I'm trying to integrate ln(x-y) dy, but the result I get from SymPy is very different from Maple's answer. Here is what I get when I integrate in SymPy: In [2]:
integrate(ln(x-y), y) Out[2]: -x*log(-x + y) + y*log(x - y) - y When I try to differentiate this, i get something very different from ln(x-y): In [3]: diff(-x*log(-x + y) + y*log(x - y) - y, y) Out[3]: -x/(-x + y) - y/(x - y) + log(x - y) - 1 Is this a bug in SymPy, or a user error? When i differentiate the answer I get when I integrate using Maple, i get the expected result ln(x-y) In [4]: diff(-ln(x-y)*(x-y)+x-y, y) Out[4]: log(x - y) An IPython Notebook with an example can be found here: http://nbviewer.ipython.org/gist/FSund/d3b3f7f590db0e72e2e2 I'm using Python 3.4.3 (Anaconda 2.3.0 (64-bit)), and IPython 4.0.0. -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/a74a1e86-7fa2-4d98-92fd-85cc7c1472f3%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
