Str2num error

I am getting the following error:

Error using str2num
Too many input arguments.
Error in b (line 8)
       daystr = str2num(i,'%o');

Here is the portion of the code:

numFiles = 31;
startRow = 1;
endRow = inf;
myData = cell(1,numFiles);

for i = 0:numFiles
    if i<10
       daystr = ['0', str2num (i)];
    else
       daystr = str2num(i);
    end
    filename = ['TS2004.07.',daystr,'.00','.txt'];
    mtx(i) = load(filename);
end

I want to load all text files, 'TS2004.07.0000.txt' to 'TS2004.07.3100.txt'.

Answer 1

[the cyclist]

Don't leave a space between the function name and the parentheses. Also, I think you meant to use num2str here, not str2num. Try

num2str(i)

Answer 2

[Naoki Ishibashi]

Thank you, I solve one error to change num2str(i), but I still have one problem in following,

mtx(i) = load(filename);

I want to put each data into mtx(0) to mtx(31)

[Walter Roberson]

You cannot index a structure at index 0. You will need to add 1, so

mtx(i+1) = load(filename);

See also

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

[Naoki Ishibashi]

Thank you so much, I solve my problem.