double-bits
Routines for manipulating binary representations of a IEEE 754 double precision numbers.
Example
var db = require("double-bits")
console.log(db.hi(1.0).toString(16))
console.log(db.lo(1.0).toString(16))
console.log(db.pack(0, 0x3ff00000))
var pad = require("pad")
function base2Str(n) {
var f = db.fraction(n)
return (db.sign(n) ? "-" : "") +
"2^" + (db.exponent(n)+1) +
" * 0." + pad(f[1].toString(2), 20, "0") +
pad(f[0].toString(2), 32, "0")
}
console.log(base2Str(1.0))
Install
npm install double-bits
API
var db = require("double-bits")
db(n)
Returns a pair of 32-bit unsigned ints encoding the lower/higher order words respectively representing n
n
is an IEEE754 double number
Returns An array, [lo,hi]
encoding n
db.lo(n)
Returns the lower order word of n
Returns The lower order word of n
db.hi(n)
Returns the higher order word of n
Returns The higher order word of n
db.pack(lo, hi)
Given a pair of lower/higher order words, concatenate them into a 64 bit double precision number
lo
is the lower order wordhi
is the higher order word
Returns An IEEE754 double precision number formed by concatenating the bits of lo
and hi
db.sign(n)
Returns the state of the sign bit of n
n
is an IEEE754 double precision number
Returns The sign bit of n
db.exponent(n)
Returns the exponent of n
n
is an IEEE754 double precision number
Returns The exponent of n
db.fraction(n)
Returns the fractional part of n
n
is an IEEE754 double precision number
Returns The fractional part of n
encoded as a pair of numbers, [lo,hi]
where lo
is a 32 bit integer and hi
is a 21 bit integer.
db.denormalized(n)
Test if a double is denormalized.
Returns true
if n
is denormal, false
otherwise
Credits
(c) 2014 Mikola Lysenko. BSD License