+ 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 | 2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +15x +15x +15x +15x +15x +15x +15x +15x +15x +15x +4x +4x +15x +2x +2x +15x +1x +15x +8x +8x +9x +9x +15x +32x +32x +32x +32x +32x +9x +15x +2x +2x +2x +2x +2x + | /**
+* @license Apache-2.0
+*
+* Copyright (c) 2020 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';
+
+// MAIN //
+
+/**
+* Computes the variance of a double-precision floating-point strided array using a one-pass textbook algorithm.
+*
+* @param {PositiveInteger} N - number of indexed elements
+* @param {number} correction - degrees of freedom adjustment
+* @param {Float64Array} x - input array
+* @param {integer} stride - stride length
+* @returns {number} variance
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+*
+* var x = new Float64Array( [ 1.0, -2.0, 2.0 ] );
+* var N = x.length;
+*
+* var v = dvariancetk( N, 1, x, 1 );
+* // returns ~4.3333
+*/
+function dvariancetk( N, correction, x, stride ) {
+ var S2;
+ var ix;
+ var S;
+ var v;
+ var n;
+ var i;
+
+ n = N - correction;
+ if ( N <= 0 || n <= 0.0 ) {
+ return NaN;
+ }
+ if ( N === 1 || stride === 0 ) {
+ return 0.0;
+ }
+ if ( stride < 0 ) {
+ ix = (1-N) * stride;
+ } else {
+ ix = 0;
+ }
+ S2 = 0.0;
+ S = 0.0;
+ for ( i = 0; i < N; i++ ) {
+ v = x[ ix ];
+ S2 += v * v;
+ S += v;
+ ix += stride;
+ }
+ return (S2 - ((S/N)*S)) / n;
+}
+
+
+// EXPORTS //
+
+module.exports = dvariancetk;
+ |
+ 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 | 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 +30x +30x +30x +3x +3x +3x +3x +3x + | /**
+* @license Apache-2.0
+*
+* Copyright (c) 2020 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 addon = require( './../src/addon.node' );
+
+
+// MAIN //
+
+/**
+* Computes the variance of a double-precision floating-point strided array using a one-pass textbook algorithm.
+*
+* @param {PositiveInteger} N - number of indexed elements
+* @param {number} correction - degrees of freedom adjustment
+* @param {Float64Array} x - input array
+* @param {integer} stride - stride length
+* @returns {number} variance
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+*
+* var x = new Float64Array( [ 1.0, -2.0, 2.0 ] );
+* var N = x.length;
+*
+* var v = dvariancetk( N, 1, x, 1 );
+* // returns ~4.3333
+*/
+function dvariancetk( N, correction, x, stride ) {
+ return addon( N, correction, x, stride );
+}
+
+
+// EXPORTS //
+
+module.exports = dvariancetk;
+ |
+ Press n or j to go to the next uncovered block, b, p or k for the previous block. +
+ +| File | ++ | Statements | ++ | Branches | ++ | Functions | ++ | Lines | ++ |
|---|---|---|---|---|---|---|---|---|---|
| dvariancetk.js | +
+
+ |
+ 100% | +75/75 | +100% | +13/13 | +100% | +1/1 | +100% | +75/75 | +
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+
+ |
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+
+ |
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+
+ |
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+
+ |
+ 100% | +35/35 | +100% | +1/1 | +100% | +0/0 | +100% | +35/35 | +
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+
+ |
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+
+ |
+ 100% | +61/61 | +100% | +3/3 | +100% | +1/1 | +100% | +61/61 | +
+ 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 | 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 +3x +3x +3x +3x +3x +3x +3x +3x +3x +3x +3x +1x +3x +2x +2x +3x +3x +3x +3x +3x +3x +3x + | /**
+* @license Apache-2.0
+*
+* Copyright (c) 2020 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 variance of a double-precision floating-point strided array using a one-pass textbook algorithm.
