Check if any elements of cell array are equal ?
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Suppose if I have cell array a{1}=[1 1 0]; a{2}=[0 0 0]; a{3}=[0 0 0]. I want to check if any elements of the cell array are equal. If i use " isequal(a{:}) " then it returns "Logical 0". However, we can see that a{2} == a{3}. So, i need the answer to be "Logical 1" as some of the elements of the cell array are equal. Is there any built-in function to check that directly in MATLAB.
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KALYAN ACHARJYA
2019년 6월 13일
편집: KALYAN ACHARJYA
2019년 6월 13일
Yes, but it can be done using multiple steps, not in single function.
채택된 답변
Stephen23
2019년 6월 14일
편집: Stephen23
2019년 6월 14일
Matching:
>> a{1}=[1,1,0];
>> a{2}=[9,9,9,9];
>> a{3}=[1,1,0];
>> a{4}=[];
>> N = numel(a);
>> [X,Y] = ndgrid(1:N);
>> Z = tril(true(N),-1);
>> any(arrayfun(@(x,y)isequal(a{x},a{y}),X(Z),Y(Z)))
ans = 1
vs. non-matching:
>> a{1}=[1,1,1];
>> any(arrayfun(@(x,y)isequal(a{x},a{y}),X(Z),Y(Z)))
ans = 0
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추가 답변 (2개)
madhan ravi
2019년 6월 13일
편집: madhan ravi
2019년 6월 14일
This method works for cells with contents of any sizes:
a{1}=[1 1 0]; % example array
a{2}=[0 10];
a{3}=[1 1 0];
Result = false;
for k = 1:numel(a)
for l = 1:numel(a)
if k~=l
if isequal(a{k},a{l})
Result = true;
break
end
end
end
end
Note: The below two methods assume each cell has the same number of elements.
a{1}=[1 1 0];
a{2}=[0 0 0];
a{3}=[0 0 0];
A = vertcat(a{:});
Result = false;
for k = 1:numel(a)
if nnz(ismember(A,a{k},'rows'))>1
Result = true;
break
end
end
% or
idx=all(A'==permute(reshape(A,[],1,size(A,1)),[3,2,1]));
Result=any(squeeze(sum(idx,2))>1)
Choose which method you like the best , some mould can be given to the above but I’m off for the day perhaps will look into it tomorrow.
댓글 수: 3
Stephen23
2019년 6월 14일
편집: Stephen23
2019년 6월 14일
+1 the nested loops (first algorithm) is probably the most efficient approach to this. Note that break only exits the inner loop while the outer loop keeps running (but this does not affect the result). An improvement to avoid testing pairs of arrays twice is to use the outer-loop's iteration variable to set the range of the inner loop (here the short-circuit || makes the code quite efficient without break), e.g.:
>> a{1}=[1,1,0];
>> a{2}=[9,9,9,9];
>> a{3}=[1,1,0];
>> a{4}=[];
>> N=numel(a);
>> Z=false;
>> for x=1:N, for y=x+1:N, Z=Z||isequal(a{x},a{y}); end, end
>> Z
Z = 1
VK Bhardwaj
2019년 6월 13일
편집: VK Bhardwaj
2019년 6월 14일
function y = checkequal(x)
% Input 'x' should be cell array
% Output 'y' logical value true. If any input cell array index is equal to
% another else false
% Example1:
% a{1}=[1 1 0]; a{2}=[0 0 0]; a{3}=[0 0 0];
% y = checkequal(a);
% Output is y = logical(1)
% Example2:
% a{1}=[1 1 0]; a{2}=[0 1 0]; a{3}=[0 0 0];
% y = checkequal(a);
% Output is y = logical(0)
y = false;
num = numel(x);
for i = 1:num
for j = 1:num
if i~=j
if isequal(x{i},x{j})
y = true;
return;
end
end
end
end
end
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