# log2

dissect floating-point numbers into base 2 exponent and mantissa.

## Syntax

* R = log2(M)
* \[F, E] = log2(M)

## Input argument

* M - a variable: a matrix

## Output argument

* R - result of log2: computes the base 2 logarithm of the elements of X.
* F - Mantissa values that satisfy this equation: M= F.\*2.^E
* E - Exponent values that satisfy this equation: M= F.\*2.^E

## Description

**log2** dissects several numbers into the exponent and mantissa.

\[F, E] = log2(M), any zeros in M produce F = 0 and E = 0.

Input values of Inf, -Inf, or NaN are returned unchanged in F with a corresponding exponent of E = 0.

Used function(s)

std::frexp and std::logb C++ functions

## Example

```matlab
x = [1+i,-i;i,2i];
R = log2(x)
[F, E] = log2(x)
```

## See also

[log](log), [log10](log10).

## History

| Version | Description     |
| ------- | --------------- |
| 1.0.0   | initial version |

## Author

Allan CORNET
