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Refactor variancetk
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+274
-110
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12 files changed

+274
-110
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‎lib/node_modules/@stdlib/stats/base/variancetk/benchmark/benchmark.js

Lines changed: 10 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -21,11 +21,18 @@
2121
// MODULES //
2222

2323
var bench = require( '@stdlib/bench' );
24-
var randu = require( '@stdlib/random/base/randu' );
24+
var uniform = require( '@stdlib/random/array/uniform' );
2525
var isnan = require( '@stdlib/math/base/assert/is-nan' );
2626
var pow = require( '@stdlib/math/base/special/pow' );
2727
var pkg = require( './../package.json' ).name;
28-
var variancetk = require( './../lib/variancetk.js' );
28+
var variancetk = require( './../lib/main.js' );
29+
30+
31+
// VARIABLES //
32+
33+
var options = {
34+
'dtype': 'generic'
35+
};
2936

3037

3138
// FUNCTIONS //
@@ -38,13 +45,7 @@ var variancetk = require( './../lib/variancetk.js' );
3845
* @returns {Function} benchmark function
3946
*/
4047
function createBenchmark( len ) {
41-
var x;
42-
var i;
43-
44-
x = [];
45-
for ( i = 0; i < len; i++ ) {
46-
x.push( ( randu()*20.0 ) - 10.0 );
47-
}
48+
var x = uniform( len, -10, 10, options );
4849
return benchmark;
4950

5051
function benchmark( b ) {

‎lib/node_modules/@stdlib/stats/base/variancetk/benchmark/benchmark.ndarray.js

Lines changed: 9 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -21,13 +21,20 @@
2121
// MODULES //
2222

2323
var bench = require( '@stdlib/bench' );
24-
var randu = require( '@stdlib/random/base/randu' );
24+
var uniform = require( '@stdlib/random/array/uniform' );
2525
var isnan = require( '@stdlib/math/base/assert/is-nan' );
2626
var pow = require( '@stdlib/math/base/special/pow' );
2727
var pkg = require( './../package.json' ).name;
2828
var variancetk = require( './../lib/ndarray.js' );
2929

3030

31+
// VARIABLES //
32+
33+
var options = {
34+
'dtype': 'generic'
35+
};
36+
37+
3138
// FUNCTIONS //
3239

3340
/**
@@ -38,13 +45,7 @@ var variancetk = require( './../lib/ndarray.js' );
3845
* @returns {Function} benchmark function
3946
*/
4047
function createBenchmark( len ) {
41-
var x;
42-
var i;
43-
44-
x = [];
45-
for ( i = 0; i < len; i++ ) {
46-
x.push( ( randu()*20.0 ) - 10.0 );
47-
}
48+
var x = uniform( len, -10, 10, options );
4849
return benchmark;
4950

5051
function benchmark( b ) {

‎lib/node_modules/@stdlib/stats/base/variancetk/docs/repl.txt

Lines changed: 14 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -1,10 +1,10 @@
11

2-
{{alias}}( N, correction, x, stride )
2+
{{alias}}( N, correction, x, strideX )
33
Computes the variance of a strided array using a one-pass textbook
44
algorithm.
55

6-
The `N` and `stride` parameters determine which elements in `x` are accessed
7-
at runtime.
6+
The `N` and stride parameters determine which elements in the strided array
7+
are accessed at runtime.
88

99
Indexing is relative to the first index. To introduce an offset, use a typed
1010
array view.
@@ -31,8 +31,8 @@
3131
x: Array<number>|TypedArray
3232
Input array.
3333

34-
stride: integer
35-
Index increment.
34+
strideX: integer
35+
Stride length.
3636

3737
Returns
3838
-------
@@ -46,22 +46,21 @@
4646
> {{alias}}( x.length, 1, x, 1 )
4747
~4.3333
4848

49-
// Using `N` and `stride` parameters:
49+
// Using `N` and stride parameters:
5050
> x = [ -2.0, 1.0, 1.0, -5.0, 2.0, -1.0 ];
51-
> var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 );
52-
> var stride = 2;
53-
> {{alias}}( N, 1, x, stride )
51+
> {{alias}}( 3, 1, x, 2 )
5452
~4.3333
5553

