incrmeanabs

Compute an arithmetic mean of absolute values incrementally.

The arithmetic mean of absolute values is defined as

$$\mu = \frac{1}{n} \sum_{i=0}^{n-1} |x_i|$$

Usage

var incrmeanabs = require( '@stdlib/stats/incr/meanabs' );

incrmeanabs()

Returns an accumulator function which incrementally computes an arithmetic mean of absolute values.

var accumulator = incrmeanabs();

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.

var accumulator = incrmeanabs();

var mu = accumulator( 2.0 );
// returns 2.0

mu = accumulator( -1.0 );
// returns 1.5

mu = accumulator( -3.0 );
// returns 2.0

mu = accumulator();
// returns 2.0

Notes

• Input values are not type checked. If provided NaN or a value which, when used in computations, results in 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 incrmeanabs = require( '@stdlib/stats/incr/meanabs' );

var accumulator;
var v;
var i;

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

// For each simulated datum, update the mean...
for ( i = 0; i < 100; i++ ) {
    v = ( randu()*100.0 ) - 50.0;
    accumulator( v );
}
console.log( accumulator() );

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See Also

• @stdlib/stats/incr/mean: compute an arithmetic mean incrementally.
• @stdlib/stats/incr/mmeanabs: compute a moving arithmetic mean of absolute values incrementally.
• @stdlib/stats/incr/sumabs: compute a sum of absolute values incrementally.