How to read a large CSV in chunks;

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ariane
ariane 2018-8-23
回答： Rishi Binda 2018-8-28
I have the following code which filters a very large CSV.
opts = detectImportOptions('Z_EnergySequence.dat');
data = readtable('Z_EnergySequence.dat',opts);
tol = 1e-6;
filter = 4.125;
filterreddata = data(abs(data.X - filter) < tol, :);
filteredions = data(ismember(data.IonN, filterreddata.IonN),:);
filteredions(1:2:end,:)= [];
writetable(filteredions, 'Published/Z_EnergySequence1.csv');
I think I may be getting errors in the data processing. Is there a way in which I can read the whole CSV in chunks and output to the same file?
  1 个评论
Jan
Jan 2018-8-23
编辑：Jan 2018-8-23
I think I may be getting errors in the data processing
This seems to be a pure speculation. Do not try to fix not existing problems.

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回答（1 个）

Rishi Binda
Rishi Binda 2018-8-28
If you want to read specific range of the generated csv file you can use one of the following :
  • csvread
  • dlmread
  • xlsread

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