Matching substrings with regexp

I'm trying to identify the subexpressions of a formula such as (real cases much longer):

y = ((a + b) * (c / d) + ( e + f ))

The subexpressions are always separated by pairs of parenthesis as in the example above. It seems like I should be able to use a regular expression with a rule like (intuitively) match "an initial left parenthesis, any characters (but no parenthesis), and a terminating right parenthesis" to get:

(a + b) (c / d) (e + f)

Can anybody suggest a regular expression to do this? Or any way other than a regular expression?

Answer 1

[Guillaume]

subexpressions = regexp(expression, '\([^()]+\)', 'match')

will match any sequence with two brackets enclosing one or more non-bracket.

Answer 2

[per isakson]

AFAIK: That is not possible with Matlab's regular expression. Recursion is needed. With Perl (and other languages it is possible). See http://perl.plover.com/yak/regex/samples/slide083.html

"any way other than" &nbsp See parse_equation