Re: [sympy] Re: Possible bug in simplify() and a question
Looks like the issue comes from as_numer_denom. I opened https://github.com/sympy/sympy/issues/14622 for this. Aaron Meurer On Thu, Apr 12, 2018 at 8:03 AM, wrote: > To factor/simplify each term, the best way appears to be to use collect and > pass the simplification function as an argument. So I can use the following > syntax: > > spy.collect((n-EY).series(N,x0 = spy.oo).removeO(),N, spy.factor) > > It would be really nice if sympy can support collect() as a member function > of expression objects. Only the part about a possible bug in > sympy.simplify() stands. > > -- > 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 sympy+unsubscr...@googlegroups.com. > To post to this group, send email to sympy@googlegroups.com. > 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/a79426c5-ff10-454b-b79a-f5381d9fbcc7%40googlegroups.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 sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. 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%3D6Jt_-NNHEfM3BtfjLSk2vZFaSsmyvnaKk9-YnE0W2Koig%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
[sympy] Re: Possible bug in simplify() and a question
To factor/simplify each term, the best way appears to be to use collect and pass the simplification function as an argument. So I can use the following syntax: spy.collect((n-EY).series(N,x0 = spy.oo).removeO(),N, spy.factor) It would be really nice if sympy can support collect() as a member function of expression objects. Only the part about a possible bug in sympy.simplify() stands. -- 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 sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. 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/a79426c5-ff10-454b-b79a-f5381d9fbcc7%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[sympy] Re: Possible bug in simplify() and a question
To factor/simplify, each term the best way appears to be to use collect and
pass the simplification function as an argument. So I can use the following
syntax:
spy.collect((n-EY).series(N,x0 = spy.oo).removeO(),N, spy.factor)
Only the part about a possible bug in sympy.simplify() stands.
On Wednesday, April 11, 2018 at 11:28:49 AM UTC-4, div...@umich.edu wrote:
>
> The code below is run in Python 3.6 (Anaconda install), sympy 1.1.1:
> #!/usr/bin/env python
> import sympy as spy
> import sympy.abc as abc
> from sympy import pprint
>
> n = abc.n
> N = abc.N
>
> EY = 2*N*(1-(1-1/(2*N))**n)
> pprint(n-EY)
> print('-'*80, '\n')
> pprint((n-EY).series(N, x0=spy.oo).simplify())
> print('-'*80, '\n')
> pprint((n-EY).series(N, x0=spy.oo))
> print('-'*80, '\n')
> pprint((n-EY).series(N, x0=spy.oo).removeO().simplify())
>
> When the code is run, I see the following output:
>
> ⎛ n⎞
> ⎜ ⎛ 1 ⎞ ⎟
> - 2⋅N⋅⎜- ⎜1 - ───⎟ + 1⎟ + n
> ⎝ ⎝2⋅N⎠ ⎠
>
>
>
>
> ⎛1⎞
> O⎜──; N → ∞⎟
> ⎜ 6 ⎟
> ⎝N⎠
>
>
>
>
>6 54 32 5 4 3 2
>
> n n 17⋅n5⋅n137⋅n n n n7⋅n5⋅n
> n
> ─ - + ─ - + ── - ─── - + ─── - + -
> ──
> 23040 15364608 51211520192 1920 192 384192
> 80
> ── +
> ─── +
> 5 4
>
> N N
>
>
>43 2 32 2
> nn11⋅nn nnnnn
> ─── - ── + ─ - ── - ── + ── - ── ── - ─
> 192 3219232 24 812 44⎛1⎞
> ─ + ── + ── + O⎜──; N → ∞⎟
> 3 2 N ⎜ 6 ⎟
>N N⎝N⎠
>
>
>
>
> ⎛ 43 ⎛ 2 ⎞2 ⎛ 3 2
> ⎞
> n⋅⎝5760⋅N ⋅(n - 1) + 960⋅N ⋅⎝- n + 3⋅n - 2⎠ + 120⋅N ⋅⎝n - 6⋅n + 11⋅n -
> 6⎠ +
>
> ──
>
>
>
>
>
> ⎛ 4 3 2⎞5 4 32
>
> 12⋅N⋅⎝- n + 10⋅n - 35⋅n + 50⋅n - 24⎠ + n - 15⋅n + 85⋅n - 225⋅n +
> 274⋅n
>
> ──
>5
>
> 23040⋅N
>
>
> ⎞
> - 120⎠
> ───
>
>
> simplify() seems to be removing all terms in the asymptotic expansion
> (second printed item). The third printed item is correct and does not use
> simplify(). The fourth print item, which uses simplify() after removing the
> O(), is also correct.
>
> Question: If I want to factor()/simplify() each term in the asymptotic
> expansion, what is the best way to do that?
>
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