Reading in a text file with numbers and strings into a cell array

Hi everyone, I've attached the text file here, and what I'm trying to do is read in line by line and put the strings and numbers into a cell array.

Ideally I would like to read this into a cell array that looks like this:

First Index

0 1 6 2 3

1 3 2 4 0

2 1 6 4 7

3 0 1 4 7

4 0 5 6 1

5 0 1 2 3

...etc

(I just put a bunch of spaces between the numbers but I actually need them in different cells)

(Its okay if the words/strings are all in the same cell because I'm going to try to find a way to skip that anyways)

Can anyone please assist with this? and do you think you can explain how you make it return to the next cell row after 5 columns?

When I try a code like this, I just get all the data in one cell:

t = readtable('index.txt', 'ReadVariableNames', false);

[Stephen23]

@Akana Juliet: do you have any control over the file format? If those words "First", "Second", etc. were replaced with integers e.g. "Index 1", "Index 2", etc. then this task would probably be a lot easier.

[Akana Juliet]

@Stephen Cobeldick Yes, I can control the Titles of each category but I can't change the format of the numbers beneath the titles

Answer 1

[JJ Lamb]

For reading the file in, something like this should work. This will output one cell, but you can index that cell into it's subparts.

fid = fopen('index.txt','r');
t = textscan(fid,'%s','delimiter','\t');
fclose(fid);

You will need to convert the strings to numeric types. Doing what I did below changes the labels like "First Index" to empty values, so you'll want to make sure you save those from the initial t variable.

t2 = t;
for n = 1:length(t2{1})
    t2{1}{n} = str2num(t2{1}{n});
end

Last, the easiest way to solve the column problem is being careful with your indexing, if you know how many total columns you have. This following block will take the first row and turn it into the format you want.

reshape(t2{1}{2},5,4)';

First it reshapes the 1x20 row matrix into a 5x4 matrix and then transposes it. Reshape goes down the column first, so you simply transpose once that's done.

Hopefully you can combine these steps to get a result that works for you.

[Akana Juliet]

@JJ Lamb This is the closest I've gotten to what I need! I can't thank you enough!! I just have one more question if you don't mind. I was wondering what type of tweaks would I need to make to this to also use this same code for reading a very similar text file except with hexadecimal values instead of decimal values?

***Sorry, one more additional question too, How can I make this produce more than just 4 rows? When I tried to change the 4 in the reshape line it said:

"Error using reshape

To RESHAPE the number of elements must not change."

[JJ Lamb]

The textscan function should just read everything in as a string. To use hexidecimal instead of doubles (decimal values), that part you would probably change is the str2num command to something that can convert a string to hexidecimal.

This link here should give you some options. The best of for you probably depends on how you have things formatted.

Like the error says, the number of elements can't change in a call to reshape. In the line I wrote, I took a 1x20 matrix (20 elements) and changed it to a 5x4 matrix (20 elements) and then transposed it. You just need to make sure that your number of elements doesn't change. If you want to do more than 4 rows, your original row matrix would need to be longer.

[Akana Juliet]

@JJ Lamb Oh I see, thank you for explaining that to me. is there a way to avoid the transpose and just tell the computer 5 columns/values then return, repeat? Because I can't really edit the text file

[JJ Lamb]

I would check out the documentation for reshape to see if it can do what you want.

Because you have several lines that are mixed in with text, your best option might be to use some combination of a for loop with an if statement something like "if isnum()..." and then append the results together as you go. I don't know if you would be able to do everything in one line.