average selected columns with labels

hello all,

I have the attached data. It shows a part of my data. I need to average selected coumns in red only. I need to tell matlab that average electrodes such as ChFP1, ChF7, ChF3, and ChFT7, across subjects and write the resluts in one column at the end of data. How should I do that? I wrote this so far. Thank you in advance. I tried to creat a logical index but could not with a cell array.

if exist(fileName,'file')        
   [num,str]=xlsread(fileName);       %read both str and data
   ch_lables=(str(1,:));            %electrode lables, cell array        
   sub_names=str(:,1);            %subjects names, cell array
 end 

[Sara Boznik]

Hi,

if you know where are red numbers, try this

a=num(:,4)
b=num(:,7)
c=num(:,11)
d=num(:,12)
A=[a;b;c;d]
[n,m]=size(A)
for i=1:1:n
    s(i)=a(i)+b(i)+c(i)+d(i)
    avrg=s(i)/4
    fprintf(fileName(:,15),'%.4f\n',avrg)
end

I wish that this will help you and good luck.

[Elaheh]

Thank you,

No, the order of labes is different in each file, so I need to average across lables of channels that are the same in all files, I need to average ChFP1, ChF7, ChF3, ChFT7, ChFC3) and other combination of electrod lables.

I appreicipate your help.

Zahra

Answer 1

[KSSV]

Use readtable. This is suggested now.

T = readtable(filename) ; 
mean_ChF7 = mean(T.ChF7)

[Elaheh]

Thank you for your reply.

In fact, I need to do this, but it did not work.

T = readtable(fileName) ;

mean_LA = mean(T.ChFP1,T.ChF7,T.ChF3,T.ChFT7,T.ChFC3);

Zahra

[KSSV]

mean_LA = [mean(T.ChFP1) mean(T.ChF7) mean(T.ChF3) mean(T.ChFT7) mean(T.ChFC3)];   

OR

mean_LA = mean([T.ChFP1 T.ChF7 T.ChF3 T.ChFT7 T.ChFC3]);   

[Elaheh]

The problem with these two lines is that they give me 5 values, one for each channel. In fact, I need 22 values one for each participant for these 5 channels. in other words, I need to average across the rows and not across columns.

Please see the attached file.

Zahra

[KSSV]

mean_LA = mean([T.ChFP1 T.ChF7 T.ChF3 T.ChFT7 T.ChFC3],2);   

[KSSV]

OP commented: It works. Thank you so much. What is 2 for?

[KSSV]

2 stands for mean along each row..this what you wanted. DEfault is 1, which is mean along each column.

NOTE: You have to accept/ vote the answer which worked for you. Not that you comment and accept that. :)