# GroupDelay Function

Returns the group delay of the argument. Group delay is defined as:

$\frac{d}{dx}\left(\text{phase}\left(y\right)\right)\cdot \frac{1}{2\pi}$

where $y$ is the supplied vector and $x$ is its reference. The GroupDelay function expects the result of an AC analysis where $y$ is a voltage or current and its reference is frequency.

This function will yield an error if its argument is complex and has no reference.

### Arguments

 Number Type Compulsory Default Description 1 real/complex array Yes Vector

### Returns

Return type: real array