String to number from array

I have a file test.txt which I am reading the content from

the content is such as:

290729 123456

13984 654321

13272 111111

    I have it until here:
    inn = fgetl(thelist);  
    while ischar(inn)
        disp(inn)
        x = strsplit(inn);%I separate the to values in each line
        toNum=x(1,1); %want to get first value and convert it to a number
    
        theNum =double(cell2mat(toNum));%this does not work to convert {'290729'} to a number
    
        class(theNum);%trying to find out what is the type after I tried to make a number out of it
        inn = fgetl(thelist);  
    end

I need to convert this value (such as 290729 or 13984 in this case to a number)

Answer 1

[Konrad]

Hi Nicle

you need str2double() (or str2num()), not double().

double() gives you the UTF(?) code corresponding to the input string. Eg:

double('a') % = 97 or

ans = 97

double('1') % = 49

ans = 49

Conversely:

char([97 49]) % = 'a1'

ans = 'a1'

But:

str2double('1') % = 1

ans = 1

Also str2double() works on cellstrings, no need to for cell2mat():

str2double({'1' '2'}) % = 1 2

ans = 1×2

1 2

Best, Konrad

[Nicle Davidson]

I tried str2num and str2double, I get an error such as:

290729 123456

Error using str2num (line 37)

Input must be a character vector or string scalar.

[Konrad]

Then you allready converted the string to a number (note that for str2num() the input cannot be a cellstring).

Also consider Chunrus answer if your text file exclusively contains numbers as indicated in your question and if you don't need to read the file line-by-line. Then simply using load(filename,'-ascii') might also be a solution.

[Nicle Davidson]

Yes, and thank you for both answers! It helped

Answer 2

[Chunru]

You can use "readmatrix" function:

% Generate the data file
a = [290729 123456
     13984 654321
     13272 111111];
writematrix(a, 'test.txt', 'Delimiter', ' ')
type test.txt

290729 123456
13984 654321
13272 111111

% Read the .txt file
b = readmatrix('test.txt')

b = 3×2

290729 123456 13984 654321 13272 111111