I need help finding the mean/avg of my data set

I need help setting a loop to find the mean/avg of my data set. The data set I am looking at is COPNET_x and COPNET_z each of these data contain 3 trials for each subject(49) and the data length output is 6000. What i want to do is to aveg the result of these 3 trials for each subject so i can reduce my 6000 data length. Everything in my code works fine. just need help setting up this mean/avg part.

BMI_numbers = [24.97;34.7;19.01;23.59;18.03;27.4;28.92;19.22;21.42;23.45;21.04;19.55;21.34;32.64;27.75;27.38;26.06;31.48;24.34;22.97;21.14;26.05;22.08;25.19;21.74;18.83;21.04;24.06;27.44;22.77;28.22;30.61;26.07;23.03;25.96;28.52;23.11;31.6;25.66;18.73;28.74;21.5;30.3;28.46;19.95;34.29;21.82;28.95;24.34];
BMI_labels = {'Obese';'Non-Obese'};
subject_numbers = [1:49];
trial_numbers = [1:3];
trial_labels = {'OR1','OR2','OR3'};
counter = 0;
fs = 49;

%% Set up loop structure
for sub = subject_numbers
    for trial = trial_numbers
        counter = counter + 1;
        %% Construct file name and full path
        
        if sub<10
            subject_label = ['0',int2str(sub)];
        else
            subject_label = [int2str(sub)];
        
        end
        
        filename_grf = ['PDS',subject_label,'OR',int2str(trial),'grf.txt']; 

        fullpath_grf = [maindirectory,filename_grf];
       
        
        %% Load data
        if exist(fullpath_grf,'file')~=0
        data_grf = table2array(readtable(fullpath_grf));
      
        
        %% Analyze data
        COPNET_x = data_grf(:,11);
        COPNET_z = data_grf(:,13);
     %%%%%%% How can i find the mean/avg for each subject(3 trials) inside my COPNET data %%%%%%%%%%%%%%%%%%%%%%%%%%%
   for i =1:3
       
        av(:,i) = mean(COPNET_x);
   end
        %GRFNET_x = data_grf(:,5);
        %GRFNET_y = data_grf(:,7);
        
 % BMI < 25 = normal , BMI >25 = overwieght 
        n = length(COPNET_x);
        Rx = max(COPNET_x)- min(COPNET_x); %sway range in AP
        Rz = max(COPNET_z)-min(COPNET_z); % sway range in ML
       
       V_AP = sum(abs(diff(COPNET_x)).*fs)/n; % the average velocity in the AP
       V_ML = sum(abs(diff(COPNET_z)).*fs)/n; % the average velocity in the ML
       
       Velx_max = max(diff(COPNET_x).*fs); % the max velocity in the AP
       Velz_max = max(diff(COPNET_z).*fs); % the max velocity in the ML
       
       Vel_total = sum(sqrt(diff(COPNET_x).^2+diff(COPNET_z).^2).*fs)/n; % The total average velocity COP
       
       Vmax_total = max(sqrt(diff(COPNET_x).^2 +diff(COPNET_z).^2).*fs)/n; % The max velocity COP displacement
        
        results = [Rx Rz V_AP V_ML Velx_max Velz_max Vel_total Vmax_total];
  %How to categorized my data results  
       
        %% Output data
        data_output(counter,:) = [sub BMI_numbers(sub) trial results];
        else
            continue
        end
    end
end

Answer 1

[Cris LaPierre]

I would use groupsummary for this.

Keep your data in a table.

We don't have your data to test with, but here's a simple example.

load patients.mat
data = table(Gender,Age,Weight,Height,Systolic,Diastolic,Location);

% Compute the average of each Gender at each location (similar to each trial for each patient)
avgTbl = groupsummary(data,["Gender","Location"],'mean',["Age","Height","Weight","Systolic","Diastolic"])

avgTbl = 6x8 table
      Gender                Location               GroupCount    mean_Age    mean_Height    mean_Weight    mean_Systolic    mean_Diastolic
    __________    _____________________________    __________    ________    ___________    ___________    _____________    ______________

    {'Female'}    {'County General Hospital'  }        19             38       64.789         129.11          123.47            82.421    
    {'Female'}    {'St. Mary's Medical Center'}        15         36.867       65.533          129.2             121                80    
    {'Female'}    {'VA Hospital'              }        19         38.105       65.211         132.84          120.68            81.895    
    {'Male'  }    {'County General Hospital'  }        20           39.7         68.6          177.9          124.75             85.45    
    {'Male'  }    {'St. Mary's Medical Center'}         9         36.222       69.111         182.78             123            82.889    
    {'Male'  }    {'VA Hospital'              }        18         39.389           70         182.33          123.44            84.389