Why this code gives error on line 47?

Question

Sadiq Akbar 2022-12-29

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1885937-why-this-code-gives-error-on-line-47

评论： Image Analyst 2022-12-30

epuma.zip

I downloaded the code attached from the following URL of Mathworks site:

URL: https://www.mathworks.com/matlabcentral/fileexchange/67710-enhanced-puma-for-doa-estimation?s_tid=answers_rc2-3_p6_MLT

When I run it, it gives the folloing error which I don't know why?

Unrecognized function or variable 'vec'.

Error in EPUMA>pumaUpdate (line 47)

f = -vec(U(L+1:end,:));

Error in EPUMA (line 26)

DOA_Cand = pumaUpdate(U, S, L, K, maxIter);

Error in demo (line 25)

doa_estimates = EPUMA(x, K);

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Torsten 2022-12-30

在 MATLAB Online 中打开

M   = 10;           % # of sensors
N   = 40;           % # of samples
doa = [1,18];       % direction-of-arrivals
K   = length(doa);  % number of sources
SNR = 10;           % signal-to-noise ratio
% array manifold, ULA with half-interelement spacing
A  = exp(1j*[0:M-1]'*pi*sind(doa));
% uncorrelated source signals
% st = (randn(K,N) + 1j*randn(K,N))/sqrt(2);
% coherent source signals
st = (randn(K,N) + 1j*randn(K,N))/sqrt(2);
st(1,:) = st(2,:);
% additive noise
nt = (randn(M,N) + 1j*randn(M,N))/sqrt(2);
% received signal
x  = A*st*10^(SNR/20) + nt;
doa_estimates = EPUMA(x, K);
norm(doa_estimates(:) - doa(:))^2
ans = 0.0048
function [doa_hat] = EPUMA(x, K, L, maxIter)
%% If you find the code is useful, please cite our paper
% C. Qian, L. Huang, N. D. Sidiropoulos and H. C. So,
% "Enhanced PUMA for direction-of-arrival estimation and its performance analysis,"
% IEEE Transactions on Signal Processing, vol.64, no.16, pp.4127-4137, 2016.
%%
warning off;
if nargin<3
    L = K + 1;
    maxIter = 3;
elseif nargin<4
    maxIter = 3;
end
[M,N] = size(x);
R     =  x*x'/N;
J     =  fliplr(eye(M));
R     =  0.5*(R + J*conj(R)*J);
[U,S] =  svd(R);
U     =  U(:,1:K);
S     =  diag(S);
DOA_Cand = pumaUpdate(U, S, L, K, maxIter);
%DOA_bank = combntns(DOA_Cand,K);
DOA_bank = nchoosek(DOA_Cand,K);
for i = 1:size(DOA_bank,1)
    A = exp(1j*pi*[0:M-1]'*sind(DOA_bank(i,:)))/sqrt(M);
    mlObjVal(i) = trace((eye(M)-A/(A'*A)*A')*R);
end
[~,I] = min(mlObjVal);
doa_hat = sort(DOA_bank(I,:));
end
function DOA = pumaUpdate(U,S,L,K,maxitr)
M = size(U,1);
D = [];
for i = 1:K
    D = [D; toeplitz(U(L:M-1,i), U(L:-1:1,i))];
end
f = -vec(U(L+1:end,:));
sigman2 = mean(S(K+1:M));
SS = S(1:K) + 1e-10;
c = D\f;
for i = 1:maxitr
    A = toeplitz([c(L),zeros(1,M-L-1)].', [fliplr(c.'),1,zeros(1,M-L-1)]);
    W = kron(diag((SS - sigman2).^2./SS), inv(A*A'));
    c = (D'*W*D)\D'*W*f;
end
c1 = c;
c = [1, c1.'];
rs = roots(c);
DOA = asin(angle(rs)/pi)*180/pi;
end
function v = vec(m)
%Helper function to turn a matrix of any size into a column vector using (:)
%    This function is meant to make one-line computations easy/fast when
%    subscripting already.
%SCd 01/04/2011 (First function of 2011!)
%
%Updates: -05/24/2011: Used reshape instead of colon for speed.
%
%Usage: v = vec(m)
%
%Example:
%    %Original way to one line the median of a slice of 3d matrix:
%    M = repmat(magic(200),[1 1 200]); %200x200x200 magic squares
%    Mmed = median(reshape(M(:,:,34),[],1)); %34th slice
%
%    %Using the vec() function
%    Mmed = median(vec(M(:,:,34)));
%
%Input Arguments:
%   -m: matrix of any size
%
%Output Arguments:
%   -v: m(:)
%
%See Also: colon reshape
%
v = reshape(m,numel(m),1);
end

Torsten 2022-12-30

@Star Strider

https://de.mathworks.com/matlabcentral/answers/370525-how-can-i-make-a-vector-in-matlab-like-vec-x

Seems that by chance it's the "correct" vec-function.

Star Strider 2022-12-30

Thanks.

I discovered that in my search, however I wasn’t certain it was the correct function. since I had no idea what the result was supposed to be.

In any event, a version of it should have been included in the ‘EPUMA’ function files.

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Answer 1

Image Analyst 2022-12-30

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1885937-why-this-code-gives-error-on-line-47#answer_1138297

在 MATLAB Online 中打开

Try this:

f = -U(L + 1 : end, :); % Extract rows (L+1) downwards, and all columns.  f will be a 2-D matrix.
% Turn this 2-D matrix f into a column vector.  
% Stack columns underneath each other, like [col1; col2; col3; col4; last column]
f = f(:); 

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Sadiq Akbar 2022-12-30

@Image Analyst I always accept the answer when I get satisfied. Actually I didn't know about the vote till date. However now it is known to me but the option is not available, therefore cannot do it though I would like to do it. However, thanks to all of you oncd again.

Image Analyst 2022-12-30

The vote capability is for other users to say that an answer is good. Sometimes original posters just accept the first one blindly. Sometimes just because it's the first one on the list and they think they can accept multiple answers (if there were multiple ones that were right). Or sometimes they accepted too quickly (like as soon as they got the very first answer) and another one comes along shortly afterwards. They can Unaccept and accept the better one, but few people bother to do that. So the votes are for the community to say which one they think is really the best answer. Or sometimes, not the absolute best answer but just a very good answer that they think the Answerer should get credit for in terms of Reputation Points. Mathworks can extend certain perks to high earning Answerers (privileges, swag mechandise, etc.) so that's why people like to earn points.

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Why this code gives error on line 47?

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Why this code gives error on line 47?

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