function [t,y]=logpop()
% [T,Y]=LOGPOP. Logarithm of US-population, copied  
% from Harvard Calculus Consortium. 21 data points
% with t time since 1800 in tens of years and y the
% natural logharithm of the US population (in millions).
%
% Matthias Kawski. http://math.la.asu.edu/~kawski
%       Old data file. Comments added in Aug 2000.
t=[-1:1:19]';
% t=[1790:10:1990]';
p=[3.9 5.3 7.2 9.6 12.9 17.1 23.1 31.4 ...
   38.6 50.2 62.9 76.0 92 105.7 122.8  ...
   131.7 150.7 179 205 226.5 248.7]';
y=log(p);