Computes the base 2 logarithm of a specified input value.

If **x** is 0, **log2** is negative infinity. If **x** is not complex and is less than 0, **log2** is not a number (NaN).

## x

An input to this operation.

This input supports scalar numbers, arrays or clusters of numbers, and arrays of clusters of numbers.

Data Type Changes on FPGA

When you add this node to a document targeted to an FPGA, this input has a default data type that uses fewer hardware resources at compile time.

## log2

Result of the operation.

This output assumes the same numeric representation as

**x**. When

**x** is of the form

**x** = a + bi, that is, when

**x** is complex, the following equation defines

**log2**:

$\mathrm{log}2(x)=\frac{\mathrm{ln}(x)}{\mathrm{ln}(2)}=\frac{1}{\mathrm{ln}(2)}(\mathrm{ln}\left(\sqrt{{a}^{2}+{b}^{2}}\right)+i\mathrm{arctan}2(b,a))$

**Where This Node Can Run: **

Desktop OS: Windows

FPGA: All devices (only within an optimized FPGA VI)

Web Server: Not supported in VIs that run in a web application