time-to-botec/squiggle/node_modules/@stdlib/stats/incr/midrange/README.md

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.

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() );