Converting csv of strings into a matrix

Question

I just started using Octave (No money for Matlab :/) and I'm also new to Stack Overflow, so please pardon any error I make with conventions.

Problem: I have a csv of strings like so:

Bob Marley,Kobe Bryant,Michael Jackson,Kevin Hart

I would like to make this into a 1 column matrix (I need it in a matrix so that I can combine it with data that are in other matrices).

My approach: I have tried doing textread, but this gives me a cell array. I tried converting the resulting cell array to a matrix by using cell2mat, but I suspect that I cannot do this because my strings are of varying lengths.

Let me know if any other information is necessary.

HansHirse · Accepted Answer · 2019-03-11 06:16:48Z

1

You can use char arrays using:

fid = fopen('strings.csv');
A = textscan(fid, '%s', 'delimiter', ',');
B = char(A{:})
[rows, cols] = size(B)

Output is the following:

B =
  Bob Marley
  Kobe Bryant
  Michael Jackson
  Kevin Hart

rows =  4

cols =  15

As you can see, the number of columns of B is the maximum length of all "strings" (Michael Jackson, 15). All other "strings" get whitespaces appended.

answered Mar 11, 2019 at 6:16

HansHirse

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1 Comment

Shubham Kumar Over a year ago

This isn't exactly what I was looking for, but this is pretty neat! Thanks :)

Max · Accepted Answer · 2019-03-10 14:08:07Z

0

Considering you are in the directory where you have a file "strings.csv" with the content you mentioned in the question, your code whould look like this:

fid=fopen('strings.csv');
A=textscan(fid,'%s','delimiter',',');
A=A{1};
A=cellfun(@(x) string(x),A,'uni',0);
B=[A{:}];

edited Mar 10, 2019 at 14:08

answered Mar 10, 2019 at 12:27

Max

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4 Comments

Shubham Kumar Over a year ago

I get this error when running your code: warning: the 'string' function is not yet implemented in Octave. Maybe this works for Matlab but not for Octave?

Max Over a year ago

@ShubhamKumar Ok, then I'd like to go back to my original assumption: Does octave even have string matrixes? apparently it has been added to matlab at R2016B and maybe it has not yet been added to Octave. I don't have an installation of Octave so I can't test. This solution works in matlab though.

Shubham Kumar Over a year ago

You might be right, I just resorted to doing cell arrays. Thanks for the help though!

Andrew Janke Over a year ago

Yep, string objects are Matlab-only. cellstrs (cell arrays containing char vectors in their cells) is the right way to do it in Octave.

Andrew Janke · Accepted Answer · 2019-04-20 14:38:59Z

0

If your data is that simple, you can do it in a one-liner. Use fileread to slurp all the data in, and then strsplit to separate the elements, and a ' transpose to convert it to a column vector.

x = strsplit(fileread('myfile.txt'), ',')'

If you end up with spaces around the commas in your data, upgrade to regexp.

x = regexp(fileread('myfile.txt'), ' *, *', 'split')

answered Apr 20, 2019 at 14:38

Andrew Janke

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