@stdlib/stats-incr-midrange NPM

incrmidrange

Compute a mid-range incrementally.

The mid-range, or mid-extreme, is the arithmetic mean of maximum and minimum values. Accordingly, the mid-range is the midpoint of the range and a measure of central tendency.

Installation

npm install @stdlib/stats-incr-midrange

Usage

var incrmidrange = require( '@stdlib/stats-incr-midrange' );

incrmidrange()

Returns an accumulator function which incrementally computes a mid-range.

var accumulator = incrmidrange();

accumulator( [x] )

If provided an input value x, the accumulator function returns an updated mid-range. If not provided an input value x, the accumulator function returns the current mid-range.

var accumulator = incrmidrange();

var midrange = accumulator();
// returns null

midrange = accumulator( -2.0 );
// returns -2.0

midrange = accumulator( 1.0 );
// returns -0.5

midrange = accumulator( 3.0 );
// returns 0.5

midrange = accumulator();
// returns 0.5

Notes

Input values are not type checked. If provided NaN, the accumulated value is NaN for all future invocations. If non-numeric inputs are possible, you are advised to type check and handle accordingly before passing the value to the accumulator function.

Examples

var randu = require( '@stdlib/random-base-randu' );
var incrmidrange = require( '@stdlib/stats-incr-midrange' );

var accumulator;
var v;
var i;

// Initialize an accumulator:
accumulator = incrmidrange();

// For each simulated datum, update the mid-range...
for ( i = 0; i < 100; i++ ) {
    v = randu() * 100.0;
    accumulator( v );
}
console.log( accumulator() );

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.