It looks like the meijerg algorithm gives the better form: In [33]: integrate(tan(x), x, meijerg=True) Out[33]: -log(cos(x))
Aaron Meurer On Fri, Feb 19, 2016 at 2:21 PM, Ondřej Čertík <[email protected]> wrote: > On Fri, Feb 19, 2016 at 8:45 AM, Aaron Meurer <[email protected]> wrote: >> trigsimp() will convert the sin to cos. To remove the negative and >> square, you'll have to use expand_log(force=True), which gives a >> complex constant (which can be ignored, since this is an integral). >> >> It would definitely be better if integrate at least gave log(1 - >> sin(x)**2) so that the result is real. > > Here is a code that does this: > > In [1]: expand_log(integrate(tan(x), x).trigsimp(), force=True) > Out[1]: -log(cos(x)) - I*pi/2 > > Ondrej > >> >> Aaron Meurer >> >> On Fri, Feb 19, 2016 at 8:07 AM, Carsten Knoll <[email protected]> wrote: >>> I want to calculate the antiderivative for tan(x) >>> >>> In [4]: x = sp.Symbol('x', real=True) >>> >>> In [5]: sp.integrate(sp.tan(x), x) >>> Out[5]: -log(sin(x)**2 - 1)/2 >>> >>> >>> This result is technically correct, but I would (for didactic purposes) >>> prefer something like >>> >>> -log(cos(x)). >>> >>> How can I achieve this? >>> >>> Thanks. >>> Carsten. >>> >>> -- >>> 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 https://groups.google.com/group/sympy. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/sympy/56C71381.4090204%40gmx.de. >>> 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 https://groups.google.com/group/sympy. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/sympy/CAKgW%3D6JnGtQ2-40XA2kSyD%3D7J%3D1futiJx2z7ocr53T0UrW%3DpLw%40mail.gmail.com. >> 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 https://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/CADDwiVA%3DK7zMNjEYizfFDzqgf_2J6OjcHBC8wJ8amBcDr%2BKcVw%40mail.gmail.com. > 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 https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6J0eBE-he98HrabrC5y0ipNCLpy7BAkiZY17X4vDA679w%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