5654
// Using view offsets:
5755
> var x0 = new {{alias:@stdlib/array/float64}}( [ 1.0, -2.0, 3.0, 2.0, 5.0, -1.0 ] );
5856
> var x1 = new {{alias:@stdlib/array/float64}}( x0.buffer, x0.BYTES_PER_ELEMENT*1 );
5957
> N = {{alias:@stdlib/math/base/special/floor}}( x0.length / 2 );
6058
> stride = 2;
61-
> {{alias}}( N, 1, x1, stride )
59+
> {{alias}}( 3, 1, x1, 2 )
6260
~4.3333
6361

64-
{{alias}}.ndarray( N, correction, x, stride, offset )
62+
63+
{{alias}}.ndarray( N, correction, x, strideX, offsetX )
6564
Computes the variance of a strided array using a one-pass textbook algorithm
6665
and alternative indexing semantics.
6766

@@ -89,10 +88,10 @@
8988
x: Array<number>|TypedArray
9089
Input array.
9190

92-
stride: integer
93-
Index increment.
91+
strideX: integer
92+
Stride length.
9493

95-
offset: integer
94+
offsetX: integer
9695
Starting index.
9796

9897
Returns
@@ -109,8 +108,7 @@
109108

110109
// Using offset parameter:
111110
> var x = [ 1.0, -2.0, 3.0, 2.0, 5.0, -1.0 ];
112-
> var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 );
113-
> {{alias}}.ndarray( N, 1, x, 2, 1 )
111+
> {{alias}}.ndarray( 3, 1, x, 2, 1 )
114112
~4.3333
115113

116114
See Also

‎lib/node_modules/@stdlib/stats/base/variancetk/docs/types/index.d.ts

Lines changed: 11 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -20,7 +20,12 @@
2020

2121
/// <reference types="@stdlib/types"/>
2222

23-
import { NumericArray } from '@stdlib/types/array';
23+
import { NumericArray, Collection, AccessorArrayLike } from '@stdlib/types/array';
24+
25+
/**
26+
* Input array.
27+
*/
28+
type InputArray = NumericArray | Collection<number> | AccessorArrayLike<number>;
2429

2530
/**
2631
* Interface describing `variancetk`.
@@ -32,7 +37,7 @@ interface Routine {
3237
* @param N - number of indexed elements
3338
* @param correction - degrees of freedom adjustment
3439
* @param x - input array
35-
* @param stride - stride length
40+
* @param strideX - stride length
3641
* @returns variance
3742
*
3843
* @example
@@ -41,16 +46,16 @@ interface Routine {
4146
* var v = variancetk( x.length, 1, x, 1 );
4247
* // returns ~4.3333
4348
*/
44-
( N: number, correction: number, x: NumericArray, stride: number ): number;
49+
( N: number, correction: number, x: InputArray, strideX: number ): number;
4550

4651
/**
4752
* Computes the variance of a strided array using a one-pass textbook algorithm and alternative indexing semantics.
4853
*
4954
* @param N - number of indexed elements
5055
* @param correction - degrees of freedom adjustment
5156
* @param x - input array
52-
* @param stride - stride length
53-
* @param offset - starting index
57+
* @param strideX - stride length
58+
* @param offsetX - starting index
5459
* @returns variance
5560
*
5661
* @example
@@ -68,7 +73,7 @@ interface Routine {
6873
* @param N - number of indexed elements
6974
* @param correction - degrees of freedom adjustment
7075
* @param x - input array
71-
* @param stride - stride length
76+
* @param strideX - stride length
7277
* @returns variance
7378
*
7479
* @example

‎lib/node_modules/@stdlib/stats/base/variancetk/docs/types/test.ts

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -16,6 +16,7 @@
1616
* limitations under the License.
1717
*/
1818

