Alpha Max Plus Beta Min

Compute the hypotenuse using the alpha max plus beta min algorithm.

Usage

var ampbm = require( '@stdlib/fastmath/special/alpha-max-plus-beta-min' );

ampbm( x, y )

Computes the hypotenuse using the alpha max plus beta min algorithm.

var h = ampbm( -5.0, 12.0 );
// returns ~13.5

ampbm.factory( alpha, beta, [nonnegative[, ints]] )

Returns a function for computing the hypotenuse using coefficients alpha and beta.

var hypot = ampbm.factory( 1.0, 0.5 );

var h = hypot( -5.0, 12.0 );
// returns 14.5

If the returned function should only expect nonnegative arguments, set the nonnegative argument to true.

var hypot = ampbm.factory( 1.0, 0.5, true );

var h = hypot( 5.0, 12.0 );
// returns 14.5

If the returned function should only expect signed 32-bit integers, set the ints argument to true.

var hypot = ampbm.factory( 1.0, 0.5, false, true );

var h = hypot( -5.0, 12.0 );
// returns 14

If the returned function should only expect unsigned 32-bit integer valued arguments, set the nonnegative and ints arguments to true.

var hypot = ampbm.factory( 1.0, 0.5, true, true );

var h = hypot( 5.0, 12.0 );
// returns 14

Notes

  • The algorithm computes only an approximation. For precise results, use hypot.

Examples

var randu = require( '@stdlib/random/base/randu' );
var round = require( '@stdlib/math/base/special/round' );
var ampbm = require( '@stdlib/fastmath/special/alpha-max-plus-beta-min' );

var x;
var y;
var h;
var i;

for ( i = 0; i < 100; i++ ) {
    x = round( randu()*100.0 ) - 50.0;
    y = round( randu()*100.0 ) - 50.0;
    h = ampbm( x, y );
    console.log( 'hypot(%d,%d) = %d', x, y, h );
}

References

  • Lyons, Richard G. 2011. Understanding Digital Signal Processing, 3rd Edition. Prentice Hall.