[Pyferret] How to do Multivariate Linear Regression in pyferret?

[ruhuihuang]

We all know it is easy to do Linear Regression with one variable.
Here I was wonder how can we do Multivariate Linear Regression in pyferret?
For example, if we have three variables called X1,X2,X3,how can we realize multivariate Linear fit as the following formula to get all the slopes:
y=Slope1X1+Slope2X2+Slope3*X3+error
Looking forward to anyone's useful help, Thank you so much.