c`, where `N` is the number of + non-NaN elements in the input ndarray and `c` corresponds to the + provided degrees of freedom adjustment. When computing the standard + deviation of a population, setting this parameter to `0` is the + standard choice. When computing the corrected sample standard deviation, + setting this parameter to `1` is the standard choice (commonly referred + to as Bessel's correction). + + Returns + ------- + out: number + The standard deviation. + + Examples + -------- + // Create input ndarray: + > var xbuf = new {{alias:@stdlib/array/float32}}( + ... [ 1.0, -2.0, NaN, 2.0 ] + ... ); + > var dt = 'float32'; + > var sh = [ xbuf.length ]; + > var st = [ 1 ]; + > var oo = 0; + > var ord = 'row-major'; + > var x = new {{alias:@stdlib/ndarray/ctor}}( dt, xbuf, sh, st, oo, ord ); + + // Create correction ndarray: + > var opts = { 'dtype': dt }; + > var correction = + ... {{alias:@stdlib/ndarray/from-scalar}}( 1.0, opts ); + + // Compute the standard deviation: + > {{alias}}( [ x, correction ] ) + ~2.0817 + + See Also + -------- + diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/types/index.d.ts b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/types/index.d.ts new file mode 100644 index 000000000000..1601119d8466 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/types/index.d.ts @@ -0,0 +1,49 @@ +/* +* @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. +*/ + +// TypeScript Version: 4.1 + +/// + +import { float32ndarray, ndarray } from '@stdlib/types/ndarray'; + +/** +* Computes the standard deviation of a one-dimensional single-precision floating-point ndarray, ignoring `NaN` values. +* +* @param arrays - array-like object containing a one-dimensional input ndarray and a zero-dimensional ndarray specifying a degrees of freedom adjustment +* @returns computed standard deviation +* +* @example +* var Float32Array = require( '@stdlib/array/float32' ); +* var ndarray = require( '@stdlib/ndarray/base/ctor' ); +* +* var xbuf = new Float32Array( [ 1.0, 3.0, NaN, 2.0 ] ); +* var x = new ndarray( 'float32', xbuf, [ 4 ], [ 1 ], 0, 'row-major' ); +* +* // Degrees of freedom adjustment: +* var c = new ndarray( 'generic', [ 1 ], [], [ 0 ], 0, 'row-major' ); +* +* var v = snanstdev( [ x, c ] ); +* // returns 1.0 +*/ +declare function snanstdev( arrays: [ float32ndarray, ndarray ] ): number; + + +// EXPORTS // + +export = snanstdev; diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/types/test.ts b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/types/test.ts new file mode 100644 index 000000000000..c79106d85744 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/docs/types/test.ts @@ -0,0 +1,64 @@ +/* +* @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. +*/ + +/* eslint-disable space-in-parens */ + +import zeros = require('@stdlib/ndarray/zeros'); +import scalar2ndarray = require( '@stdlib/ndarray/from-scalar' ); +import snanstdev = require('./index'); + + +// TESTS // + +// The function returns a number... +{ + const x = zeros( [ 10 ], { + 'dtype': 'float32' + }); + const correction = scalar2ndarray( 1.0, { + 'dtype': 'float32' + }); + snanstdev( [ x, correction ] ); // $ExpectType number +} + +// The compiler throws an error if the function is provided a first argument which is not an array of ndarrays... +{ + snanstdev('10'); // $ExpectError + snanstdev(10); // $ExpectError + snanstdev(true); // $ExpectError + snanstdev(false); // $ExpectError + snanstdev(null); // $ExpectError + snanstdev(undefined); // $ExpectError + snanstdev([]); // $ExpectError + snanstdev({}); // $ExpectError + snanstdev((x: number): number => x); // $ExpectError +} + +// The compiler throws an error if the function is provided an unsupported number of arguments... +{ + const x = zeros([10], { + 'dtype': 'float32' + }); + + const correction = scalar2ndarray( 1.0, { + 'dtype': 'float32' + }); + + snanstdev(); // $ExpectError + snanstdev( [ x, correction ], 10 ); // $ExpectError +} diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/examples/index.js b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/examples/index.js new file mode 100644 index 000000000000..ad0d37184db9 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/examples/index.js @@ -0,0 +1,47 @@ +/** +* @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'; + +var uniform = require( '@stdlib/random/base/uniform' ); +var filledarrayBy = require( '@stdlib/array/filled-by' ); +var bernoulli = require( '@stdlib/random/base/bernoulli' ); +var ndarray = require( '@stdlib/ndarray/base/ctor' ); +var scalar2ndarray = require( '@stdlib/ndarray/from-scalar' ); +var ndarray2array = require( '@stdlib/ndarray/to-array' ); +var snanstdev = require( './../lib' ); + +function rand() { + if ( bernoulli( 0.8 ) < 1 ) { + return NaN; + } + return uniform( -50.0, 50.0 ); +} + +// Create input ndarray: +var xbuf = filledarrayBy( 10, 'float32', rand ); +var x = new ndarray( 'float32', xbuf, [ xbuf.length ], [ 1 ], 0, 'row-major' ); +console.log( ndarray2array( x ) ); + +var opts = { + 'dtype': 'float32' +}; +var correction = scalar2ndarray( 1.0, opts ); + +var v = snanstdev( [ x, correction ] ); +console.log( v ); diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/lib/index.js b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/lib/index.js new file mode 100644 index 000000000000..39661a8de4a8 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/lib/index.js @@ -0,0 +1,48 @@ +/** +* @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'; + +/** +* Compute the standard deviation of a one-dimensional single-precision floating-point ndarray, ignoring `NaN` values. +* +* @module @stdlib/stats/base/ndarray/snanstdev +* +* @example +* var Float32Array = require( '@stdlib/array/float32' ); +* var ndarray = require( '@stdlib/ndarray/base/ctor' ); +* var snanstdev = require( '@stdlib/stats/base/ndarray/snanstdev' ); +* +* var xbuf = new Float32Array( [ 1.0, 3.0, NaN, 2.0 ] ); +* var x = new ndarray( 'float32', xbuf, [ 4 ], [ 1 ], 0, 'row-major' ); +* +* // Degrees of freedom adjustment: +* var c = new ndarray( 'generic', [ 1 ], [], [ 0 ], 0, 'row-major' ); +* +* var v = snanstdev( [ x, c ] ); +* // returns ~1.0 +*/ + +// MODULES // + +var main = require( './main.js' ); + + +// EXPORTS // + +module.exports = main; diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/lib/main.js b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/lib/main.js new file mode 100644 index 000000000000..bf87029c50c9 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/lib/main.js @@ -0,0 +1,62 @@ +/** +* @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 ndarraylike2scalar = require( '@stdlib/ndarray/base/ndarraylike2scalar' ); +var numelDimension = require( '@stdlib/ndarray/base/numel-dimension' ); +var getStride = require( '@stdlib/ndarray/base/stride' ); +var getOffset = require( '@stdlib/ndarray/base/offset' ); +var getData = require( '@stdlib/ndarray/base/data-buffer' ); +var strided = require( '@stdlib/stats/base/snanstdevpn' ).ndarray; + + +// MAIN // + +/** +* Computes the standard deviation of a one-dimensional single-precision floating-point ndarray, ignoring `NaN` values. +* +* @param {ArrayLikeObject} arrays - array-like object containing a one-dimensional input ndarray and a zero-dimensional ndarray specifying a degrees of freedom adjustment +* @returns {number} standard deviation +* +* @example +* var Float32Array = require( '@stdlib/array/float32' ); +* var scalar2ndarray = require( '@stdlib/ndarray/from-scalar' ); +* var ndarray = require( '@stdlib/ndarray/base/ctor' ); +* +* var xbuf = new Float32Array( [ 1.0, 3.0, NaN, 2.0 ] ); +* var x = new ndarray( 'float32', xbuf, [ 4 ], [ 1 ], 0, 'row-major' ); +* +* var c = scalar2ndarray( 1.0, { 'dtype': 'float32' } ); +* +* var v = snanstdev( [ x, c ] ); +* // returns 1.0 +*/ +function snanstdev( arrays ) { + var correction = ndarraylike2scalar( arrays[ 1 ] ); + var x = arrays[ 0 ]; + + return strided( numelDimension( x, 0 ), correction, getData( x ), getStride( x, 0 ), getOffset( x ) ); // eslint-disable-line max-len +} + + +// EXPORTS // + +module.exports = snanstdev; diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/package.json b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/package.json new file mode 100644 index 000000000000..40a47a081410 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/package.json @@ -0,0 +1,63 @@ +{ + "name": "@stdlib/stats/base/ndarray/snanstdev", + "version": "0.0.0", + "description": "Compute the standard deviation of a one-dimensional single-precision floating-point ndarray, ignoring `NaN` values.", + "license": "Apache-2.0", + "author": { + "name": "The Stdlib Authors", + "url": "https://github.com/stdlib-js/stdlib/graphs/contributors" + }, + "contributors": [ + { + "name": "The Stdlib