Isletter2

Enhancement of the built-in function ISLETTER

Description

For a string STR, ISCAPLETTER(STR) returns a vector with 1 for capital letters, -1 for small letters and 0 otherwise.

  ISLETTER2(STR,'all') returns 1 if all components of STR are letters.

  ISLETTER2(STR,'any') returns 1 if any component of STR is a letter.

  Ex:
      str='Matlab R12.1';

      is_isletter=isletter(str);
      is_isletter2=isletter2(str);
      is_isletter2_all=isletter2(str,'all');
      is_isletter2_any=isletter2(str,'any');

      is_isletter =
           1 1 1 1 1 1 0 1 0 0 0 0

      is_isletter2 =
           1 -1 -1 -1 -1 -1 0 1 0 0 0 0

      is_isletter2_all =
           0

      is_isletter2_any =
           1

• MATLAB release: MATLAB 6.1 (R12.1)

[Jos x@y.z]

The help can be improved (ISCAPLETTER?, Ex?)

I think:
  q = isletter(str) ;
  q = q - 2*(str==lower(str) & q) ;
is faster then ismember twice.

Why the double tilde (~~)?

Jos

[Jérôme Briot]

Thanks for the review, Jos.

I corrected the typo in the help and I removed the double tilde.

Your code is more efficient than mine.

Jérôme