float32-from-binary-string

From Binary String

Create a single-precision floating-point number from an IEEE 754 literal bit representation.

Usage

var fromBinaryStringf = require( '@stdlib/math/base/utils/float32-from-binary-string' );

fromBinaryStringf( bstr )

Creates a single-precision floating-point number from an IEEE 754 literal bit representation.

var bstr = '01000000100000000000000000000000';
var v = fromBinaryStringf( bstr );
// returns 4.0

bstr = '01000000010010010000111111011011';
v = fromBinaryStringf( bstr );
// returns ~3.14

bstr = '11111111011011000011101000110011';
v = fromBinaryStringf( bstr );
// returns ~-3.14e+38

The function handles subnormals.

bstr = '10000000000000000000000000010110';
val = fromBinaryStringf( bstr );
// returns ~-3.08e-44

bstr = '00000000000000000000000000000001';
val = fromBinaryStringf( bstr );
// returns ~1.40e-45

The function handles special values.

bstr = '00000000000000000000000000000000';
val = fromBinaryStringf( bstr );
// returns 0.0

bstr = '10000000000000000000000000000000';
val = fromBinaryStringf( bstr );
// returns -0.0

bstr = '01111111110000000000000000000000';
val = fromBinaryStringf( bstr );
// returns NaN

bstr = '01111111100000000000000000000000';
val = fromBinaryStringf( bstr );
// returns Number.POSITIVE_INFINITY

bstr = '11111111100000000000000000000000';
val = fromBinaryStringf( bstr );
// returns Number.NEGATIVE_INFINITY

Examples

var round = require( '@stdlib/math/base/special/round' );
var pow = require( '@stdlib/math/base/special/pow' );
var toFloat32 = require( '@stdlib/math/base/utils/float64-to-float32' );
var toBinaryStringf = require( '@stdlib/math/base/utils/float32-to-binary-string' );
var fromBinaryStringf = require( '@stdlib/math/base/utils/float32-from-binary-string' );

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

// Convert random numbers to IEEE 754 literal bit representations and then convert them back...
for ( i = 0; i < 100; i++ ) {
    if ( Math.random() < 0.5 ) {
        sign = -1.0;
    } else {
        sign = 1.0;
    }
    frac = Math.random() * 10.0;
    exp = round( Math.random()*100.0 );
    if ( Math.random() < 0.5 ) {
        exp = -exp;
    }
    x = sign * frac * pow( 2.0, exp );
    x = toFloat32( x );

    b = toBinaryStringf( x );
    y = fromBinaryStringf( b );

    console.log( '%d => %s => %d', x, b, y );
    console.log( x === y );
}