Another way to do what strsplit does

Hello.

What I am looking for is a way to do what strsplit does since my teacher said he didn't know this function and therefore i could not use it. My code so far is

function [n_nos, graph] = Receber1( fich )
f = fopen(fich, 'r');
if f == -1
    disp('Insucesso ao abrir o ficheiro.');
else
    n_nos = 0;
    graph = [];
    while feof(f) == 0
        line = fgetl(f);
        graph(end+1, :) = str2double(strsplit(strtrim(line)));
        n_nos = n_nos+1;
    end
    fechar = fclose(f);
    if fechar == 0
        disp('Ficheiro carregado com sucesso.');

      else
          disp('Insucesso ao fechar o ficheiro.');
          n_nos = -1;
      end
  end
  end

Thank you so much.

[David Barry]

What a terrible teacher! I suggest he goes back to school. Has he told you what functions he does know and thus you are allowed to use?

[Jan]

Tell your teacher:

doc strsplit

[Sofia Batista]

Indeed!! I am very restrained because of him and my code is working perfectly but i can't use it.

Answer 1

[Jan]

The str2double(strsplit(strtrim(.))) is an overkill here, when a simple sscanf does the same already:

function [n_nos, graph] = Receber1( fich )
f = fopen(fich, 'r');
if f == -1  % IMPORTANT: Stop with an error
  error('Insucesso ao abrir o ficheiro: %s', fich);
end

n_nos = 0;
graph = [];
while feof(f) == 0
   line = fgetl(f);
   graph(end+1, :) = sscanf(line, '%f').';   [EDITED]
   n_nos = n_nos+1;
end
fclose(f);  % No test required
end

If the opening of the file fails, stopping with an error is the only secure reaction. Returning without defining the outputs will produce a strange and confusing error message instead.

General rule: Let the code stop in case of an error to avoid running the program in an undefined state with potentially unpredictable effects.

Closing the file can fail under extremely rare conditions only and will not produce any harm. Only if this happens about 250 times, Matlab cannot open files anymore, but this is detected by checking the -1 after fopen already.

[Sofia Batista]

Hello.

It's actually de perfet way to do it! But it returns

Subscripted assignment dimension mismatch.

Error in Receber1 (line 10)
        graph(end+1, :) = sscanf('%f', line).';

What could i do to change this?

[Jan]

A typo: sscanf(line, '%f') instead of sscanf('%f', line). See the [EDITED] line.

[Sofia Batista]

Thank you !!! It's perfect!