The program below learns a linear relationship between a three-dimensional input and an output.

It downloads and operates on a dataset from Helmut Spaeth, Mathematical Algorithms for Linear Regression, Academic Press, 1991, ISBN 0-12-656460-4.

The data concerns pasture rent structure and grass variety and includes 67 examples. The inputs are

  • the rent per acre of arable land,
  • the number of milk cows per square mile, and
  • the difference between pasturage and arable land

The output is the rental price per acre for this variety of grass. The program includes a loss function as well as a function that calculates the partial derivative of the loss with respect to a specified element of .

Note:

  • This program dpends on the HTTP package, which can generally be installed using the command Pkg.add("HTTP")

  • This program will generally take several seconds to complete execution and output the best-fit vector.