@stdlib/number-float64-base-from-binary-string
v0.2.2
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Create a double-precision floating-point number from a literal bit representation.
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From Binary String
Create a double-precision floating-point number from a literal bit representation.
Installation
npm install @stdlib/number-float64-base-from-binary-string
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 );
}
See Also
@stdlib/number-float32/base/from-binary-string
: create a single-precision floating-point number from a literal bit representation.@stdlib/number-float64/base/to-binary-string
: return a string giving the literal bit representation of a double-precision floating-point number.
Notice
This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.
Community
License
See LICENSE.
Copyright
Copyright © 2016-2024. The Stdlib Authors.