[sage-devel] Re: Reason for the is_zero() method?

2018-07-21 Thread Nils Bruin
On Saturday, July 21, 2018 at 11:28:44 AM UTC-7, Jeroen Demeyer wrote: > > I was benchmarking some code (in particular the density() method of > matrices) and noticed code of the form > > if not x.is_zero(): > > however, that's a lot slower than doing just > > if x: > > So, this makes me

[sage-devel] Announce: IMA workshop "COIN fORgery" (open source mathematical optimization tools), Oct 15-19, 2018

2018-07-21 Thread Matthias Koeppe
This workshop may be of interest to those who are working on features related to mathematical optimization in Sage. "COIN fORgery: Developing Open Source Tools for Operations Research" will be held at the IMA (Institute for Mathematics and its Applications, University of Minnesota) October 15

[sage-devel] Reason for the is_zero() method?

2018-07-21 Thread Jeroen Demeyer
I was benchmarking some code (in particular the density() method of matrices) and noticed code of the form if not x.is_zero(): however, that's a lot slower than doing just if x: So, this makes me wonder: what is the reason for the is_zero() method? Are there classes where "x.is_zero()" is

[sage-devel] Re: SM_Carter-Penrose_diag.ipynb

2018-07-21 Thread Eric Gourgoulhon
Hi, It looks very obscure and is certainly nothing that could be executed in > any version of SageMath (neither in command line nor in the notebook). > > Indeed it was not very clear... Aishen was actually referring to the Carter-Penrose diagram of the manifold examples

[sage-devel] Re: 8.3.rc1: issue with sage banner

2018-07-21 Thread David . Coudert
Fixed: I had to ensure that languages variables (LANGUAGES, LC_ALL, LANG) are well set. This was somehow done by default with previous versions of the system. Best, Le vendredi 20 juillet 2018 14:45:33 UTC+2, david@inria.fr a écrit : > > I just did a fresh install of sagemath (git clone …)