how can I get the max of the values between NaN's in an array
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I have an array like this one:
T = [NaN NaN; ...
1 3;
2 4;
5 6;
8 7;
NaN NaN;
NaN NaN;
4 5;
6 7;
NaN NaN;
NaN NaN;
1 2;
2 4;
5 6;
NaN NaN];
Now I'd like to add the columns of the values between the Nan's and get the max values of the sums. So the outcome in this case would be:
max = [15; 13; 11]
I tried this:
NaNloc=isnan(T);
ind=find(NaNloc(:,1));
for i=1:(length(ind)-1)
if ind(i+1)-ind(i) >1
patloc=[ind(i) ind((i+1))];
patarray=patloc(1):1:patloc(2);
for j=patarray(1):patarray(length(patarray))
a=T(j,:);
f=a(1)+a(2);
fsave(j-patloc(1)+1,:)=f;
end
max(fsave)
end
end
but I get the outcome: 15 15 11
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Accepted Answer
Azzi Abdelmalek
on 10 Jun 2014
Edited: Azzi Abdelmalek
on 10 Jun 2014
T = [NaN NaN; 1 3; 2 4; 5 6; 8 7; NaN NaN; NaN NaN; 4 5; 6 7; NaN NaN; NaN NaN; 1 2; 2 4; 5 6; NaN NaN;4 5];
h=[1;isnan(T(:,1)) ;1]';
out=arrayfun(@(x,y) max(sum(T(x:y,:),2)),strfind(h,[1 0]),strfind(h,[0 1])-1)
More Answers (2)
Matt J
on 10 Jun 2014
Edited: Matt J
on 10 Jun 2014
T=sum(T,2);
lims=reshape(find(isnan(T)),2,[]);
n=size(lims,2);
result=nan(1,n);
for i=1:n
result(i)=max(T(lims(1,i)+1:lims(2,i)-1));
end
3 Comments
Matt J
on 10 Jun 2014
I don't fully understand your original code, but here is how I would extract each individual block of T
if ~isnan(T(1))
T=[nan,nan;T];
end
if ~isnan(T(end))
T=[T;nan,nan];
end
nanloc=find(isnan(T(:,1)));
for i=1:length(nanloc)-1
a=nanloc(i);
b=nanloc(i+1);
if b-a==1,
continue;
else
a=a+1;b=b-1;
end
Tblock = T(a:b,:), %current block
end
Andrei Bobrov
on 10 Jun 2014
l = ~isnan(T(:,1));
k = [l(1);diff(l)] == 1;
ii = cumsum(k);
z = (1:size(T,1))';
out = accumarray(ii(l),z(l),[],@(x)max(sum(T(x,:),2)));
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