optimized

hod2/DFT_priama.m

@@ -1,13 +1,13 @@
 % priama X(k) z x(n)
 function X = DFT_priama(x)
-  X = [];
   N = length(x);
+  X = zeros(1,N);
   for k = 0:(N - 1)
     Xk = 0;
     for n = 0:(N - 1)
       Xk = Xk + ( x(n + 1) .* exp(-1j * 2 * pi * n * k / N) );
     end
-    X(end + 1) =  Xk;
+    X(k + 1) =  Xk;
   end
   X = 1/N * X;
 end

hod2/DFT_spatna.m

@@ -1,13 +1,13 @@
 % spatna x(n) z X(k)
 function x = DFT_spatna(X)
-  x = [];
   N = length(X);
+  x = zeros(1,N);
   for n = 0:(N - 1)
     xn = 0;
     for k = 0:(N - 1)
       xn = xn + ( X(k + 1) .* exp(1j * 2 * pi * n * k / N) );
     end
-    x(end + 1) =  xn;
+    x(n + 1) =  xn;
   end
 end