The first thing is to read through the Performance Tips section of the manual.
The main general suggestions are
- never to benchmark in global scope (because then all your variables are global variables and can change at any time, so the compiler can’t generate optimized code)
- use
@code_warntypeto check for any places where Julia couldn’t infer your types statically (at compile-time), which is often the reason for slow performance.
Also, your code is much easier to read if you wrap it in back-ticks so it shows up highlighted and code-formatted, and when indented properly will look quite nice. The easier you make it on the reader the more likely you are to get more detailed feedback and help.