To the community of Sagemath developpers
I was using mathematica because for years Sagemath was running only in a Virtual machine. Then I discover that Sagemath was now easy to install and more than that that it was able to solve an optimization problem that Mathematica was unable to solve without a little help.So I have decided to try to convince my fellow collegues economists to use Sagemath -- with a link to R, I hope it will not be too difficult. It's the reason why, as I am not an expert in programmation I ask so much question. Thanks all for your kind answers. I know it's not the place to publish such a text but I want every contributors to know that many peoples are aware of your efforts.