Can you help with logic behind this problem? Iterations

I have a cell array as follows:

no. of columns = 3 and no. of rows = 800
First Column - Serial No
Second Column - Character
Third Column - Number

cell = {1  'N'  1.2 ; 2  'B' 3.2 ; 3 'D' 5.3 ; 1  'N'  1.2 ; 2  'A' 3.2 ; 3 'G' 5.3 ; 1  'E'  1.2 ; 2  'F' 3.2 ; 3 'G' 5.3 ; 1  'N'  1.2 ; 2  'C' 3.2 ; 3 'D' 5.3 ; 1 'H' 1.2 ; 2 'B' 3.2 ; 3 'D' 5.3 ; 1 'N' 1.2 ; 2 'B' 3.2 ; 3 'E' 5.3 ....................}

In second column character 'N' repeats after certain entries (rows).

I want to add the numbers in third coulmn from the row with 'N' in second column till the rows before next 'N' appears in second row.

[Azzi Abdelmalek]

What should be the result?

[Jan]

"cell" is an important Matlab command. Using this term as a name of a variable shadows the built-in function and this causes troubles frequently.

Answer 1

[Azzi Abdelmalek]

idx1=find(cellfun(@(x) isequal(x,'N'),cell(:,2)));
idx2=[idx1(2:end)-1; size(cell,1)];
for k=1:numel(idx1)
  h{k}=cellfun(@(x) x+cell{idx1(k),3},cell(idx1(k):idx2(k),3));
end
h=cell2mat(h');
cell(:,3)=num2cell(h(:));

[Jan]

What about this for getting idx1:

idx1 = find(strcmp(c(:, 2), 'N'));