Difference between revisions of "Math.frexp"

From GiderosMobile
Line 21: Line 21:
 
<source lang="lua">
 
<source lang="lua">
 
local m, n = math.frexp(16.4)
 
local m, n = math.frexp(16.4)
print("mantissa", m, "exponent", n)
+
print("mantissa", m, "exponent", n) -- mantissa 0.5125 exponent 5
print(m*2^n)
+
print(m*2^n) -- 16.4
 
</source>
 
</source>
  

Revision as of 10:31, 14 November 2022

Available since: Gideros 2011.6
Class: math

Description

Used to split a floating-point number (v) into a normalized fraction (a mantissa) and an integer exponent.

(number) (number) = math.frexp(v)

Returns m and e such that v = m*2^e, e is an integer and the absolute value of m is in the range [0.5, 1) (or zero when v is zero). The mantissa has the same sign as the argument v.

Parameters

v: (number) value

Return values

Returns (number) the mantissa, a multiplier in the range [0.5, 1) (normalized fraction)
Returns (number) the exponent as an integer

Example

local m, n = math.frexp(16.4)
print("mantissa", m, "exponent", n) -- mantissa 0.5125 exponent 5
print(m*2^n) -- 16.4

Note

math.ldexp is the inverse operation.