Following the example in this week lecture, this is a polynomial fitting using Vandermonde matrix
I'm not sure why the interface is not working here.
it works in http://sage.skku.edu
i recommend you copy the code over there to run it properly.
If you have any suggestions or ideas to make the interface work here, please kindly feel free to modify the code
Click to the left again to hide and once more to show the dynamic interactive window