time-to-botec/js/node_modules/@stdlib/number/float64/base/from-binary-string/README.md

From Binary String

Create a double-precision floating-point number from a literal bit representation.

Usage

var fromBinaryString = require( '@stdlib/number/float64/base/from-binary-string' );

fromBinaryString( bstr )

Creates a double-precision floating-point number from a literal bit representation.

var bstr = '0100000000010000000000000000000000000000000000000000000000000000';
var val = fromBinaryString( bstr );
// returns 4.0

bstr = '0100000000001001001000011111101101010100010001000010110100011000';
val = fromBinaryString( bstr );
// returns 3.141592653589793

bstr = '1111111111100001110011001111001110000101111010111100100010100000';
val = fromBinaryString( bstr );
// returns -1.0e308

The function handles subnormals.

var bstr = '1000000000000000000000000000000000000000000000000001100011010011';
var val = fromBinaryString( bstr );
// returns -3.14e-320

bstr = '0000000000000000000000000000000000000000000000000000000000000001';
val = fromBinaryString( bstr );
// returns 5.0e-324

The function handles special values.

var bstr = '0000000000000000000000000000000000000000000000000000000000000000';
var val = fromBinaryString( bstr );
// returns 0.0

bstr = '1000000000000000000000000000000000000000000000000000000000000000';
val = fromBinaryString( bstr );
// returns -0.0

bstr = '0111111111111000000000000000000000000000000000000000000000000000';
val = fromBinaryString( bstr );
// returns NaN

bstr = '0111111111110000000000000000000000000000000000000000000000000000';
val = fromBinaryString( bstr );
// returns Infinity

bstr = '1111111111110000000000000000000000000000000000000000000000000000';
val = fromBinaryString( bstr );
// returns -Infinity

Examples

var randu = require( '@stdlib/random/base/randu' );
var round = require( '@stdlib/math/base/special/round' );
var pow = require( '@stdlib/math/base/special/pow' );
var toBinaryString = require( '@stdlib/number/float64/base/to-binary-string' );
var fromBinaryString = require( '@stdlib/number/float64/base/from-binary-string' );

var frac;
var sign;
var exp;
var b;
var x;
var y;
var i;

// Convert random numbers to literal bit representations and then convert them back...
for ( i = 0; i < 100; i++ ) {
    if ( randu() < 0.5 ) {
        sign = -1.0;
    } else {
        sign = 1.0;
    }
    frac = randu() * 10.0;
    exp = round( randu()*100.0 );
    if ( randu() < 0.5 ) {
        exp = -exp;
    }
    x = sign * frac * pow( 2.0, exp );
    b = toBinaryString( x );
    y = fromBinaryString( b );
    console.log( '%d => %s => %d', x, b, y );
    console.log( x === y );
}