Fourier transform in MATLAB

% MATLAB code to specify the variable t 
% and u as symbolic ones The syms function
% creates a variable dynamically and 
% automatically assigns to a MATLAB variable
% with the same name
syms t u

% define time domain function x(t)
x = exp(-t^2-u^2);

% fourier command to transform into 
% frequency domain function X(w)

% using 1st syntax, where independent variable
% is determined by symvar (u in this case)
% and transformation variable is w by default.
X = fourier(x);

% using 2nd syntax, where transformation 
% variable = y
X1=fourier(x,y);

% using 3rd syntax, where independent 
% variable = t & transformation variable = y 
X2=fourier(x,t,y);

% Display the output value
disp('1. Fourier Transform of exp(-t^2-u^2) using fourier(x) :')
disp(X);

disp('2. Fourier Transform of exp(-t^2-u^2) using fourier(x,y) :')
disp(X1);

disp('3. Fourier Transform of exp(-t^2-u^2) using fourier(x,t,y) :')
disp(X2);

% MATLAB code for specify the variable
% a and t as symbolic ones
syms a t

% define time domain function x(t) 
% where t=independent variable & a=constant
x = a*abs(t);

% fourier command to transform into frequency
% domain function X(w)
% using 1st syntax
X = fourier(x);

% using 2nd syntax, where transformation 
% variable = y
X1 = fourier(x,y);

% using 3rd syntax, where transformation variable
% = y & independent
% variable = t (as t is the only other variable)
X2 = fourier(x,t,y);

% Display the output value
disp('1. Fourier Transform of a*abs(t) using fourier(x):')
disp(X);

disp('2. Fourier Transform of a*abs(t) using fourier(x,y):')
disp(X1);

disp('3. Fourier Transform of a*abs(t) using fourier(x,t,y):')
disp(X2);