Authors", + "url": "https://github.com/stdlib-js/stdlib/graphs/contributors" + } + ], + "main": "./lib", + "directories": { + "benchmark": "./benchmark", + "doc": "./docs", + "example": "./examples", + "lib": "./lib", + "test": "./test" + }, + "types": "./docs/types", + "scripts": {}, + "homepage": "https://github.com/stdlib-js/stdlib", + "repository": { + "type": "git", + "url": "git://github.com/stdlib-js/stdlib.git" + }, + "bugs": { + "url": "https://github.com/stdlib-js/stdlib/issues" + }, + "dependencies": {}, + "devDependencies": {}, + "engines": { + "node": ">=0.10.0", + "npm": ">2.7.0" + }, + "os": [ + "aix", + "darwin", + "freebsd", + "linux", + "macos", + "openbsd", + "sunos", + "win32", + "windows" + ], + "keywords": [ + "stdlib", + "stdmath", + "statistics", + "stats", + "mathematics", + "math", + "standard deviation", + "dispersion", + "ndarray" + ], + "__stdlib__": {} +} diff --git a/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/test/test.js b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/test/test.js new file mode 100644 index 000000000000..b95e4fe6d096 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/base/ndarray/snanstdev/test/test.js @@ -0,0 +1,147 @@ +/** +* @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 tape = require( 'tape' ); +var isnanf = require( '@stdlib/math/base/assert/is-nanf' ); +var Float32Array = require( '@stdlib/array/float32' ); +var ndarray = require( '@stdlib/ndarray/base/ctor' ); +var scalar2ndarray = require( '@stdlib/ndarray/from-scalar' ); +var snanstdev = require( './../lib' ); + + +// VARIABLES // + +var opts = { + 'dtype': 'float32' +}; + +var correction = scalar2ndarray( 1.0, opts ); + + +// FUNCTIONS // + +/** +* Returns a one-dimensional ndarray. +* +* @private +* @param {Collection} buffer - underlying data buffer +* @param {NonNegativeInteger} length - number of indexed elements +* @param {integer} stride - stride length +* @param {NonNegativeInteger} offset - index offset +* @returns {ndarray} one-dimensional ndarray +*/ +function vector( buffer, length, stride, offset ) { + return new ndarray( 'float32', buffer, [ length ], [ stride ], offset, 'row-major' ); +} + + +// TESTS // + +tape( 'main export is a function', function test( t ) { + t.ok( true, __filename ); + t.strictEqual( typeof snanstdev, 'function', 'main export is a function' ); + t.end(); +}); + +tape( 'the function has an arity of 1', function test( t ) { + t.strictEqual( snanstdev.length, 1, 'has expected arity' ); + t.end(); +}); + +tape( 'the function returns NaN for an empty ndarray', function test( t ) { + var x = new Float32Array( [] ); + var v = snanstdev( [ vector( x, 0, 1, 0 ), correction ] ); + + t.strictEqual( isnanf( v ), true, 'returns NaN' ); + t.end(); +}); + +tape( 'the function returns NaN when all values are NaN', function test( t ) { + var x = new Float32Array( [ NaN, NaN, NaN ] ); + var v = snanstdev( [ vector( x, 3, 1, 0 ), correction ] ); + + t.strictEqual( isnanf( v ), true, 'returns NaN' ); + t.end(); +}); + +tape( 'the function returns NaN when only one non-NaN value is present', function test( t ) { + var x = new Float32Array( [ NaN, 2.0, NaN ] ); + var v = snanstdev( [ vector( x, 3, 1, 0 ), correction ] ); + + t.strictEqual( isnanf( v ), true, 'returns NaN' ); + t.end(); +}); + +tape( 'the function computes the standard deviation for multiple non-NaN values', function test( t ) { + var expected = 1.0; + var x = new Float32Array( [ 1.0, 2.0, NaN, 3.0 ] ); + var v = snanstdev( [ vector( x, 4, 1, 0 ), correction ] ); + + t.strictEqual( v, expected, 'returns expected value' ); + t.end(); +}); + +tape( 'the function supports non-unit strides', function test( t ) { + var expected = 1.0; + var x = new Float32Array([ + 1.0, // 0 + NaN, + 2.0, // 1 + NaN, + 3.0 // 2 + ]); + + var v = snanstdev( [ vector( x, 3, 2, 0 ), correction ] ); + t.strictEqual( v, expected, 'returns expected value' ); + t.end(); +}); + +tape( 'the function supports negative strides', function test( t ) { + var expected = 1.0; + var x = new Float32Array([ + 3.0, // 2 + NaN, + 2.0, // 1 + NaN, + 1.0 // 0 + ]); + + var v = snanstdev( [ vector( x, 3, -2, 4 ), correction ] ); + t.strictEqual( v, expected, 'returns expected value' ); + t.end(); +}); + +tape( 'the function supports non-zero offsets', function test( t ) { + var expected = 1.0; + var x = new Float32Array([ + NaN, + 1.0, // 0 + NaN, + 2.0, // 1 + NaN, + 3.0 // 2 + ]); + + var v = snanstdev( [ vector( x, 3, 2, 1 ), correction ] ); + t.strictEqual( v, expected, 'returns expected value' ); + t.end(); +});