MATLAB: How to assign a column vector a name in a matrix while processing multiple files (loop)

column vectorloopmultiple files

Hi, We have 100 .mat- data files containing 5 column vectors. We would like to calculate the average of the 4th column for each of those 100 .mat- data files. Here is a sample of one of our .mat-files:
    0.6797    0.2551    0.2543    0.8308    0.0540
    0.6551    0.5060    0.8143    0.5853    0.5308
    0.1626    0.6991    0.2435    0.5497    0.7792
    0.1190    0.8909    0.9293    0.9172    0.9340
    0.4984    0.9593    0.3500    0.2858    0.1299
    0.9597    0.5472    0.1966    0.7572    0.5688
    0.3404    0.1386    0.2511    0.7537    0.4694
    0.5853    0.1493    0.6160    0.3804    0.0119
    0.2238    0.2575    0.4733    0.5678    0.3371
We tried the following code but we were not able to assign the 4th column the name “HR1” to calculate its mean for each person/.mat- data file.
%%Set path
cd ('N:\backups\Jennifer T.\HR data analysis')
thePath.data = fullfile(pwd,'subject data','PTSDdata','to be added');
thePath.programs = fullfile(pwd,'programs');
addpath(genpath(thePath.data))
% Select multiple Out4 files and open them
cd (thePath.data)               
[F,P]=uigetfile('*.*','MultiSelect', 'on'); 
Re=zeros(length(F),1);
for i = 1:length(F)
    HR1=??(:,4);
    Re(i)= nanmean(HR1)
End
Any suggestions on how to do this? Thank you!

Best Answer

http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F
Also, it is recommended to use the functional form of load:
data = load(F{i});
varnames = fieldnames(data);
firstvar = varnames{1};
HR1 = data.(firstvar)(:,4);
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