There may be more elegant ways to read the file, but I often prefer to use textscan to read a text file into a cell array of strings. This lets me experiment with parsing to make sure I get it right.
The cyc values vary between 1 and 260, but some values are missing in every set. For every cyc value I select the corresponding lines in the data array and calculate the mean.
fid = fopen('rata2_j1.txt');
lines = textscan(fid,'%s', 'Delimiter', '\n','HeaderLines' ,1);
fclose(fid);
lines = lines{1}; % Cell array of strings, one per line
N = length(lines);
cyc = zeros(N,1);
data = zeros(N,6);
for i = 1:N
A = sscanf(lines{i},'%f'); % Parse line to array of 7 dounbles
cyc(i) = A(1);
data(i,:) = A(2:7);
end
averages = zeros(260,4);
for i = 1:260
averages(i,:) = mean(data(cyc==i,3:6),1);
end
Note that I have calculated averages for each cyc value and column separately. If you want to average all four columns, add the line:
average = mean(averages,2);
