Also, feel free to use x**2 rather than pow(x, 2) . Your integrand here is not the same as what you put in to the integral calculator.
On Sat, Apr 5, 2014 at 8:38 AM, Matthew Rocklin <[email protected]> wrote: > Symbol should be upper case. Other than that everything is fine. You > also might want to update your sympy version at some point > > In [1]: from sympy import * > In [2]: x = Symbol('x') > > In [3]: d = diff(2 * pow(x, 2), x) > In [4]: d > Out[4]: 4*x > > In [5]: length = integrate(sqrt(1 + pow(d, 2)), (x, 5, 10)) > In [6]: length > Out[6]: -5*sqrt(401)/2 - asinh(20)/8 + asinh(40)/8 + 5*sqrt(1601) > > > > On Sat, Apr 5, 2014 at 4:00 AM, Groover <[email protected]> wrote: > >> Hello, >> >> It's been 20 years since I did any calculus, so please be gentle. :) >> >> Using SymPy 0.7.2 and IronPython 2.7.4. >> >> import sympy >> from sympy import * >> >> # calculate arc length >> x = symbol('x') >> d = diff(2 * pow(x, 2), x) >> print d >> length = integrate(sqrt(1 + pow(d, 2)), (x, 5, 10)) >> print length >> >> This outputs '4*x' as expected then 'zip() argument after * must be a >> sequence, not dictionary-itemiterator'. >> >> I believe the integration is solvable to 75.173 [1], so I assume I have >> an error in my Python and/or SymPy syntax. Can anyone please give me some >> pointers? Thanks! >> >> [1] >> http://www.integral-calculator.com/#expr=sqrt%281%2B%284x%5E2%29%29&ubound=10&lbound=5 >> >> -- >> 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/dfee71bf-d071-44a8-8772-f8d8f75ae855%40googlegroups.com<https://groups.google.com/d/msgid/sympy/dfee71bf-d071-44a8-8772-f8d8f75ae855%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/CAJ8oX-FRBBVxaC71UOpF9pbCeRW-qGWvo3t9YYMyJsvUCfg6ew%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
