FFTGUI Demonstration of Finite Fourier Transform.
FFTGUI(y) plots real(y), imag(y), real(fft(y)) and imag(fft(y)).
FFTGUI, without any arguments, uses y = zeros(1,32).
When any point is moved with the mouse, the other plots respond.
Inspired by Java applet by Dave Hale, Stanford Exploration Project,
http://sepwww.stanford.edu/oldsep/hale/FftLab.html
/*
* EULER S ALGORITHM 5.1
*
* TO APPROXIMATE THE SOLUTION OF THE INITIAL VALUE PROBLEM:
* Y = F(T,Y), A<=T<=B, Y(A) = ALPHA,
* AT N+1 EQUALLY SPACED POINTS IN THE INTERVAL [A,B].
*
* INPUT: ENDPOINTS A,B INITIAL CONDITION ALPHA INTEGER N.
*
* OUTPUT: APPROXIMATION W TO Y AT THE (N+1) VALUES OF T.
*/
