Saving data to a file and getting giberish

I am trying to save two columns of numbers to a file, right now its a txt file but when I open the file its just a bunch of nonsense.

my code is below

fileID = fopen(filename);

a = textscan(fileID,'%u');

b = {a,a};

c =[b{1,1}{1,1},b{1,2}{1,1}];

d = double(c);

save('test.txt', 'd')

Answer 1

[Image Analyst]

That's the proprietary MAT file format. If you want text, try the -ascii option

save('test.txt', '-ascii', 'd')

or else use fopen(), fprintf(), and fclose().