## Amplitude spectrum

Purpose
Description
Example
Macro Synopsis
Modules
Related Functions

### Purpose

Amplitude spectrum of a signal in the frequency domain

### Description

Amplitude spectrum calculates the amplitude spectrum, i.e. the amplitude distribution as a function of the frequency, of the given signal according to

by performing a Fast Fourier Transform (FFT) within a window slided along the signal.

Parameters of this function are

• window length N in samples
• window overlap M in samples.

Note: The type of window function and type of FFT algorithm can be adjusted in dialog appearing by selecting Basic Options from the Basics menu.

Warning: Note that y(0) is suppressed in order to avoid its large values dominating the result.

### Example

If you calculate the amplitude spectrum of a pure sine, the total integral of the result (use Signal info to calculate the integral) is equal to the amplitude of the sine (provided you have set 'Boxcar' windowing in Basic Options).

### Macro Synopsis

y = AmplSpect(x,N,M);
signal x,y;
int N,M;

Spectral

### Related Functions

Phase spectrum, Power spectrum, Fourier transform.