How to read array from a text file into each row of a matrix.

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Hi,
I am trying to read a text file which contains arrays in each line. I am trying to read each line into new row of a matrix.
The text file is in the following format.
[255, 255, 0, 0, 11, 0, 1, 0, 11, 11, 11, 11, 11, 11]
[255, 255, 0, 0, 18, 0, 1, 0, 18, 18, 18, 18, 18, 18]
[255, 255, 0, 0, 12, 0, 1, 0, 12, 12, 12, 12, 12, 12]
[255, 255, 0, 0, 10, 0, 1, 9, 10, 218, 10, 138, 10, 58]
[255, 255, 0, 0, 4, 0, 1, 0, 4, 4, 4, 4, 4, 4]
.
.
.
I tried to do it using readmatrix but I am getting the following error.
Error using readmatrix (line 158)
Unable to find or open file. Check the path and
filename or file permissions.
Error in decodePyramid (line 9)
crc_ = readmatrix(dir+pktFile);
Any help is appreciated.
Thank you.
  5 Comments
Raghav Rathi
Raghav Rathi on 26 Feb 2022
if you look at the text file, each line contains 14 elements
[255, 255, 0, 0, 6, 0, 1, 0, 6, 6, 6, 6, 6, 6]
But they way you mentioned is skipping the first and last elements.
NaN should be the '[' and ']' but there is a 225 and 6 missing as well.

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Answers (2)

Voss
Voss on 26 Feb 2022
fid = fopen('input.txt');
data = str2num(fread(fid,'*char').');
fclose(fid);
disp(data);
255 255 0 0 11 0 1 0 11 11 11 11 11 11 255 255 0 0 18 0 1 0 18 18 18 18 18 18 255 255 0 0 12 0 1 0 12 12 12 12 12 12 255 255 0 0 10 0 1 9 10 218 10 138 10 58 255 255 0 0 4 0 1 0 4 4 4 4 4 4

Scott MacKenzie
Scott MacKenzie on 26 Feb 2022
OK, this should work. First, combine dir and pktFile using the fullfile function. Read the data using readtable, then restore the 1st and last columns to numeric values (by removing the brackets and converting to double). If you want the data in a plain matrix, follow with table2array:
T = readtable(fullfile(dir, pktFile));
T.Var1 = cellfun(@(x) str2double(x), erase(T.Var1, '['));
T.Var14 = cellfun(@(x) str2double(x), erase(T.Var14, ']'));
crc_ = table2array(T);

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