/**
* @license Apache-2.0
*
* Copyright (c) 2018 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 isPositiveInteger = require( '@stdlib/assert/is-positive-integer' ).isPrimitive;
var isnan = require( '@stdlib/math/base/assert/is-nan' );
var abs = require( '@stdlib/math/base/special/abs' );
var PINF = require( '@stdlib/constants/math/float64-pinf' );


// MAIN //

/**
* Returns an accumulator function which incrementally computes a moving minimum absolute value.
*
* @param {PositiveInteger} W - window size
* @throws {TypeError} must provide a positive integer
* @returns {Function} accumulator function
*
* @example
* var accumulator = incrmminabs( 3 );
*
* var m = accumulator();
* // returns null
*
* m = accumulator( 2.0 );
* // returns 2.0
*
* m = accumulator( -5.0 );
* // returns 2.0
*
* m = accumulator( 3.0 );
* // returns 2.0
*
* m = accumulator( 5.0 );
* // returns 2.0
*
* m = accumulator();
* // returns 2.0
*/
function incrmminabs( W ) {
	var buf;
	var min;
	var N;
	var i;
	if ( !isPositiveInteger( W ) ) {
		throw new TypeError( 'invalid input argument. Must provide a positive integer. Value: `' + W + '`.' );
	}
	buf = new Array( W );
	min = PINF;
	i = -1;
	N = 0;

	return accumulator;

	/**
	* If provided a value, the accumulator function returns an updated minimum absolute value. If not provided a value, the accumulator function returns the current minimum absolute value.
	*
	* @private
	* @param {number} [x] - input value
	* @returns {(number|null)} minimum absolute value or null
	*/
	function accumulator( x ) {
		var ax;
		var v;
		var k;
		if ( arguments.length === 0 ) {
			if ( N === 0 ) {
				return null;
			}
			return min;
		}
		// Update the index for managing the circular buffer:
		i = (i+1) % W;

		// Compute the absolute value:
		ax = abs( x );

		// Case: update initial window...
		if ( N < W ) {
			N += 1;
			if ( isnan( x ) || ax < min ) {
				min = ax;
			}
		}
		// Case: incoming value is NaN or less than current minimum value...
		else if ( isnan( x ) || ax < min ) {
			min = ax;
		}
		// Case: outgoing value is the current minimum and the new value is greater than the minimum, and, thus, we need to find a new minimum among the current values...
		else if ( ( buf[ i ] === min && ax > min ) || isnan( buf[ i ] ) ) {
			min = ax;
			for ( k = 0; k < W; k++ ) {
				if ( k !== i ) {
					v = buf[ k ];
					if ( isnan( v ) ) {
						min = v;
						break; // no need to continue searching
					}
					if ( v < min ) {
						min = v;
					}
				}
			}
		}
		// Case: updating existing window; however, the minimum absolute value does not change so nothing to do but update our buffer...
		buf[ i ] = ax;

		return min;
	}
}


// EXPORTS //

module.exports = incrmminabs;

@@ -730,66 +730,8 @@
 ve;%0A
-var isnan = require( '@stdlib/math/base/assert/is-nan' );%0A
 var 
@@ -784,20 +784,24 @@
  );%0Avar 
-PINF
+incrmmin
  = requi
@@ -817,35 +817,23 @@
 lib/
-con
 sta
-n
 ts/
-math/float64-p
+incr/mm
 in
-f
 ' );
@@ -1446,37 +1446,11 @@
 var 
-buf;%0A%09var min;%0A%09var N;%0A%09var i
+min
 ;%0A%09i
@@ -1594,60 +1594,28 @@
 %09%7D%0A%09
-buf = new Array( W );%0A%09min = PINF;%0A%09i = -1;%0A%09N = 0;%0A
+min = incrmmin( W );
 %0A%09re
@@ -1972,36 +1972,8 @@
 ) %7B%0A
-%09%09var ax;%0A%09%09var v;%0A%09%09var k;%0A
 %09%09if
@@ -2009,1072 +2009,50 @@
 %0A%09%09%09
-if ( N === 0 ) %7B%0A%09%09%09%09return null;%0A%09%09%09%7D%0A%09%09%09return min;%0A%09%09%7D%0A%09%09// Update the index for managing the circular buffer:%0A%09%09i = (i+1) %25 W;%0A%0A%09%09// Compute the absolute value:%0A%09%09ax = abs( x );%0A%0A%09%09// Case: update initial window...%0A%09%09if ( N %3C W ) %7B%0A%09%09%09N += 1;%0A%09%09%09if ( isnan( x ) %7C%7C ax %3C min ) %7B%0A%09%09%09%09min = ax;%0A%09%09%09%7D%0A%09%09%7D%0A%09%09// Case: incoming value is NaN or less than current minimum value...%0A%09%09else if ( isnan( x ) %7C%7C ax %3C min ) %7B%0A%09%09%09min = ax;%0A%09%09%7D%0A%09%09// Case: outgoing value is the current minimum and the new value is greater than the minimum, and, thus, we need to find a new minimum among the current values...%0A%09%09else if ( ( buf%5B i %5D === min && ax %3E min ) %7C%7C isnan( buf%5B i %5D ) ) %7B%0A%09%09%09min = ax;%0A%09%09%09for ( k = 0; k %3C W; k++ ) %7B%0A%09%09%09%09if ( k !== i ) %7B%0A%09%09%09%09%09v = buf%5B k %5D;%0A%09%09%09%09%09if ( isnan( v ) ) %7B%0A%09%09%09%09%09%09min = v;%0A%09%09%09%09%09%09break; // no need to continue searching%0A%09%09%09%09%09%7D%0A%09%09%09%09%09if ( v %3C min ) %7B%0A%09%09%09%09%09%09min = v;%0A%09%09%09%09%09%7D%0A%09%09%09%09%7D%0A%09%09%09%7D%0A%09%09%7D%0A%09%09// Case: updating existing window; however, the minimum absolute value does not change so nothing to do but update our buffer...%0A%09%09buf%5B i %5D = ax;%0A%0A%09%09return min
+return min();%0A%09%09%7D%0A%09%09return min( abs( x ) )
 ;%0A%09%7D

Simplify implementation