MATLAB: Find, sort and assign values in matrix

Hi im very new to matlab and cant get the following input to find and sort correctly.

An help is much appereciated 🙂

%input 
q3 =    
    1.0000    2.0000   90.0000    4.9424
    2.0000    3.0000   91.0000    4.3018
    3.0000    4.0000   92.0000    3.7912
    4.0000    5.0000   93.0000    3.4618
    5.0000    6.0000   94.0000    3.3465
    6.0000    7.0000   95.0000    3.4566
    7.0000    8.0000   96.0000    3.7815
    8.0000    9.0000   97.0000    4.2892
    9.0000   10.0000   98.0000    4.9293
   10.0000   11.0000   99.0000    5.6382
    ...
        
    
  %wanted output       
q4=    
    1.0000    (4.9424/3)
    2.0000    (4.9424/3)+(4.3018/3)
    3.0000    (4.3018/3)+(3.7912/3)
    4.0000    (3.7912/3)+(3.4618/3)
    5.0000    (3.4618/3)+(3.3465/3)
    6.0000    (3.3465/3)+(3.4566/3)
    ... 
    98.0000   (4.9293/3)
    99.0000   (5.6382/3)

The numbers is column 1, 2 and 3 are the numbers of my nodes. Each row is the nodes of a triangle and the area of that triangle.

Now need the area of each triangle to be divided out onto each node of that triangle. At last i need all of the areas that are divided onto node number 1 to be sumed up and so forth for each node.

q3 = [ 1.0000 2.0000 90.0000 4.9424 2.0000 3.0000 91.0000 4.3018 3.0000 4.0000 92.0000 3.7912 4.0000 5.0000 93.0000 3.4618 5.0000 6.0000 94.0000 3.3465 6.0000 7.0000 95.0000 3.4566 7.0000 8.0000 96.0000 3.7815 8.0000 9.0000 97.0000 4.2892 9.0000 10.0000 98.0000 4.9293 10.0000 11.0000 99.0000 5.6382]; q_ = q3(:,1:3); vals1 = unique(q_); vals2 = zeros(size(vals1)); for i = 1:numel(vals1) idx = any(q_==vals1(i),2); vals2(i) = sum(q3(idx,4)); end q4 = [vals1 vals2/3];

>> q4 q4 = 1.0000 1.6475 2.0000 3.0814 3.0000 2.6977 4.0000 2.4177 5.0000 2.2694 6.0000 2.2677 7.0000 2.4127 8.0000 2.6902 9.0000 3.0728 10.0000 3.5225 11.0000 1.8794 90.0000 1.6475 91.0000 1.4339 92.0000 1.2637 93.0000 1.1539 94.0000 1.1155 95.0000 1.1522 96.0000 1.2605 97.0000 1.4297 98.0000 1.6431 99.0000 1.8794

Best Answer