fourier transform problem

Hi, i am trying make my own matlab program for fourier transform, whose result should be same as inbuilt library function fourier(f).

my program is:

function [fw]=myfourier(fx) syms x w; w=1; fw=int(fx*exp(-i*w*x),x,-pi,pi); and answer came are:

-pi*i for the myfourier(sin(x))

but by the library function:fourier(sin(x)) i got:

-pi*i(dirac(w - 1) - dirac(w + 1))*

and other answers are also different for different functions.

please help me for this program.

thanxs

[Alok Verma]

Hi walter,

I have sending my function again:

function [fw]=myfourier(fx)

syms x w;

w=1;

fw=int(fx*exp(-i*w*x),x,-pi,pi);

in this function i got the answer '-pi*i'

but the answer of inbuit function is:

-pi*i(dirac(w - 1) - dirac(w + 1))

if possible help me.

i m not able to get the correct answer as given by library function. may be the problem of 'w'(omega) or aomthing problem of discontinuity of function.

i hope u now understand the problem.

[Leyla Ibrahimli]

I also experience the same problem. The inverse fourier works with formula, because you dont have diracs there. I also tried (rewrite, f, dirac) but dirac is not a valid command in rewrite. So, if anyone solved the issue, it would be very nice to see the code thanks!

Answer 1

[Walter Roberson]

function [F(v)]=myfourier3(f(u))

is not legal syntax in MATLAB.

Please post your actual code.

[Alok Verma]

Hi walter,

I have sending my function again:

function [fw]=myfourier(fx)

syms x w;

w=1;

fw=int(fx*exp(-i*w*x),x,-pi,pi);

in this function i got the answer '-pi*i'

but the answer of inbuit function is:

-pi*i(dirac(w - 1) - dirac(w + 1))

if possible help me.

i m not able to get the correct answer as given by library function. may be the problem of 'w'(omega) or aomthing problem of discontinuity of function.

i hope u now understand the problem.

[Walter Roberson]

fourier involves integration from -infinity to +infinity, not -pi to +pi