# 
# Numerical Mathematics and Computing, Fifth Edition
# Ward Cheney & David Kincaid
# Brooks/Cole Publ. Co.
# (c) 2003
#
# file:  lstsq2
#
# linear least squares example
# 
values := [1.0, 2.0, 2.5, 3.0];
Yvalues := [3.7, 4.1, 4.3, 5.0];
A := Matrix([seq([1, Xvalues[k]], k=1..4)]);
b := Vector([seq(Yvalues[k], k=1..4)]);
with(LinearAlgebra):
c := LeastSquares(A,b);
pts := [seq([Xvalues[k], Yvalues[k]], k=1..4)];
bestline := c[1] + c[2]*x;
with(plots):
PLT1 := plot(pts, style=point, symbol=circle):
PLT2 := plot(bestline, x=-1..1):
display(PLT1,PLT2);