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

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.

[Voss]

The error seems to be about the location (or permissions) of the text file, rather than the format of the text file. You should verify that your variables dir and pktFile are defined correctly.

[Raghav Rathi]

The path and everything is correct, I checked the fid and it was not -1.

[Scott MacKenzie]

Try combining dir and pktFile like this:

crc_ = readmatrix(fullfile(dir, pktFile));

BTW, you will likely get NAN where the brackets appear.

[Raghav Rathi]

Thanks Scott, It kind of works but It is also cutting the first and last element.

NaN	255	0	0	6	0	1	0	6	6	6	6	6	NaN

Can you help me with fixing that?

[Raghav Rathi]

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.

Answer 1

[Voss]

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

Answer 2

[Scott MacKenzie]

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);