Extract max value and corresponding index from a cell into seperate matrixes in a for loop

Hi, I want to extract the index and max value from a cell containing vectors. Currently when I run this code it saves the max stress and index as just a variable rather than a matrix of each vectors max and index.

peak_stress = [];
stress = [];
index = [];

for p=1:numel(sigma)
    peak_stress = [peak_stress, max(sigma{1,p}(1:end))]; %saves max stress as a vector (works fine)
    [stress,index] = max(sigma{1,p}(1:end));  %goal: create a matrix for stress and a matrix for index from sigma cell sigma{1xn}(n,1)
end

[Stephen23]

https://www.mathworks.com/help/matlab/matlab_prog/preallocating-arrays.html

Answer 1

[Jayant]

What I understood from you question is that you want to store the max stress and index.

These values can be appended to the stress and index matrices using the concatenation operator (;).

for p=1:numel(sigma)
    peak_stress = [peak_stress, max(sigma{1,p}(1:end))]; %saves max stress as a vector (works fine)
    [stress,index] = max(sigma{1,p}(1:end));  %goal: create a matrix for stress and a matrix for index from sigma cell sigma{1xn}(n,1)
     % Append the values to the matrices
    stress = [stress; max_stress]; 
    index = [index; max_index];
end

After the loop, the stress matrix will contain the maximum stress values from each vector, and the index matrix will contain the corresponding indices.

I hope this helps.

[Stephen Lesko]

This idea makes sense, but when I tried implementing the code it the stress and index are still being saved as values rather than a matrix.

[Stephen Lesko]

It works with a slight naming change to loop.

for p=1:numel(sigma)
    peak_stress = [peak_stress, max(sigma{1,p}(1:end))]; %saves max stress as a vector (works fine)
    [max_stress,max_index] = max(sigma{1,p}(1:end));  %goal: create a matrix for stress and a matrix for index from sigma cell where sigma{1xn}(n,1)
    % Append the values to the matrices
    stress = [stress, max_stress]; 
    index = [index, max_index];
end

Thank you for the help.