How to write multiple outputs to a .txt file?

Hi,

my task is to create a .txt file containing an header (strings +numbers) and a then a matrix, semicolumns separated.

That's my code:

string_outp= [string(app.file_geo), "from", string(from_value), "to", string(to_value), ".geo.txt"];
output_file_name= join(string_outp, "_")
                
fid = fopen(string(output_file_name),'wt'); 
fprintf(fid, '%s\n', app.geo_header); % Writes the header correctly
                
R_mod=vertcat(app.R(from_value:to_value, :)); 
                
writematrix(R_mod, string(output_file_name))% Writes the matrix correctly
fclose(fid);

problem is: the writematrix commanda overwrites the header.

How to write the header and then the matrix?

Thanks in advance,

Alessandro

Answer 1

[Jan]

string_outp= [string(app.file_geo), "from", ...
              string(from_value), "to", string(to_value), ".geo.txt"];
output_file_name= join(string_outp, "_")  
fid = fopen(output_file_name, 'wt'); 
fprintf(fid, '%s\n', app.geo_header); % Writes the header correctly
fclose(fid);

R_mod = vertcat(app.R(from_value:to_value, :));                 
writematrix(R_mod, output_file_name, 'WriteMode', 'append')

So close the file and append the matrix.

Are you sure, that vertcat is needed to contruct R_mod?

[Alessandro Togni]

Thanks for the answer and yes, "vertcat" was not necessary.