Comment #5 on issue 2316 by hacm...@gmail.com: limit involving multi-arg function (polygamma) fails
http://code.google.com/p/sympy/issues/detail?id=2316

I'm wondering what is involved in fixing this. I got a similar error ("NotImplementedError: MRV set ...") when trying to evaluate

num = binomial(2*n,n)/(n+1)
denom = 4**n/sqrt(pi*n**3)
limit(num/denom, n, oo)
<NotImplementedError>

If I tell sympy to use the factorial definition of the binomial coefficient, I get the right answer:
num = factorial(2*n)/factorial(n)**2/(n+1)
denom = 4**n/sqrt(pi*n**3)
limit(num/denom, n, oo)
1

What's slightly special about this case is that the error relating to several variables does not really apply. Since I am evaluating a quantity that, while defined in terms of a binomial coefficient, is really a univariate expression. So my questions are twofold:

1. what is involved in getting full multivariate support?
2. if that is too difficult, is it worth attempting to simplify expressions that are actually univariate? I believe that .free_symbols would work here)

--
You received this message because this project is configured to send all issue notifications to this address.
You may adjust your notification preferences at:
https://code.google.com/hosting/settings

--
You received this message because you are subscribed to the Google Groups 
"sympy-issues" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to sympy-issues+unsubscr...@googlegroups.com.
To post to this group, send email to sympy-issues@googlegroups.com.
Visit this group at http://groups.google.com/group/sympy-issues.
For more options, visit https://groups.google.com/groups/opt_out.

Reply via email to