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.

[KALYAN ACHARJYA]

data=q3(:,4)/3;
data=[data(1);data(1:end-1)+data(2:end)];
q4=[q3(:,1),data]

Answer 1

[Ameer Hamza]

Are you trying to get something like this

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];

Result

>> 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

[Simon Kibsgaard]

Yes, that works perfectly.

Thank you very much :D

[Ameer Hamza]

I am glad to be of help!

[Simon Kibsgaard]

Hi Again

Now i have an other issue sorting. Hope you can help me again.

I have the data as shown below.

The values in the first column are my node numbers and the values in the third column are the forces in each node. The second column show the dimension of the force.

I need all of the forces to be summed up, but the dimensions cant be mixed. i have also attached a example of the output f that i wish for. My data set is much bigger and therefore ii cant be done by hand.

 30      3 -1.61e+04
  31      3 -1.83e+04
  32      3 -2.09e+04
  33      3 -7.53e+03
  89      3 -1.5e+04
  90      3 -4.14e+04
  91      3 -3.62e+04
  92      3 -3.18e+04
  93      3 -2.88e+04
  94      3 -2.73e+04
  95      3 -2.76e+04
  96      3 -2.96e+04
  97      3 -3.32e+04
  98      3 -3.79e+04
  99      3 -2.82e+04
  30      3 -1.05e+03
  31      3 -1.2e+03
  32      3 -1.37e+03
  33      3   -493
  89      3   -986
  90      3 -2.71e+03
  91      3 -2.37e+03
  92      3 -2.08e+03
  93      3 -1.88e+03
  94      3 -1.79e+03
  95      3 -1.81e+03
  96      3 -1.94e+03
  97      3 -2.17e+03
  98      3 -2.48e+03
  99      3 -1.85e+03
   1      1 1.43e+03
   2      1 1.91e+03
   3      1 1.67e+03
   4      1 1.49e+03
   5      1 1.38e+03
   6      1 1.36e+03
   7      1 1.42e+03
   8      1 1.57e+03
   9      1 1.79e+03
  10      1 2.05e+03
  11      1    752
  23      1 1.39e+03
  24      1 1.88e+03
  25      1 1.65e+03
  26      1 1.47e+03
  27      1 1.38e+03
  28      1 1.37e+03
  29      1 1.45e+03
  30      1 1.61e+03
  31      1 1.83e+03
  32      1 2.09e+03
  33      1    753
  89      1 1.5e+03
  90      1 4.14e+03
  91      1 3.62e+03
  92      1 3.18e+03
  93      1 2.88e+03
  94      1 2.73e+03
  95      1 2.76e+03
  96      1 2.96e+03
  97      1 3.32e+03
  98      1 3.79e+03
  99      1 2.82e+03

  
  
  f=
  30      3 -1.61e+04+(-1.05e+03)
  31      3 -1.83e+04+(-1.2e+03)
  32      3 -2.09e+04+(-1.37e+03)
  33      3 -7.53e+03+(-493)
  89      3 -1.5e+04+(-986)
  90      3 -4.14e+04+(-2.71e+03)
  91      3 -3.62e+04+(-2.37e+03)
  92      3 -3.18e+04+(-2.08e+03)
  93      3 -2.88e+04+(1.88e+03)
  94      3 -2.73e+04+(-1.79e+03)
  95      3 -2.76e+04+(-1.81e+03)
  96      3 -2.96e+04+(-1.94e+03)
  97      3 -3.32e+04+(-2.17e+03)
  98      3 -3.79e+04+(-2.48e+03)
  99      3 -2.82e+04+(-1.85e+03)
   1      1 1.43e+03
   2      1 1.91e+03
   3      1 1.67e+03
   4      1 1.49e+03
   5      1 1.38e+03
   6      1 1.36e+03
   7      1 1.42e+03
   8      1 1.57e+03
   9      1 1.79e+03
  10      1 2.05e+03
  11      1    752
  23      1 1.39e+03
  24      1 1.88e+03
  25      1 1.65e+03
  26      1 1.47e+03
  27      1 1.38e+03
  28      1 1.37e+03
  29      1 1.45e+03
  30      1 1.61e+03
  31      1 1.83e+03
  32      1 2.09e+03
  33      1    753
  89      1 1.5e+03
  90      1 4.14e+03
  91      1 3.62e+03
  92      1 3.18e+03
  93      1 2.88e+03
  94      1 2.73e+03
  95      1 2.76e+03
  96      1 2.96e+03
  97      1 3.32e+03
  98      1 3.79e+03
  99      1 2.82e+03
 

Answer 2

[KALYAN ACHARJYA]

data=q3(:,4)/3;
data=[data(1);data(1:end-1)+data(2:end)];
q4=[q3(:,1),data]

Answer 3

[Stephen23]

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];
[uni,~,idu] = unique(q3(:,1:3));
out = [uni,accumarray(idu,repmat(q3(:,4),3,1))/3]

out = 21×2

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

●

... more rows here