Signal Processing Toolbox

abs

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