## unwrap phase

A Boolean specifying whether to unwrap the phase.

True |
Unwraps the phase. |

False |
Does not unwrap the phase. |

Unwrapping eliminates discontinuities that have an absolute value greater than pi.

**Default: **False

## signal

The input time-domain signal, usually in volts.

This input can be a 1D array of double-precision floating-point numbers or a 1D array of complex double-precision floating-point numbers.

The time-domain record must contain at least three cycles of the signal for a valid estimate.

## error in

Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.

**Default: **No error

## dt

The sample period of the time-domain signal, usually in seconds.

Set this input to 1/*fs*, where *fs* is the sampling frequency of the time-domain signal.

**Default: **1

## magnitude

The magnitude of the single-sided power spectrum.

## phase

The single-sided amplitude spectrum phase, in radians.

## df

The frequency interval of the power spectrum. The unit of this output is Hz if the sample period is in seconds.

## Algorithm for Calculating the Amplitude Spectrum

To compute the single-sided, scaled amplitude spectrum, this node first uses the following equation to compute the two-sided amplitude spectrum:

$\begin{array}{cc}A\left(i\right)=\frac{X\left(i\right)}{N}& i=0,\text{\hspace{0.17em}}1,\text{\hspace{0.17em}}\mathrm{...},\text{\hspace{0.17em}}N-1\end{array}$

where

*A* is the two-sided amplitude spectrum
*X* is the discrete Fourier transform of **signal**
*N* is the number of points in **signal**

Then, this node uses the following equation to convert the two-sided amplitude spectrum to the single-sided amplitude spectrum:

$B\left(i\right)=\{\begin{array}{cc}A\left(0\right)& i=0\\ \sqrt{2}A\left(i\right)& i=1,\text{\hspace{0.17em}}2,\text{\hspace{0.17em}}\mathrm{...},\text{\hspace{0.17em}}\lfloor \frac{N}{2}-1\rfloor \end{array}$

where *B* is the single-sided amplitude spectrum and
$\lfloor \rfloor $ is the floor operation.

This node computes the magnitude of the single-sided amplitude spectrum *B* as **magnitude** = *B* and the phase as *phase*(*B*).

**Where This Node Can Run: **

Desktop OS: Windows

FPGA: Not supported