[sage-support] Re: SageMath 8.5 Crash Report

2018-12-30 Thread Murray Eisenberg
Same crash - with kernel panic reported - at end of process of process of verifying when opening sage-8.5-OSX_10.14.2-x86_64.app under macOS 10.14.2. Tried downloads from both UW and MIT, with same result. I've never seen this happen before, even when opening/verifying MUCH larger dmg's (e.g.,

[sage-support] Re: taylor versus series

2018-12-30 Thread Simon King
Hi Peter, On 2018-12-30, Nils Bruin wrote: >> Does this only work in interactive mode? As soon as I try to >> capture it in a function it doesn't work anymore. The syntax R. = QQ[[]] only works interactively. In an interactive session, a preparser is adding some syntactical sugar: sage:

[sage-support] Re: taylor versus series

2018-12-30 Thread Simon King
Hi Nils, On 2018-12-30, Nils Bruin wrote: > In the mean time, you can accomplish your computations without using SR: > > sage: R.=QQ[[]] > sage: (1 - x - sqrt(1 - 6*x + x^2))/(2*x) > 1 + 2*x + 6*x^2 + 22*x^3 + 90*x^4 + 394*x^5 + 1806*x^6 + 8558*x^7 + > 41586*x^8 + 206098*x^9 + 1037718*x^10 +

[sage-support] Re: taylor versus series

2018-12-30 Thread Nils Bruin
On Sunday, December 30, 2018 at 10:30:53 AM UTC-8, Peter Luschny wrote: > > > In the mean time, you can accomplish your computations without using SR: > > sage: R.=QQ[[]] > > sage: (1 - x - sqrt(1 - 6*x + x^2))/(2*x) > > 1 + 2*x + 6*x^2 + 22*x^3 + 90*x^4 + 394*x^5 + ... > > Does this only work in

[sage-support] Re: taylor versus series

2018-12-30 Thread Peter Luschny
> In the mean time, you can accomplish your computations without using SR: > sage: R.=QQ[[]] > sage: (1 - x - sqrt(1 - 6*x + x^2))/(2*x) > 1 + 2*x + 6*x^2 + 22*x^3 + 90*x^4 + 394*x^5 + ... Does this only work in interactive mode? As soon as I try to capture it in a function it doesn't work

[sage-support] Re: taylor versus series

2018-12-30 Thread Nils Bruin
Looking at the implementation, it seems that the ".series" method uses Pynac/Ginac series. A little experimentation seems to suggest that this is not properly wrapped. If we break up the expression in small parts and see how series expansions of the different components combine, we get

[sage-support] Re: taylor versus series

2018-12-30 Thread Peter Luschny
Thank you Simon for your detailed explanations. I'm pretty sure it's a bug. Sage doesn't like little Schroeder either. LittleSchroeder = (1 + x - sqrt(1 - 6*x + x^2))/(4*x) -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe

[sage-support] Re: taylor versus series

2018-12-30 Thread Simon King
PS: On 2018-12-30, Simon King wrote: > It surprises me that .series(x,6) has a pole (after all, LargeSchroeder's > discontinuity in x=0 seems removable), so perhaps it's a bug, but > perhaps it's a feature after all --- I cannot tell from the documentation > if it is intended or not. Here is

[sage-support] Re: taylor versus series

2018-12-30 Thread Simon King
Hi Peter, On 2018-12-30, Peter Luschny wrote: > With Sage 8.4: > LargeSchroeder = SR((1 - x - sqrt(1 - 6*x + x^2))/(2*x)) Putting "SR" around the expression probably isn't needed, as by default x is a symbolic variable (of course this doesn't hold if you have defined x to be something

[sage-support] taylor versus series

2018-12-30 Thread Peter Luschny
Hi, I get with Maple: LargeSchroeder := (1 - x - sqrt(1 - 6*x + x^2))/(2*x); series(LargeSchroeder, x, 6); taylor(LargeSchroeder, x=0, 6); 1+2*x+6*x^2+22*x^3+90*x^4+394*x^5+O(x^6) 1+2*x+6*x^2+22*x^3+90*x^4+394*x^5+O(x^6) Both functions give the same result. Not so with