# How to vectorize this piece of code and why doesn't e come out to be zero though it must come out to be zero because u and b are equal?

1 回表示 (過去 30 日間)
Sadiq Akbar 2022 年 12 月 10 日
コメント済み: Bruno Luong 2022 年 12 月 11 日
u=[30 50 75 -30 -50 -75];
b=u;
Noise=5;
M = 6;%Constant1
N = 6;%Constant2
d = 0.5;%Constant3
K = length(u)/2; %Constant4
alpha=ones(1,K);%[1 1 1 1 1];
a=zeros(M,K);%aTx
f=zeros(N,K);%fRx
c=zeros(M*N, length(u)-K);% Extended Matrix
%%%%%%%%%%%%%%%%%%%%
% Swapping vector b
%%%%%%%%%%%%%%%%%%%%
[~, ix] = sort(u); % u is my desired vector
[~, ix1(ix)] = sort(b);
b = b(ix1);
%%%%%%%%%%%%%%%%%%%%
% Observed response
%%%%%%%%%%%%%%%%%%%
for i=1:K
for h=1:M
a(h,i)=exp(j*2*pi*(h-1)*d*sind(u(i))); %%%%% a
end
for p=1:N
f(p,i)=exp(j*2*pi*(p-1)*d*sind(u(K+i))); %%%%% f
end
end
for g= 1:K
c(:,g)=kron(a(:,g),f(:,g));% Extended vector
end
yo=c*alpha'; % Observed Response (Noise Free)
yo=awgn(yo,Noise);% Uncomment for Noise consideration
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Estimated response
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
ae=zeros(M,K);
fe=zeros(N,K);
ce=zeros(M*N, length(u)-K);
for i=1:K
for h=1:M
ae(h,i)=exp(j*2*pi*(h-1)*d*sind(b(i))); %%%%% ae
end
for p=1:N
fe(p,i)=exp(j*2*pi*(p-1)*d*sind(b(K+i))); %%%%% fe
end
end
for g= 1:K
ce(:,g)=kron(ae(:,g),fe(:,g));
end
ye=ce*alpha';% Estimated Response
%%%%%%%%%%%%%%%%%
% MSE
%%%%%%%%%%%%%%%%%
e=0.0;
for s=1:M*N
e=e+(abs(yo(s,1)-ye(s,1))).^2;
end
e=e/M*N;

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### 採用された回答

Bruno Luong 2022 年 12 月 10 日
Not tested but this
for i=1:K
for h=1:M
ae(h,i)=exp(j*2*pi*(h-1)*d*sind(b(i))); %%%%% ae
end
for p=1:N
fe(p,i)=exp(j*2*pi*(p-1)*d*sind(b(K+i))); %%%%% fe
end
end
can be replaced by
h=(1:M)';
p=(1:N)';
i=1:K;
br = b(:).';
ae=exp(j*2*pi*(h-1)*d.*sind(br(i)));
fe=exp(j*2*pi*(p-1)*d.*sind(br(K+i)));
And
for g= 1:K
ce(:,g)=kron(ae(:,g),fe(:,g));
end
By
ce = reshape(reshape(ae,K,1,[]).*fe,K,[]);
##### 7 件のコメント5 件の古いコメントを表示5 件の古いコメントを非表示
Sadiq Akbar 2022 年 12 月 11 日
@Bruno Luong thank you very much for your guidance and help. I did it.
Bruno Luong 2022 年 12 月 11 日
You are welcome.

