On Jun 15, 2010, at 5:45 PM, Alberto Lusiani wrote:
I would like to get the list of variables of an expression: is that
possible? I searched the help and the web without success. In
practice, given an expression like
expr = parse(text="x^2+y^3")
I would like to have a function such as:
vars(expr)
returns
c("x", "y") or a list like the one returned by formals().
attr(terms(formula(paste("~", "x^2+y^3"))), "variables")
# returns list(x, y)
Regards,
--
Alberto
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David Winsemius, MD
West Hartford, CT
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and provide commented, minimal, self-contained, reproducible code.
