refactor: add stats/incr/nanmmeanabs #5589

lib/node_modules/@stdlib/stats/incr/nanmmeanabs/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2025 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.
+
+-->
+
+# incrnanmmeanabs
+
+> Compute a moving [arithmetic mean][arithmetic-mean] of absolute values incrementally,  ignoring `NaN` values.
+
+<section class="intro">
+
+For a window of size `W`, the [arithmetic mean][arithmetic-mean] of absolute values is defined as
+
+<!-- <equation class="equation" label="eq:arithmetic_mean_absolute_values" align="center" raw="\bar{x} = \frac{1}{W} \sum_{i=0}^{W-1} |x_i|" alt="Equation for the arithmetic mean of absolute values."> -->
+
+```math
+\bar{x} = \frac{1}{W} \sum_{i=0}^{W-1} |x_i|
+```
+
+<!-- <div class="equation" align="center" data-raw-text="\bar{x} = \frac{1}{W} \sum_{i=0}^{W-1} |x_i|" data-equation="eq:arithmetic_mean_absolute_values">
+    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@320a89534d4f59b82d162f31e968222555dae2f7/lib/node_modules/@stdlib/stats/incr/mmeanabs/docs/img/equation_arithmetic_mean_absolute_values.svg" alt="Equation for the arithmetic mean of absolute values.">
+    <br>
+</div> -->
+
+<!-- </equation> -->
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var incrnanmmeanabs = require( '@stdlib/stats/incr/nanmmeanabs' );
+```
+
+#### incrnanmmeanabs( window )
+
+Returns an accumulator `function` which incrementally computes a moving [arithmetic mean][arithmetic-mean] of absolute values. The `window` parameter defines the number of values over which to compute the moving mean.
+
+```javascript
+var accumulator = incrnanmmeanabs( 3 );
+```
+
+#### accumulator( \[x] )
+
+If provided an input value `x`, the accumulator function returns an updated mean. If not provided an input value `x`, the accumulator function returns the current mean.
+
+```javascript
+var accumulator = incrnanmmeanabs( 3 );
+
+var mu = accumulator();
+// returns null
+
+// Fill the window...
+mu = accumulator( 2.0 ); // [2.0]
+// returns 2.0
+
+mu = accumulator( -5.0 ); // [2.0, -5.0]
+// returns 3.5
+
+mu = accumulator( NaN); // [2.0, -5.0]
+// returns 3.5
+
+mu = accumulator( 3.0 ); // [2.0, -5.0, 3.0]
+// returns ~3.33
+
+mu = accumulator( 5.0 ); // [-5.0, 3.0, 5.0]
+// returns ~4.33
+
+mu = accumulator();
+// returns ~4.33
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   Input values are **not type-checked**. If a `NaN` or any non-numeric value is provided, the accumulator will ignore the `NaN` and return the current mean.
+-   When a `NaN` is encountered, the mean remains unchanged for **at least** the next `W-1` calls, where `W` is the window size.
+-   During the initial phase, when fewer than `W` values are available, the returned mean is calculated using the available values.
+
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var randu = require( '@stdlib/random/base/randu' );
+var incrnanmmeanabs = require( '@stdlib/stats/incr/nanmmeanabs' );
+
+var accumulator;
+var mu;
+var v;
+var i;
+
+// Initialize an accumulator:
+accumulator = incrnanmmeanabs( 5 );
+
+// For each simulated datum, update the moving mean...
+console.log( '\nValue\tMean\n' );
+for ( i = 0; i < 100; i++ ) {
+    if ( randu() < 0.2 ) {
+        v = NaN;
+    } else {
+        v = ( randu()*100.0 ) - 50.0;
+    }
+    mu = accumulator( v );
+    console.log( '%d\t%d', v.toFixed( 3 ), mu.toFixed( 3 ) );
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
+
+<section class="related">
+
+* * *
+
+## See Also
+
+-   <span class="package-name">[`@stdlib/stats/incr/meanabs`][@stdlib/stats/incr/meanabs]</span><span class="delimiter">: </span><span class="description">compute an arithmetic mean of absolute values incrementally.</span>
+-   <span class="package-name">[`@stdlib/stats/incr/mmean`][@stdlib/stats/incr/mmean]</span><span class="delimiter">: </span><span class="description">compute a moving arithmetic mean incrementally.</span>
+-   <span class="package-name">[`@stdlib/stats/incr/msumabs`][@stdlib/stats/incr/msumabs]</span><span class="delimiter">: </span><span class="description">compute a moving sum of absolute values incrementally.</span>
+
+</section>
+
+<!-- /.related -->
+
+<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="links">
+
+[arithmetic-mean]: https://en.wikipedia.org/wiki/Arithmetic_mean
+
+<!-- <related-links> -->
+
+[@stdlib/stats/incr/meanabs]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/incr/meanabs
+
+[@stdlib/stats/incr/mmean]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/incr/mmean
+
+[@stdlib/stats/incr/msumabs]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/incr/msumabs
+
+<!-- </related-links> -->
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/stats/incr/nanmmeanabs/benchmark/benchmark.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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 randu = require( '@stdlib/random/base/randu' );
+var pkg = require( './../package.json' ).name;
+var incrnanmmeanabs = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var f;
+	var i;
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		f = incrnanmmeanabs( (i%5)+1 );
+		if ( typeof f !== 'function' ) {
+			b.fail( 'should return a function' );
+		}
+	}
+	b.toc();
+	if ( typeof f !== 'function' ) {
+		b.fail( 'should return a function' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});
+
+bench( pkg+'::accumulator', function benchmark( b ) {
+	var acc;
+	var v;
+	var i;
+
+	acc = incrnanmmeanabs( 5 );
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		v = acc( randu()-0.5 );
+		if ( v !== v ) {
+			b.fail( 'should not return NaN' );
+		}
+	}
+	b.toc();
+	if ( v !== v ) {
+		b.fail( 'should not return NaN' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/stats/incr/nanmmeanabs/docs/repl.txt

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+
+{{alias}}( W )
+    Returns an accumulator function which incrementally computes a moving
+    arithmetic mean of absolute values, ignoring `NaN` values.
+
+    The `W` parameter defines the number of values over which to compute the
+    moving mean.
+
+    If provided a value, the accumulator function returns an updated moving
+    mean. If not provided a value, the accumulator function returns the current
+    moving mean.
+
+    As `W` values are needed to fill the window buffer, the first `W-1` returned
+    values are calculated from smaller sample sizes. Until the window is full,
+    each returned value is calculated from all provided values.
+
+    Parameters
+    ----------
+    W: integer
+        Window size.
+
+    Returns
+    -------
+    acc: Function
+        Accumulator function.
+
+    Examples
+    --------
+    > var accumulator = {{alias}}( 3 );
+    > var mu = accumulator()
+    null
+    > mu = accumulator( 2.0 )
+    2.0
+    > mu = accumulator( -5.0 )
+    3.5
+    > mu = accumulator( NaN )
+    3.5
+    > mu = accumulator( 3.0 )
+    ~3.33
+    > mu = accumulator( 5.0 )
+    ~4.33
+    > mu = accumulator()
+    ~4.33
+
+    See Also
+    --------
+