How can I write strings and matrices to a .txt file in MATLAB?

Question

I need to write data to a .txt file in MATLAB. I know how to write strings (fprintf) or matrices (dlmwrite), but I need something that can do

Answer 1

I ran into a similar situation adding a header to a csv. You can use dlmwrite with -append to add a single line by setting your delimiter equal to '' as shown below.

str = 'This is the matrix: ';      %# A string
mat1 = [23 46; 56 67];             %# A 2-by-2 matrix
fName = 'str_and_mat.txt';         %# A file name
header1 = 'A, B'
dlmwrite(fName, str, 'delimiter', '')
dlmwrite(fName, header1, '-append', 'delimiter', '')
dlmwrite(fName, mat1, '-append','delimiter', ',')

This produces the following:

This is the matrix: 
A, B
23,46
56,67