u='If a woodchuck could chuck wood,';
disp(u)
i=find(u>='a' & u<= 'z');     %  find is a very powerful function!
u(i)=setstr(u(i)-('a'-'A'))

v=['Character strings having more than'
   'one row must have the same number '
   'of column just like matrices!     '];
disp(v)
i=find(v>='a' & v<='z');     %  here i is a single index vector into v,
v(i)=setstr(v(i)-('a'-'A'))     %  and matrix keeps the same orientation.