DTFT in matlab

dtft.m

function [ X ] = dtft( x, n, w )
% [X] = dtft(x, n, w)
% X = DTFT values computed at w frequencies
% x = finite duration sequence over n
% n = sample position vector
% w = frequency location vector

temp = w' * n;
temp = -1i * temp;

e = exp(temp);

X = e * x';

end

dtft_test.m

w = -2*pi:0.01:2*pi;
n = 0:1:100;
w0 = 2;
x = exp(n .* (1i*w0)); % x = exp(jw0n)

X = dtft(x, n, w);

subplot(2,1,1); plot(n, x); title('signal = exp(jw0n)');
subplot(2,1,2); plot(w, X); title('DTFT');

gistfile1.txt

What I wanted to achieve in the implementation of DTFT was not using `for` loops.

Looking at the example it must be clear how to use this function.

i need program dtft without using built in function!!

too many error in the program

% Enter the range of non zero values of x
n=input('Enter array n (starting to ending value for the axis of x: ');
N=length(n);
%Finding x
x=[ ]
fori=n(1):n(length(n))
if(i<0)
a=0;
else
a=(1/2).^i;
end
x=[x a];
end

subplot(2,1,1)
stem(n,x)
title('Original')
X=DTFT(x,N)
subplot(2,1,2)
ezplot(abs(X))
title('Transform')

%DTFT Function
function[X]=DTFT(x,N)
symsw;
n=0:N-1;
f=x.exp(-1jw*n);
X=sum(f);
end

help me to solve this problem...