hodina 2

hod2/1.m

@@ -0,0 +1,27 @@
+% X(k)=1/N \sum_{n=0}^{N-1} x(n)*e^{-j*2*\pi*n*k/N}
+% x(n)=\sum_{n=0}^{N-1} X(k)e^{j*2*\pi*n*k/N}
+
+x = [8,8,8,8,8,8,8,8]
+X = []
+N = length(x)
+
+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;
+end
+X = 1/N * X
+
+temp = 1/N * fft(x)
+
+y = [];
+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
+  y(end + 1) =  xn;
+end
+y

hod2/2.m

@@ -0,0 +1,9 @@
+% X(k)=1/N \sum_{n=0}^{N-1} x(n)*e^{-j*2*\pi*n*k/N}
+% x(n)=\sum_{n=0}^{N-1} X(k)e^{j*2*\pi*n*k/N}
+
+
+x = [8,8,8,8,8,8,8,8]
+X = DFT_priama(x)
+
+x = DFT_spatna(X)
+

hod2/DFT_priama.m

@@ -0,0 +1,13 @@
+% priama X(k) z x(n)
+function X = DFT_priama(x)
+  X = [];
+  N = length(x);
+  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;
+  end
+  X = 1/N * X;
+end

hod2/DFT_spatna.m

@@ -0,0 +1,13 @@
+% spatna x(n) z X(k)
+function x = DFT_spatna(X)
+  x = [];
+  N = length(X);
+  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;
+  end
+end
+