On Feb 23, 2011, at 3:32 PM, Alexander Eberspächer wrote: > Hello, > > On Wednesday, February 23, 2011 10:13:24 PM UTC+1, asmeurer wrote: > I agree. 1 + x + x**2/2 + O(x**3) is not a series. A series would be > something like summation(x**n/factorial(n), (n, 0, oo)). We don't have > anything like that implemented (though it would be awesome if we did). > > +1. Extremely useful. Also: +1 on Laurent series!
Do you know of any algorithms do to this? The only thing I can think of is to implement (for example with Taylor series) the most common cases (like exp(x), sin(x), etc.) and also the formulas for multiplying, adding, etc. series. But maybe there is some more general method that involves generating and solving some recurrence relations. > > The expansion 1 + x + x**2/2 + O(x**3) would be called "truncated Taylor > series of order 2". > I think the answer is just to be clear in the docstring. > > Yes. However, if in doubt, I think the standard maths terminology is to > prefer over the terminology used in other computer algebra systems. Another thing to consider is that the name "series" already exists in SymPy, and has for some time, so any changing would be a break in compatibility. But I agree that we should only use other CASs as guides, not as rules for what we should do. Aaron Meurer > > Greetings > > Alex -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
