MATLAB: Find max of a vector between two indice

maxmax between two indicemin

Hi, I want a code to find the maximum number between two indice of a vector.

I have an indice vector and a data vector . For example my indice vector is :

A=[3 7 13]

and my data vector is:

B=[-5 3 -8 1 -7 2 -9 3 6 2 7 9 -4 2 6]

now the max number between indices 3 and 7 of vector B is number "2" .

and the max number between indices 7 and 13 of vector B is number "9".

So the output should be like a vector named C as follows:

C=[2 9]

I've been thinking on this for hours but haven't found any solution yet 🙁

Tnx in advance.

Best Answer

>> C = arrayfun(@(x) max(B(A(x):A(x+1))),1:length(A)-1)
C =
     2     9

Related Solutions

MATLAB: How to modify a matrix to change the entries >=0 and multiply it by 5 AND to change the entries <0 and add 2 to those entries

Start with "If an entry in B is greater than or equal to zero": You can either run a loop over all elements of B or use "logical indexing":

% Linear indexing:
for k = 1:numel(B)
   if B(k) >= 0
     ...
   end
end

Or two indices for rows and columns:

for r = 1:size(B, 2)
  for c = 1:size(B, 1)
    if B(r, c) >= 0
       ...
    end
  end
end

Or "logical indexing":

index = (B >= 0);
disp(B(index))

Now try to use this to modify B. Use the mentioned terms to search in the documentation and in the internet.

MATLAB: Indexing with intercept for repeating values

a = [1;1;1;2;3;3;4;5;6;7];
b = [1;1;1;1;1;2;3;4;4;4;5;6;7;7];
c = splitapply(@(x){(1:numel(x)).'<=sum(a==x(1))} , b , findgroups(b));
idx=cell2mat(c)
idx = 14x1 logical array
   1
   1
   1
   0
   0
   1
   1
   1
   0
   0

Best Answer

Related Solutions

MATLAB: How to modify a matrix to change the entries >=0 and multiply it by 5 AND to change the entries <0 and add 2 to those entries

MATLAB: Indexing with intercept for repeating values

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