writing different datatypes to files

Dear all,

I know there is a lot available already about this problem. I tried several ways but do not see the solution yet :-).

Just to give an example. I create 1 date vector (which I converted from char to string) for 1 year and a random matrix (365,2). I want to write these two variables (containing 3 colomns) into 1 file (tab seperated).

What am I doing wrong? Maybe the solution is via cell arrays only? Thanks in advance.

Here is the code:

% create rand data matrix
A=rand(365,2);

% create Date vector
n1 = datenum(2006, 1, 1);
n2 = datenum(2006, 12, 31);
n3=n1:1:n2;
formatOut='yyyy-mm-dd';
Outdate=datestr(n3,formatOut,'local');

%%% re-format B to string 
for i=1:365; 
    BB(i)=convertCharsToStrings(Outdate(i,:)'); 
end
BB=BB';


%%
fid = fopen('testfile.txt','wt+');
% [nrows,ncols] = size(BB);
% for rwo = 1:nrows
% fprintf(fid,'%s %5.1f %5.1f \n',BB(row), A(row));
% end
fprintf(fid,'%s %5.1f %5.1f \n',BB, A); 
fclose(fid);

Answer 1

[Walter Roberson]

fprintf() "uses up" all of BB before going on to A.

I suggest that you use compose() to construct string objects of the lines and fprintf() those. Or compose() and strjoin() them into one long string and fwrite() it.

[Patrick Laux]

thank you very much.

I was even not aware that compose() exists in Matlab.

Anyway, I could not see how to avoid that compose separates using ",". How to get a tab between the different columns? Thank you once more ...

[Walter Roberson]

compose() does not use comma. But if you want tab then

 A=["a";"b" ]; B=[1 2;3 4]
 compose("%s\t%d\t%d", A, B)

[Patrick Laux]

Yes, you are right. Cannot reproduce the comma-separation again.

Very helpful, thanking you!