# How can I check whether the strictly positive elements of each row of a matrix are equal?

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MRC on 29 Apr 2014
Commented: dpb on 29 Apr 2014
How can I check whether the strictly positive elements of each row of a matrix are equal? E.g. if
A=[0 1 1 2; 0 1 0 1; 3 0 3 0]
I want
B=[0;1;1]
Geoff Hayes on 29 Apr 2014

per isakson on 29 Apr 2014
Edited: per isakson on 29 Apr 2014
arrayfun( @(jj) (length(unique(A(jj,(A(jj,:)>0)))) == 1),(1:size(A,1)) )
returns
ans =
0 1 1

Sara on 29 Apr 2014
B = zeros(size(A,1),1);
for i = 1:size(A,1)
temp = A(i,:);
temp = temp(temp>0);
temp = unique(temp);
if(length(temp) == 1)
B(i) = 1;
end
end

dpb on 29 Apr 2014
isPos=false(size(A,1),1);
for i=1:size(A,1)
isPos(i)=all(diff(A(i,A(i,:)>0))==0);
end
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dpb on 29 Apr 2014
Yes, w/ arrayfun. That was left as "exercise for the student" :)
As illustrated by Per; same idea with anonymous function. As also showed, any of a number of ways to check on the consistency of the values in a row is doable.