If A is any matrix, when you type A(:), it always concatenates column wise irrespective of it's dimensions. If you want to change it's behavior like you mentioned in my case row concatenation in a long row; you have to transpose the matrix and then use :.
F = [0.1233 0.0801 0.0001
0.4082 0.2002 0.0002] ;
F = F' ;
FF = F(:) ;
You put a if condition and proceed with transpose.
if size(F,1) < size(F,2)
F = F' ;
FF = F(:) ;
end