what function should I use to download a text file (.txt) ?

I found this code on the Internet

clear all 
sf='D:\Iglin\Matlab\ContData\xrayl.txt'; 
x=load(sf); 
x=sort(x(:)); 
n=length(x);
xmin=x(1); 
xmax=x(n); 
fprintf('Обрабатываем файл %s\n',sf)
fprintf('Объем выборки n=%d\n',n)
fprintf('xmin=%14.7f\n',xmin)
fprintf('xmax=%14.7f\n',xmax)

it gives an error

Error using load
Unable to find file or directory 'D:\Examples\xrayl.txt'.

,

I read that the function load is not suitable for extension files .txt

I found another function on the internet: importdata

clear all % очистить память
sf='D:\Examples\xrayl.txt'; % имя файла данных
x=importdata(sf); % вводим ИД
x=sort(x(:)); % переформатировали столбец и рассортировали
n=length(x); % количество данных
xmin=x(1); % минимальное значение
xmax=x(n); % максимальное значение
fprintf('Обрабатываем файл %s\n',sf)
fprintf('Объем выборки n=%d\n',n)
fprintf('xmin=%14.7f\n',xmin)
fprintf('xmax=%14.7f\n',xmax)

matkad writes

Error using importdata
Unable to open file.

can you tell me if there are any other functions?

[Dyuman Joshi]

Firstly, Is there a file named xrayl.txt in the folder D:\Examples or in D:\Iglin\Matlab\ContData ?

- If there is, does MATLAB have access to read the file? If yes, Try readtable or readmatrix.

- If there is not, then provide the correct path to the file (including the name).

[Walter Roberson]

the code says that the file is at 'D:\Iglin\Matlab\ContData\xrayl.txt' but the error message lists a different location. That is not the code that got executed

[Walter Roberson]

Generally speaking, it is possible to load() some txt files:

• lines that start with % in the file are ignored
• all other lines must only have numbers and delimiters
• must be the same number of numeric entries on each line
• comma delimiter, space delimiter, tab delimiter are all acceptable

So simple blocks of numbers can work with load.

But these days, readmatrix or readtable are generally better as they are more flexible and have better error control.

[Yelena Kokotova]

Thanks very much.

Answer 1

[Sulaymon Eshkabilov]

It really depends what is in the *.txt file and how the data formatted (numerical, text or mix, columnwise, rowise, etc.). See these three examples of *.txt files on how to import or read their data:

FN1 = 'DATA0.txt';
% ALL succeed: load, readmatrix, readtable, importdata, textread. NOTE
% textread() is not recommended --> textscan recommended.
D01 = load(FN1)

D01 = 2×11

0 1.0000 2.0000 3.0000 4.0000 5.0000 6.0000 7.0000 8.0000 9.0000 10.0000 0 0.7513 0.8841 0.9356 0.5431 0.1311 -0.3876 -0.6483 -0.8622 -0.5626 0.0013

D02 = readmatrix(FN1)

D02 = 2×11

0 1.0000 2.0000 3.0000 4.0000 5.0000 6.0000 7.0000 8.0000 9.0000 10.0000 0 0.7513 0.8841 0.9356 0.5431 0.1311 -0.3876 -0.6483 -0.8622 -0.5626 0.0013

D03 = readtable(FN1)

D03 = 2×11 table
    Var1     Var2      Var3      Var4      Var5      Var6      Var7       Var8       Var9       Var10     Var11 
    ____    ______    ______    ______    ______    ______    _______    _______    _______    _______    ______

     0           1         2         3         4         5          6          7          8          9        10
     0      0.7513    0.8841    0.9356    0.5431    0.1311    -0.3876    -0.6483    -0.8622    -0.5626    0.0013

D04 = importdata(FN1)

D04 = 2×11

0 1.0000 2.0000 3.0000 4.0000 5.0000 6.0000 7.0000 8.0000 9.0000 10.0000 0 0.7513 0.8841 0.9356 0.5431 0.1311 -0.3876 -0.6483 -0.8622 -0.5626 0.0013

D05 = textread(FN1)

D05 = 2×11

0 1.0000 2.0000 3.0000 4.0000 5.0000 6.0000 7.0000 8.0000 9.0000 10.0000 0 0.7513 0.8841 0.9356 0.5431 0.1311 -0.3876 -0.6483 -0.8622 -0.5626 0.0013

