Hi, I want to know about the "summation" function used in sympy. The code should be according to the documentation but for summation, As @asmeurer had mentioned earlier to me that- "he is not sure regarding the summation function. That what sympy should be doing with it." https://groups.google.com/forum/#!topic/sympy/z9mZH10UuY0
Right now the documentation does not match with the way summation is done right now. I guess we have choices for implementing the summation function(which i am noticing are the same as Aaron mentioned in issue #5822 https://github.com/sympy/sympy/issues/5822) 1. Following the way as the documentation says "taking all integer values from ``start`` through ``end``". which implies summation like summation(exp(a*x), (x, 1.2, 1.5)) would result in a value of zero. (since no integer value is included between 1.2 and 1.5) I think this would not be the best way to go. As the this would result in many function summation to result in a value even if the summation should not exist. 2. Following the way sympy is going right now i.e evaluate the the summation for general expression and than substituting the value of lower and upper limit. (I don't think it would be a good way to go.) 3. Following the way the Wolfram Alpha is doing i.e evaluating making the lower limit not to be a fraction for evaluating the summation. I would like to work on the issue #5822 . On Friday, January 23, 2015 at 8:36:18 AM UTC+5:30, Aaron Meurer wrote: > > See https://github.com/sympy/sympy/issues/5822 for a discussion on this. > I'm not sure what convention SymPy should take, but the documentation ought > to match it. > > Aaron Meurer > > On Thu, Jan 22, 2015 at 7:56 PM, Gaurav Dhingra <[email protected] > <javascript:>> wrote: > >> Hi all >> >> I ran the following the following code >> >> In[10]: simplify(summation((k), (k, 2, 4.7))) == simplify(summation((k), >> (k, 2, 4.4))) >> Out[10]: False >> >> I read the documentation of summation function, so according to it the >> summation includes all the integer values from start to end. But does not >> seem to follow it. >> >> Is this a bug. ? >> >> -- >> 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] <javascript:>. >> To post to this group, send email to [email protected] <javascript:> >> . >> 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/697cda0a-62db-411e-bf10-a9d601bbcb69%40googlegroups.com >> >> <https://groups.google.com/d/msgid/sympy/697cda0a-62db-411e-bf10-a9d601bbcb69%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > -- 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/b6924d03-fbbf-4c63-ad87-92a9ac5e0c12%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