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### その他の回答 (1 件)

Walter Roberson 2022 年 12 月 10 日

format long g
u=[30 50 75 -30 -50 -75];
b=u;
Noise=5;
M = 6;%Constant1
N = 6;%Constant2
d = 0.5;%Constant3
K = length(u)/2; %Constant4
alpha=ones(1,K);%[1 1 1 1 1];
a=zeros(M,K);%aTx
f=zeros(N,K);%fRx
c=zeros(M*N, length(u)-K);% Extended Matrix
%%%%%%%%%%%%%%%%%%%%
% Swapping vector b
%%%%%%%%%%%%%%%%%%%%
[~, ix] = sort(u); % u is my desired vector
[~, ix1(ix)] = sort(b);
b = b(ix1);
%%%%%%%%%%%%%%%%%%%%
% Observed response
%%%%%%%%%%%%%%%%%%%
for i=1:K
for h=1:M
a(h,i)=exp(j*2*pi*(h-1)*d*sind(u(i))); %%%%% a
end
for p=1:N
f(p,i)=exp(j*2*pi*(p-1)*d*sind(u(K+i))); %%%%% f
end
end
for g= 1:K
c(:,g)=kron(a(:,g),f(:,g));% Extended vector
end
yo=c*alpha'; % Observed Response (Noise Free)
yo=awgn(yo,Noise);% Uncomment for Noise consideration
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Estimated response
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
ae=zeros(M,K);
fe=zeros(N,K);
ce=zeros(M*N, length(u)-K);
for i=1:K
for h=1:M
ae(h,i)=exp(j*2*pi*(h-1)*d*sind(b(i))); %%%%% ae
end
for p=1:N
fe(p,i)=exp(j*2*pi*(p-1)*d*sind(b(K+i))); %%%%% fe
end
end
for g= 1:K
ce(:,g)=kron(ae(:,g),fe(:,g));
end
ye=ce*alpha';% Estimated Response
%%%%%%%%%%%%%%%%%
% MSE
%%%%%%%%%%%%%%%%%
e=0.0;
for s=1:M*N
e=e+(abs(yo(s,1)-ye(s,1))).^2;
end
e=e/(M*N);
e2 = sum( abs(yo - ye).^2 )
e2 =
11.7479934461356
yo - ye
ans =
0.334761462628025 - 0.251604299511244i 0.178519020660132 - 0.11790756943532i 0.284315581572755 - 0.408074305354306i 0.436075962283236 + 0.0206136540004817i 0.148113323815692 - 0.1129397164173i 0.148601229842305 - 0.684227855074489i -0.045229189659987 + 1.06816976506834i 0.0449597505407739 + 0.0474860403089703i -0.117067171711324 - 0.335272836828924i -0.170838058879666 - 0.485416275775231i -1.01036972409615 + 0.0987920670194429i 0.17724058327333 + 0.358430065054272i -0.296057798011593 + 0.268159218550655i 0.219874574050923 - 0.303912184656327i -0.196397184200888 + 0.579342311435272i 0.362391793015109 - 0.00637536507210101i -0.198930152531317 + 0.17081587160563i 0.00126195142908353 + 0.196629724720236i 0.451323400274059 - 0.19338404893942i 0.0163549272291462 + 0.211263099020562i 0.153134628152902 - 0.360072343716162i 0.125618160624793 - 0.447663575852295i 0.18682261208064 - 0.440681989383234i 0.56658020901609 - 0.0413352507512756i 0.216864956628124 + 0.402128673330828i -0.650894787871801 + 0.195828199364969i 0.526482743315456 + 0.161261991699198i -0.0222655470394779 - 0.303132876336713i 0.249479128033312 - 0.125089115081018i 0.23011373904232 + 0.168827365022589i 0.37643644331261 + 0.00726229738016904i -0.933652368281796 - 0.958904637492813i -0.552407757174997 - 0.128690424103339i 0.0864282827509827 + 0.565038735206412i 0.617124996371567 - 1.11650348178558i 0.390001758508875 + 0.358139661751764i
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Walter Roberson 2022 年 12 月 10 日
I thought I had canceled that post...
I do not see any reason why the values should be the same. awgn() applies randomness, but your ye has not had any randomness applied to it (certainly not exactly the same randomness). There is no reason for them to be the same.
Sadiq Akbar 2022 年 12 月 10 日
Thanks dear Walter Roberson for your kind response. Yes, you are right that awgn() has been added to yo and not to ye. So that's the reason. But what about vectorization of the code? Can you replace all the for loops by vectorization?
Regards,

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