19+
import AccessorArray = require( '@stdlib/array/base/accessor' );
1920
import variancetk = require( './index' );
2021

2122

@@ -26,6 +27,7 @@ import variancetk = require( './index' );
2627
const x = new Float64Array( 10 );
2728

2829
variancetk( x.length, 1, x, 1 ); // $ExpectType number
30+
variancetk( x.length, 1, new AccessorArray( x ), 1 ); // $ExpectType number
2931
}
3032

3133
// The compiler throws an error if the function is provided a first argument which is not a number...
@@ -101,6 +103,7 @@ import variancetk = require( './index' );
101103
const x = new Float64Array( 10 );
102104

103105
variancetk.ndarray( x.length, 1, x, 1, 0 ); // $ExpectType number
106+
variancetk.ndarray( x.length, 1, new AccessorArray( x ), 1, 0 ); // $ExpectType number
104107
}
105108

106109
// The compiler throws an error if the `ndarray` method is provided a first argument which is not a number...

‎lib/node_modules/@stdlib/stats/base/variancetk/examples/index.js

Lines changed: 4 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -18,18 +18,12 @@
1818

1919
'use strict';
2020

21-
var randu = require( '@stdlib/random/base/randu' );
22-
var round = require( '@stdlib/math/base/special/round' );
23-
var Float64Array = require( '@stdlib/array/float64' );
21+
var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
2422
var variancetk = require( './../lib' );
2523

26-
var x;
27-
var i;
28-
29-
x = new Float64Array( 10 );
30-
for ( i = 0; i < x.length; i++ ) {
31-
x[ i ] = round( (randu()*100.0) - 50.0 );
32-
}
24+
var x = discreteUniform( 10, -50, 50, {
25+
'dtype': 'float64'
26+
});
3327
console.log( x );
3428

3529
var v = variancetk( x.length, 1, x, 1 );

‎lib/node_modules/@stdlib/stats/base/variancetk/lib/variancetk.js renamed to ‎lib/node_modules/@stdlib/stats/base/variancetk/lib/accessors.js

Lines changed: 28 additions & 19 deletions
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,7 @@
11
/**
22
* @license Apache-2.0
33
*
4-
* Copyright (c) 2020 The Stdlib Authors.
4+
* Copyright (c) 2025 The Stdlib Authors.
55
*
66
* Licensed under the Apache License, Version 2.0 (the "License");
77
* you may not use this file except in compliance with the License.
@@ -23,19 +23,28 @@
2323
/**
2424
* Computes the variance of a strided array using a one-pass textbook algorithm.
2525
*
26+
* @private
2627
* @param {PositiveInteger} N - number of indexed elements
2728
* @param {number} correction - degrees of freedom adjustment
28-
* @param {NumericArray} x - input array
29-
* @param {integer} stride - stride length
29+
* @param {Object} x - input array object
30+
* @param {Collection} x.data - input array data
31+
* @param {Array<Function>} x.accessors - array element accessors
32+
* @param {integer} strideX - stride length
33+
* @param {NonNegativeInteger} offsetX - starting index
3034
* @returns {number} variance
3135
*
3236
* @example
33-
* var x = [ 1.0, -2.0, 2.0 ];
37+
* var toAccessorArray = require( '@stdlib/array/base/to-accessor-array' );
38+
* var arraylike2object = require( '@stdlib/array/base/arraylike2object' );
3439
*
35-
* var v = variancetk( x.length, 1, x, 1 );
40+
* var x = toAccessorArray( [ 1.0, -2.0, 2.0 ] );
41+
*
42+
* var v = variancetk( x.length, 1, arraylike2object( x ), 1, 1 );
3643
* // returns ~4.3333
3744
*/
38-
function variancetk( N, correction, x, stride ) {
45+
function variancetk( N, correction, x, strideX, offsetX ) {
46+
var xbuf;
47+
var get;
3948
var S2;
4049
var ix;
4150
var S;
@@ -44,24 +53,24 @@ function variancetk( N, correction, x, stride ) {
4453
var i;
4554

