make a matrix out of list

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Nicle Davidson
Nicle Davidson on 16 Oct 2021
Edited: Nicle Davidson on 16 Oct 2021
I have a file which has 4 words such as
It could also be a file with more words, but one word per line.
I would like to after reading from the file, which might could be done with load('file.txt'); command,
make a matrix that is as long as I have words in this file.
so if I have 4 words, then the matrxi H shall be 4 rows long.
Is it a possibility?
  1 Comment
zahra hosaini
zahra hosaini on 16 Oct 2021
i think its possible
declare a parameter like i=1 (showing which row u are in)
make a loop to read all of your file and detecting the end of it as a break
make another loop inside of it for reading each line and detecting the end of it for break(i think it was parameter \0)
as u read the word in second loop put it in your matrix (use another parameter like j=1 for declaring your column and increase it each time you end the second loop)
increase i after getting out of the second loop to move to the next row
  • there will be a warning saying that "your matrix dimention is changing each time you run the file", but thats something that we want and its ok
  • also for your matrix column , u can set a fix number like 10(the longest world length that will be in your file)

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Accepted Answer

DGM on 16 Oct 2021
Edited: DGM on 16 Oct 2021
It's not really clear if you want the contents of the file to be read into an array, or whether you just want a numeric (or other unspecified) array with the same size.
Assuming the first case:
fid = fopen('fruitwords.txt','r');
A = textscan(fid,'%s');
ans = 6×1 cell array
{'banana'} {'orange'} {'apple' } {'peach' } {'pear' } {'cherry'}
If it's the second case, the simple way would be to simply read the file as above and then use the size of A to allocate a new array.
mynewarray = zeros(size(A));
This may be expensive if the file contents are unneeded or cause memory burdens. Trying to accurately and efficiently get line counts might be a bit more complicated otherwise:
  1 Comment
Nicle Davidson
Nicle Davidson on 16 Oct 2021
Let's say I have a file as mentioned above.
Based on this file I have made a such matrix say H in another file:
Explaining what my matrix is: the numbers are ascii for letters, I want to register the positions of where I have capital letters, which have the asciies 65 to 90, in a new matrix say M.
I need to read the matrix H from the file it is stored in, and make a new matrix M which has this in content:
M=(4 5
5 7
5 10
2 12)
The numbers are the positions of capital letters in my H matrix. The point is also that the new matrix M will have same number of rows as I have letters in my word list. (in the example above it was 4) so M needs to have 4 words.
Sorry if I am not so good in explaining the problem. If it helps you can test on the mixAcs.mat file
How can I make a code for this

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More Answers (1)

KSSV on 16 Oct 2021
Read about importdata. You can import the data into MATLAB, the data will be a cell array.
S = importdata('myfile.txt') ;
KSSV on 16 Oct 2021
S is a cell array, you can access the words by S{1},S{2}...S{n}.

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