Reading large .csv data with 12 million rows

55 views (last 30 days)
Hi all, I have .CSV file with 14 columns and around 12 million rows. I would like to read the data and use it for further analysis. When I use "readtable" command it reads only first two columns with all the information but fails to read other column data. Is there anyway I can read the entire dataset once?
Thanks in advance.
  3 Comments
Ganesh Naik
Ganesh Naik on 16 Dec 2021
Hi Mathieu thanks for your message. I have solved the problem using the following method:
1) I have used "Split CSV" program to split the original CSV files into 12 sub-CSV files (each one million rows)
2) Read each CSV data as:
data1 = readtable('Data-1.csv');
data2 = readtable('Data-2.csv');
.
.
.
data12 = readtable('Data-12.csv');
3) Combine the final file as:
Final_data = [data1; data2;data3; data4;data5; data6;data7; data8;data9; data10;data11; data12];
This created a large table for me (on the fly) at workspace and each time loading the above files dont take much memory. It worked for me, but I believe there maybe better alternative methods.
Mathieu NOE
Mathieu NOE on 16 Dec 2021
ok glad you havefound a workaround ! :)

Sign in to comment.

Answers (1)

Sivani Pentapati
Sivani Pentapati on 1 Dec 2021
Hi Ganesh,
You can try using readmatrix in place of readtable. Other workaround is to convert the 'csv' files into 'mat' files and save them with '-v7.3' option. Please refer to this answer for more information.
  1 Comment
Ganesh Naik
Ganesh Naik on 16 Dec 2021
Dear Sivani, I have solved the problem using SplitCSV method, reading each file and combining the data (I have explained my method above). It worked for me.

Sign in to comment.

Products

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!