On Thu, Jun 25, 2009 at 10:36 AM, Aaron S. Meurer<[email protected]> wrote: > >> This is our tutorial: >> >> http://docs.sympy.org/tutorial.html >> >> Do you have some ideas how it could be improved? > OK. That isn't too bad. I think we should add a bit for people who > are new to Python. There seem to be quite a few people who use SymPy > who have never used Python before. In particular, maybe a list of > some Python "gotchas" and common pitfalls for people used to other > computer algebra systems. Here are some ideas, based on stuff that I > have noticed: > > 1) = is not equals (use Eq, or set all expressions equal to 0 > 2) == compares exactly, not symbolically (is there a function that > compares symbolically? I know you can do simplify(a-b) and see if it > reduces to 0)
this is in the FAQ too. > 3) variable assignment does not place a relation on variables (this is > already in the FAQ on the wiki) > 4) no implied multiplications > 5) use Rational instead of / to get symbolic fractions Actually, you just need to make sure at least one of the arguments is a sympy expression. I use this to get fractions: S(3)/4 The S(4) makes 4 a sympy integer. > 6) basic use of [ and ( (There was a question about this in the list a > while back) > 7) exponents with ** (most people in other CAS's use ^) > 8) asin, acos, etc. instead of arcsin Right --- python also uses asin. > > Also, the tutorial doesn't seem to mention using dir() to get a list > of all functions and classes and help(func) to get help on a class. And ?<TAB> for docstring. I don't use dir, I use .<TAB> Good points overall, let's incorporate this. Ondrej --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
