GraphMath

Best solution & OLS

Best-fit models as projections onto model subspaces

This chapter develops ordinary least squares through concrete examples of fitting lines, parabolas, planes and paraboloids. It shows how a regression model defines a subspace in the data space, how the best solution is obtained by projection and how changing the model changes the geometry of the fit.

Chapter contents

The PDF is a single document. The page links below are best-effort: most browsers support them, but some viewers may ignore the page hint.

Topic Pages
OLS example 1: fitting a line 1–4
OLS example 2: fitting a parabola with 2 parameters 5–8
Two models for same dataset 9–11
Higher-dimensional set 12–13
Summary: models with one input variable 14–16
Model with 2 input variables 17
Non-linear model with 2 input variables 18–21
Summary: models with > 1 input variable 22–23
Two ways to change a regression model 24–26

Was this chapter helpful?

Quick feedback helps us improve the site.