% ALL succeed BUT importdata reads differently than load, readmatrix,
% readtable, textread
FN2 = 'MN2.txt';
D01 = load(FN2)

D01 = 10×5

17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9 19 26 3 10 17 25 7 9 16 18 6 8 15 22 24 12 14 21 23 5 13 20 27 4 11

D02 = readmatrix(FN2)

D02 = 10×5

17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9 19 26 3 10 17 25 7 9 16 18 6 8 15 22 24 12 14 21 23 5 13 20 27 4 11

D03 = readtable(FN2)

D03 = 10×5 table
    Var1    Var2    Var3    Var4    Var5
    ____    ____    ____    ____    ____

     17      24       1       8      15 
     23       5       7      14      16 
      4       6      13      20      22 
     10      12      19      21       3 
     11      18      25       2       9 
     19      26       3      10      17 
     25       7       9      16      18 
      6       8      15      22      24 
     12      14      21      23       5 
     13      20      27       4      11 

D04 = importdata(FN2)

D04 = 50×1

17 24 1 8 15 23 5 7 14 16

D05 = textread(FN2)  % Not recommended

D05 = 10×5

17 24 1 8 15 23 5 7 14 16 4 6 13 20 22 10 12 19 21 3 11 18 25 2 9 19 26 3 10 17 25 7 9 16 18 6 8 15 22 24 12 14 21 23 5 13 20 27 4 11

% ALL except for textread reads/imports but quite differently and insufficiently well. In this
% case, readtable and importdata do the job very well
% See how textscan works well and reads all data correctly
FN3 = 'DATE_Data.txt';
D01 = load(FN3)

D01 = 5×3

1.0e+03 * 2.0160 0 0.0130 2.0220 0 0.0155 2.0230 0 0.0232 2.0160 0 0.0232 2.0210 0 0.0111

D02 = readmatrix(FN3)

D02 = 5×3

NaN NaN 13.0000 NaN NaN 15.5000 NaN NaN 23.2500 NaN NaN 23.2300 NaN NaN 11.1300

D03 = readtable(FN3)

D03 = 5×3 table
       Var1          Var2      Var3 
    ___________    ________    _____

    18-Feb-2016    00:00:00       13
    18-Feb-2022    00:00:00     15.5
    18-Feb-2023    00:00:00    23.25
    18-Feb-2016    00:00:00    23.23
    18-Feb-2021    00:00:00    11.13

% readtable with options: D03 and DO3B are the same.
OPTIONs = detectImportOptions(FN3);
D03B = readtable(FN3, OPTIONs)

D03B = 5×3 table
       Var1          Var2      Var3 
    ___________    ________    _____

    18-Feb-2016    00:00:00       13
    18-Feb-2022    00:00:00     15.5
    18-Feb-2023    00:00:00    23.25
    18-Feb-2016    00:00:00    23.23
    18-Feb-2021    00:00:00    11.13

D05 = importdata(FN3)

D05 = 5×1 cell array
    {'2016-02-18 00:00:00   13.0' }
    {'2022-02-18 00:00:00   15.5' }
    {'2023-02-18 00:00:00   23.25'}
    {'2016-02-18 00:00:00   23.23'}
    {'2021-02-18 00:00:00   11.13'}

fileID = fopen(FN3);
Format_OPTIONs = '%s %s %f'; % Note the format specs 
D06 = textscan(fileID, Format_OPTIONs)

D06 = 1×3 cell array
    {5×1 cell}    {5×1 cell}    {5×1 double}

fclose(fileID)

ans = 0

D06{1} 

ans = 5×1 cell array
    {'2016-02-18'}
    {'2022-02-18'}
    {'2023-02-18'}
    {'2016-02-18'}
    {'2021-02-18'}

D06{3}

ans = 5×1

13.0000 15.5000 23.2500 23.2300 11.1300

D07 = textread(FN3)   % Fails without specifying the data format in FN3 

Error using dataread
Trouble reading number from file (row 2, field 2) ==>

Error in textread (line 124)
[varargout{1:nlhs}]=dataread('file',varargin{:}); %#ok<REMFF1>

[Yelena Kokotova]

Thanks very much.