phase plot no giving the correct plot
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%clc;
%clear all;
%close all;
N=6;
n=0:N-1;
x=sin(2*pi*n/6);
for k=0:N-1
sum=0;
for n=0:N-1
A=exp(-j*k*((2*pi)/N)*n);
B=A*x(n+1);
sum=sum+B;
end
a(k+1)=sum/N;
end
a
mag=abs(a);
phase=angle(a);
k=0:N-1
subplot(2,1,1);
stem(k,mag);
title('magnitude plot 73020')
grid on;
subplot(2,1,2);
stem(k,phase);
title('phase plot 73020')
grid on;
the figure shows the output but the phase plot is not correct.
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Answers (1)
dpb
on 19 Jul 2019
Don't forget floating point precision...
>> real(a)
ans =
1.0e-15 *
0.0555 0.1665 0.0555 0.0185 -0.1295 -0.9899
>> imag(a)
ans =
0 -0.5000 0.0000 0.0000 0.0000 0.5000
>> real(a)<3*eps
ans =
1×6 logical array
1 1 1 1 1 1
>>
Perhaps what you were expecting was on the order of...
>> angle(complex(zeros(size(a)),imag(a)))
ans =
0 -1.5708 1.5708 1.5708 1.5708 1.5708
>>
But, the plot is correct given the input; as is the result of angle -- just not the same as the analytic solution.
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