Mean of matrices calculation

I have 200 .vec files which represent 200 time instances. In each file I have a matrix 'u', velocity, which is 79by49 matrix. I need to find the time average velocity field. Therefore I need to find the average of all the u matrices of all the 200 time instances.

How can I find the mean of all 200, 79by49 u matrices in form of a new 79by49 matrix ?

I would appreciate any suggestions.

Here is my code so far.

thank you,

Tara

clear all               % clears all the variables which were open from prev. tasks
clc                     % clears all the previous commands
close all                 
files = dir('*.vec');

I = 79; 
J = 49;  
ScaleFactor = 5.09475;  %px/mm 
dt = 50e-6;             %sec
Fs = 1000;              %Hz
tf = 0.2;               % 0.2s is the toal time taken to obtain the data for all datapoints ;  
ti = 0.001;             % is time between two data files 
 t = ti:ti:tf;          % describes the full time taken to capture all the 200 files including time intervals 
b1 = 153.6876;          % length of the plain cylinder    
b2 = 153.6876;          % length of the stepped cylinder 

u1 = zeros(200,1);      % introducing a 200by1 matrix for all the u results at location 1(mid-span)  
u2 = zeros(200,1);      % introducing a 200by1 matrix for all the u results at location 2(b1/4 above mid-span)
u3 = zeros(200,1);      % introducing a 200by1 matrix for all the u results at location 3(b1/4 below mid-span)
v1 = zeros(200,1);      % introducing a 200by1 matrix for all the v results at location 1(mid-span)  
v2 = zeros(200,1);      % introducing a 200by1 matrix for all the v results at location 2(b1/4 above mid-span)
v3 = zeros(200,1);      % introducing a 200by1 matrix for all the v results at location 3(b1/4 below mid-span) 


for p = 1:length(files)
    data_vec = dlmread(files(p).name, ',',1,0);   
    
    cntr = 1;
    K = 1;
    L = 1;
    
    x_grid = (data_vec(1:I,1))/ScaleFactor; %mm
    y_grid = (data_vec(1:I:end,2))/ScaleFactor; %mm
    u = zeros(I,J);
     v = zeros(I,J);
    
    while L<=J
        u(K,L) = data_vec(cntr,4)/(ScaleFactor*dt*1000); %m/s
        v(K,L) = data_vec(cntr,3)/(ScaleFactor*dt*1000); %m/s
        cntr = cntr+1;
        K = K+1;
        if K-1 == I
            K = 1;
            L = L+1;
        end
    end
    
     
     u1(p) = u(16,24);   % to save all the u(16,24) or u at location 1 in the u1 matrix         
     u2(p) = u(16,12);   % to save all the u(16,12) or u at location 2 in the u2 matrix     
     u3(p) = u(16,36);   % to save all the u(16,36) or u at location 3 in the u3 matrix     
    
     v1(p) = v(16,24);   % to save all the v(16,24) or v at location 1 in the v1 matrix  
     v2(p) = v(16,12);   % to save all the v(16,12) or v at location 2 in the v2 matrix  
     v3(p) = v(16,36);   % to save all the v(16,36) or v at location 3 in the v3 matrix  
    
    
    [x,y] = meshgrid(x_grid,y_grid);
    x = x';
    y = y';  
end

[darova]

What about this?

A = 0;
for i = 1:200
    A = A + A1;
end
A = A/200;

[Tahereh Goorangi]

Hi Darova,

thank you for your reply.

your answer helped a lot.

[darova]

you are welcome

Answer 1

[Sai Sri Pathuri]

Hi,

You can find the sum of all velocity matrices and find the average as

% average = (velocityMatrix1 + velocityMatrix2 + ... + velocityMatrix200)/200;

To find the sum and mean of velocity matrices, you may use for loop as mentioned by darova

sum = 0;
for i = 1:200
    % load the file corresponding to ith time instant. You may uncomment below code if your files are named u1.vec, u2.vec, ... and so on
    % filename = append("u",string(i),".vec");
    % load(filename);
    sum = sum + u;
end
average = sum/200;

[Tahereh Goorangi]

Hello there,

Thank you so much for the reply.