4655
n = N - correction;
47-
if ( N <= 0 || n <= 0.0 ) {
48-
return NaN;
49-
}
50-
if ( N === 1 || stride === 0 ) {
51-
return 0.0;
52-
}
53-
if ( stride < 0 ) {
54-
ix = (1-N) * stride;
55-
} else {
56-
ix = 0;
56+
57+
// Cache reference to array data:
58+
xbuf = x.data;
59+
60+
// Cache a reference to the element accessor:
61+
get = x.accessors[ 0 ];
62+
63+
if ( N === 1 || strideX === 0 ) {
64+
return get( xbuf, offsetX );
5765
}
58-
S2 = 0.0;
66+
ix = offsetX;
67+
S2 = get( xbuf, ix );
5968
S = 0.0;
6069
for ( i = 0; i < N; i++ ) {
61-
v = x[ ix ];
70+
v = get( xbuf, ix );
6271
S2 += v * v;
6372
S += v;
64-
ix += stride;
73+
ix += strideX;
6574
}
6675
return (S2 - ((S/N)*S)) / n;
6776
}

‎lib/node_modules/@stdlib/stats/base/variancetk/lib/index.js

Lines changed: 9 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -27,25 +27,29 @@
2727
* var variancetk = require( '@stdlib/stats/base/variancetk' );
2828
*
2929
* var x = [ 1.0, -2.0, 2.0 ];
30-
* var N = x.length;
3130
*
32-
* var v = variancetk( N, 1, x, 1 );
31+
* var v = variancetk( x.length, 1, x, 1 );
3332
* // returns ~4.3333
3433
*
3534
* @example
36-
* var floor = require( '@stdlib/math/base/special/floor' );
3735
* var variancetk = require( '@stdlib/stats/base/variancetk' );
3836
*
3937
* var x = [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ];
40-
* var N = floor( x.length / 2 );
4138
*
42-
* var v = variancetk.ndarray( N, 1, x, 2, 1 );
39+
* var v = variancetk.ndarray( 4, 1, x, 2, 1 );
4340
* // returns 6.25
4441
*/
4542

4643
// MODULES //
4744

45+
var setReadOnly = require( '@stdlib/utils/define-nonenumerable-read-only-property' );
4846
var main = require( './main.js' );
47+
var ndarray = require( './ndarray.js' );
48+
49+
50+
// MAIN //
51+
52+
setReadOnly( main, 'ndarray', ndarray );
4953

5054

5155
// EXPORTS //

‎lib/node_modules/@stdlib/stats/base/variancetk/lib/main.js

Lines changed: 20 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -20,14 +20,31 @@
2020

2121
// MODULES //
2222

23-
var setReadOnly = require( '@stdlib/utils/define-nonenumerable-read-only-property' );
24-
var variancetk = require( './variancetk.js' );
23+
var stride2offset = require( '@stdlib/strided/base/stride2offset' );
2524
var ndarray = require( './ndarray.js' );
2625

2726

2827
// MAIN //
2928

30-
setReadOnly( variancetk, 'ndarray', ndarray );
29+
/**
30+
* Computes the variance of a strided array.
31+
*
32+
* @param {PositiveInteger} N - number of indexed elements
33+
* @param {PositiveInteger} correction - degrees of freedom adjustment
34+
* @param {NumericArray} x - input array
35+
* @param {integer} strideX - stride length
36+
* @returns {number} minimum value
37+
*
38+
* @example
39+
* var x = [ 1.0, -2.0, 2.0 ];
40+
* var N = x.length;
41+
*
42+
* var v = variancetk( N, 1, x, 1 );
43+
* // returns
44+
*/
45+
function variancetk( N, correction, x, strideX ) {
46+
return ndarray( N, correction, x, strideX, stride2offset( N, strideX ) );
47+
}
3148

3249

3350
// EXPORTS //

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