abs (Signal Processing Toolbox)

Absolute value (magnitude)

abs is a MATLAB function.

Signal-Specific Example

Calculate the magnitude of the FFT of a sequence.

t = (0:99)/100;                   % Time vector
x = sin(2*pi*15*t) + sin(2*pi*40*t); % Signal
y = fft(x);                       % Compute DFT of x
m = abs(y);                       % Magnitude

Plot the magnitude:

f = (0:length(y)-1)'/length(y)*100; % Frequency vector
plot(f,m)

Functions -- Alphabetical List ac2poly