# Natural Logarithm (G Dataflow)

Computes the base e natural logarithm of a specified input value.

If x is 0, ln is - $\infty$. If x is not complex and is less than 0, ln is not a number (NaN).

For very small values of x, Natural Logarithm (Arg +1) is more accurate than adding 1 to x then using this node.

## x

An input to this operation.

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

## ln

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 the natural logarithm ln:
$\mathrm{ln}\left(x\right)=\mathrm{ln}\left(|x|\right)+i\mathrm{arg}\left(x\right)$
where arg( x) is the phase of x over the interval $-\pi <\mathrm{arg}\left(x\right)\le \pi$. In other words, the output uses the following equation:
$\mathrm{ln}\left(x\right)=\mathrm{ln}\left(\sqrt{{a}^{2}+{b}^{2}}\right)+i\mathrm{arctan}2\left(b,a\right)$

Where This Node Can Run:

Desktop OS: Windows

FPGA: DAQExpress does not support FPGA devices