@Tim Holy : Thank you for the web page. I didn't know it. Now I understand a lot of thing :)
@Kristoffer and Patrick: I just read about that in the link that Tim gave me. I did change the code and the time just past from 0.348052 seconds to 0.037768 seconds. Thanks to you all. Now I understand a lot of things and why it was slower than matlab. So now I understand why a lot of people was speaking about Devectorizing matrix calculus. But I think it's sad, because if I want to do this I will use C or C++ . Not a matrixial language like Julia or Matlab. Anyway! So if I'm not mistaking... It's better for me to create a "mul()" function than use the ".*" ?
