I checked through the issue for collection issues and found some, but have a feeling that there are more issues than are there. If you have any deficiencies that you are aware of perhaps you could post something here. You might also check out the pull request that has these functions: https://github.com/sympy/sympy/pull/664
This builds off of the work of pull request https://github.com/sympy/sympy/pull/567 and adds a collect_terms function so a fast gcd can be extracted without destroying the initial structure (and without unecessarily expanding multinomials). These functions also do some things that the current collect and rcollect do not do: This is ok -- it's as simple as you can get: >>> collect(x*sin(x)+x*cos(x)*y,x) x*(y*cos(x) + sin(x)) But there is still more collection that can be done here >>> collect(x*sin(x)+x*sin(x)*y,x) x*(y*sin(x) + sin(x)) >>> collect(x*sin(x)+sin(x)*y,x) x*sin(x) + y*sin(x) >>> collect(x*a+x*b+a+b,x) a + b + x*(a + b) The collect_terms does this exra collection >>> collect_terms(x*sin(x)+x*sin(x)*y, x) x*(y + 1)*sin(x) >>> collect_terms(x*sin(x)+sin(x)*y, x) (x + y)*sin(x) >>> collect_terms(x*a+x*b+a+b, x) a + b + x*(a + b) >>> collect_terms(x*a+x*b+a+b) (a + b)*(x + 1) -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.