1 files changed, 31 insertions, 0 deletions
diff --git a/2279/CH7/EX7.8/Ex7_8.sce b/2279/CH7/EX7.8/Ex7_8.sce
new file mode 100644
index 000000000..5257de458
--- /dev/null
+++ b/2279/CH7/EX7.8/Ex7_8.sce
@@ -0,0 +1,31 @@
+//x[n] = 1+sin(2*%pi/N)n+3cos(2*%pi/N)n+cos[(4*%pi/N)n+%pi/4]
+clear;
+close;
+clc;
+N = 10;
+n = 0:0.01:N;
+Wo = 2*%pi/N;
+xn =ones(1,length(n))+sin(Wo*n)+3*cos(Wo*n)+cos(2*Wo*n+%pi/4);
+for k =0:N-2
+  C(k+1,:) = exp(-sqrt(-1)*Wo*n.*k);
+  a(k+1) = xn*C(k+1,:)'/length(n);
+  if(abs(a(k+1))<=0.1) 
+    a(k+1)=0;
+  end
+end
+a =a';
+a_conj =conj(a);
+ak = [a_conj($:-1:1),a(2:$)];
+Mag_ak = abs(ak);
+for i = 1:length(a)
+  Phase_ak(i) = atan(imag(ak(i))/(real(ak(i))+0.0001));
+end
+Phase_ak = Phase_ak'
+Phase_ak = [Phase_ak(1:$-1) -Phase_ak($:-1:1)];
+k = -(N-2):(N-2);
+subplot(2,1,1)
+plot2d3('gnn',k,Mag_ak,5)
+xtitle('abs(ak)','k','ak')
+subplot(2,1,2)
+plot2d3('gnn',k,Phase_ak,5) 
+xtitle('phase(ak)','k','ak')