edit large CSV file before reading it to a table

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sani
sani 2021-5-6
评论： sani 2021-5-6
hi,
I have a very large (16Gb) CSV file that contains one column with data separated by semicolumn.
I only need 2 columns from this data, but I cannot read it first since the memory is running out (I have 16Gb ram).
Is it possible to somehow separate the semicolumn to a column and read only the data I need (which is 2/6 columns)?
  2 个评论
Stephen23
Stephen23 2021-5-6
编辑：Stephen23 2021-5-6
How do you expect to get "...2 columns from this data..." from a "...CSV file that contains one column with data..." ?
sani
sani 2021-5-6
It contain one column but the data is saperated in ';'.
basicly I needed to saperate it first and than to read only whats relevant for me.
see wallter solution, it was actually really halpful.

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Walter Roberson
Walter Roberson 2021-5-6
https://www.mathworks.com/help/matlab/ref/matlab.io.text.delimitedtextimportoptions.html
Use 'delimiter', ';', and 'SelectedVariableNames' with a vector that is the two column numbers.
  1 个评论
sani
sani 2021-5-6
thank you very much walter!
for some reason not only that it maneged to read the data, it also write it really fast in readtable() function. much faster than other smaller files I'm reading.

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