Try this:
C3 = ['111'
'010'
'101'
'111'
'110'
'110'
'101'];
C7 = reshape(C3', 7, [])';
C7 =
3×7 char array
'1110101'
'0111111'
'0110101'
Note the 2 transpose operators (') in the ‘C7’ assignment.
