todo

非常著名的曲线拟合程序

MISSING FUNCTIONALITY:

* Useful documentation is badly needed.

* In Gala, some stuff that could work for any matrix only works for
  square matrices.

* Lots of work is currently going into the LinearRegression class, which
  is just does simple regression.  All of it should be re-implemented
  in a MultipleRegression class.

* Need to add the "standard", Statistics 101 stuff --- hypothesis
  testing under the usual parametric assumptions, ANOVA,
  multiple regression...

* Need to add cool bootstrapping stuff from Efron & Tibshirani, like
  bootstrapped regressions, BCa intervals...

* Kernel density estimation and smoothing methods.

* Non-linear regressions (like loess), robust linear regressions.

* Time series support.

* Guile bindings!

* All of the other stuff that I've forgotten.