rempio2
Compute
x - nπ/2 = r
.
Usage
var rempio2 = require( '@stdlib/math/base/special/rempio2' );
rempio2( x, y )
Computes x - nπ/2 = r
. The function returns n
and stores the remainder r
as two numbers in y
, such that y[0]+y[1] = r
.
var y = [ 0.0, 0.0 ];
var n = rempio2( 128.0, y );
// returns 81
var y1 = y[ 0 ];
// returns ~0.765
var y2 = y[ 1 ];
// returns ~3.618e-17
When x
is NaN
or infinite, the function returns zero and sets the elements of y
to NaN
.
var y = [ 0.0, 0.0 ];
var n = rempio2( NaN, y );
// returns 0
var y1 = y[ 0 ];
// returns NaN
var y2 = y[ 1 ];
// returns NaN
y = [ 0.0, 0.0 ];
n = rempio2( Infinity, y );
// returns 0
y1 = y[ 0 ];
// returns NaN
y2 = y[ 1 ];
// returns NaN
Notes
- For input values larger than
2^20*π/2
in magnitude, the function only returns the last three binary digits ofn
and not the full result.
Examples
var linspace = require( '@stdlib/array/base/linspace' );
var rempio2 = require( '@stdlib/math/base/special/rempio2' );
var x = linspace( 0.0, 100.0, 100 );
var y = [ 0.0, 0.0 ];
var n;
var i;
for ( i = 0; i < x.length; i++ ) {
n = rempio2( x[ i ], y );
console.log( '%d - %dπ/2 = %d + %d', x[ i ], n, y[ 0 ], y[ 1 ] );
}