Is there a way to only read every third row of a .csv file?

I need my code to read every third row and every column of a .csv file and save it seperately. For example I need the third row, sixth row, ninth row saved but not the first and second rows.

Answer 1

[LO]

import the file and the use logic indexing, double check if it is selecting the right rows, if not just change the index array to index = 1:3:height(forcetest), I am not sure which rows you need

% filename = 'C:\YOURPATH\forcetest.csv';

filename = 'C:\Users\Livio\Downloads\forcetest.csv';

delimiter = ',';

formatSpec = '%f%f%f%[^\n\r]';

fileID = fopen(filename,'r');

dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'TextType', 'string', 'EmptyValue', NaN, 'ReturnOnError', false);

fclose(fileID);

forcetest = table(dataArray{1:end-1}, 'VariableNames', {'VarName1','VarName2','VarName3'});

clearvars filename delimiter formatSpec fileID dataArray ans;

index = 1:2:height(forcetest);

selected_table = forcetest(index,:);

[Petch Anuwutthinawin]

Oh sorry I mistyped, I meant that I need the rows where column 1 is equal to 2. So it would be row 3,6,9 etc but there are multiple points where it misses a 2. Therefore I cannot sort by code.

[LO]

this selects rows with values equal to 2

index = table2array(forcetest(:,1))==2;