+*
+* @module @stdlib/stats/base/dvariancetk
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+* var dvariancetk = require( '@stdlib/stats/base/dvariancetk' );
+*
+* var x = new Float64Array( [ 1.0, -2.0, 2.0 ] );
+* var N = x.length;
+*
+* var v = dvariancetk( N, 1, x, 1 );
+* // returns ~4.3333
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+* var floor = require( '@stdlib/math/base/special/floor' );
+* var dvariancetk = require( '@stdlib/stats/base/dvariancetk' );
+*
+* var x = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] );
+* var N = floor( x.length / 2 );
+*
+* var v = dvariancetk.ndarray( N, 1, x, 2, 1 );
+* // returns 6.25
+*/
+
+// MODULES //
+
+var join = require( 'path' ).join;
+var tryRequire = require( '@stdlib/utils/try-require' );
+var isError = require( '@stdlib/assert/is-error' );
+var main = require( './main.js' );
+
+
+// MAIN //
+
+var dvariancetk;
+var tmp = tryRequire( join( __dirname, './native.js' ) );
+if ( isError( tmp ) ) {
+ dvariancetk = main;
+} else {
+ dvariancetk = tmp;
+}
+
+
+// EXPORTS //
+
+module.exports = dvariancetk;
+
+// exports: { "ndarray": "dvariancetk.ndarray" }
+ |
+ 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 | 1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x + | /** +* @license Apache-2.0 +* +* Copyright (c) 2020 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 setReadOnly = require( '@stdlib/utils/define-nonenumerable-read-only-property' ); +var dvariancetk = require( './dvariancetk.js' ); +var ndarray = require( './ndarray.js' ); + + +// MAIN // + +setReadOnly( dvariancetk, 'ndarray', ndarray ); + + +// EXPORTS // + +module.exports = dvariancetk; + |
+ 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 | 1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x +1x + | /** +* @license Apache-2.0 +* +* Copyright (c) 2020 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 setReadOnly = require( '@stdlib/utils/define-nonenumerable-read-only-property' ); +var dvariancetk = require( './dvariancetk.native.js' ); +var ndarray = require( './ndarray.native.js' ); + + +// MAIN // + +setReadOnly( dvariancetk, 'ndarray', ndarray ); + + +// EXPORTS // + +module.exports = dvariancetk; + |
+ 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 | 2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +15x +15x +15x +15x +15x +15x +15x +15x +15x +15x +4x +4x +15x +2x +2x +9x +9x +9x +15x +32x +32x +32x +32x +32x +9x +15x +2x +2x +2x +2x +2x + | /**
+* @license Apache-2.0
+*
+* Copyright (c) 2020 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';
+
+// MAIN //
+
+/**
+* Computes the variance of a double-precision floating-point strided array using a one-pass textbook algorithm.
+*
+* @param {PositiveInteger} N - number of indexed elements
+* @param {number} correction - degrees of freedom adjustment
+* @param {Float64Array} x - input array
+* @param {integer} stride - stride length
+* @param {NonNegativeInteger} offset - starting index
+* @returns {number} variance
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+* var floor = require( '@stdlib/math/base/special/floor' );
+*
+* var x = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] );
+* var N = floor( x.length / 2 );
+*
+* var v = dvariancetk( N, 1, x, 2, 1 );
+* // returns 6.25
+*/
+function dvariancetk( N, correction, x, stride, offset ) {
+ var S2;
+ var ix;
+ var S;
+ var v;
+ var n;
+ var i;
+
+ n = N - correction;
+ if ( N <= 0 || n <= 0.0 ) {
+ return NaN;
+ }
+ if ( N === 1 || stride === 0 ) {
+ return 0.0;
+ }
+ ix = offset;
+ S2 = 0.0;
+ S = 0.0;
+ for ( i = 0; i < N; i++ ) {
+ v = x[ ix ];
+ S2 += v * v;
+ S += v;
+ ix += stride;
+ }
+ return (S2 - ((S/N)*S)) / n;
+}
+
+
+// EXPORTS //
+
+module.exports = dvariancetk;
+ |
+ 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 | 2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +2x +15x +15x +15x +1x +1x +15x +15x +15x +2x +2x +2x +2x +2x + | /**
+* @license Apache-2.0
+*
+* Copyright (c) 2020 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 Float64Array = require( '@stdlib/array/float64' );
+var addon = require( './dvariancetk.native.js' );
+
+
+// MAIN //
+
+/**
+* Computes the variance of a double-precision floating-point strided array using a one-pass textbook algorithm.
+*
+* @param {PositiveInteger} N - number of indexed elements
+* @param {number} correction - degrees of freedom adjustment
+* @param {Float64Array} x - input array
+* @param {integer} stride - stride length
+* @param {NonNegativeInteger} offset - starting index
+* @returns {number} variance
+*
+* @example
+* var Float64Array = require( '@stdlib/array/float64' );
+* var floor = require( '@stdlib/math/base/special/floor' );
+*
+* var x = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] );
+* var N = floor( x.length / 2 );
+*
+* var v = dvariancetk( N, 1, x, 2, 1 );
+* // returns 6.25
+*/
+function dvariancetk( N, correction, x, stride, offset ) {
+ var view;
+ if ( stride < 0 ) {
+ offset += (N-1) * stride;
+ }
+ view = new Float64Array( x.buffer, x.byteOffset+(x.BYTES_PER_ELEMENT*offset), x.length-offset ); // eslint-disable-line max-len
+ return addon( N, correction, view, stride );
+}
+
+
+// EXPORTS //
+
+module.exports = dvariancetk;
+ |